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Sökning: WFRF:(Moore Edward R.B.)

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1.
  • 2019
  • Tidskriftsartikel (refereegranskat)
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2.
  • Kyrpides, Nikos C, et al. (författare)
  • Genomic encyclopedia of bacteria and archaea: sequencing a myriad of type strains.
  • 2014
  • Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1545-7885. ; 12:8
  • Tidskriftsartikel (refereegranskat)abstract
    • Microbes hold the key to life. They hold the secrets to our past (as the descendants of the earliest forms of life) and the prospects for our future (as we mine their genes for solutions to some of the planet's most pressing problems, from global warming to antibiotic resistance). However, the piecemeal approach that has defined efforts to study microbial genetic diversity for over 20 years and in over 30,000 genome projects risks squandering that promise. These efforts have covered less than 20% of the diversity of the cultured archaeal and bacterial species, which represent just 15% of the overall known prokaryotic diversity. Here we call for the funding of a systematic effort to produce a comprehensive genomic catalog of all cultured Bacteria and Archaea by sequencing, where available, the type strain of each species with a validly published name (currently∼11,000). This effort will provide an unprecedented level of coverage of our planet's genetic diversity, allow for the large-scale discovery of novel genes and functions, and lead to an improved understanding of microbial evolution and function in the environment.
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3.
  • Moore, Fiona Porteous, et al. (författare)
  • Endophytic bacterial diversity in poplar trees growing on a BTEX-contaminated site: the characterisation of isolates with potential to enhance phytoremediation.
  • 2006
  • Ingår i: Systematic and applied microbiology. - : Elsevier BV. - 0723-2020. ; 29:7, s. 539-56
  • Tidskriftsartikel (refereegranskat)abstract
    • The diversity of endophytic bacteria found in association with poplar was investigated as part of a larger study to assess the possibility and practicality of using endophytic bacteria to enhance in situ phytoremediation. Endophytic bacteria were isolated from the root, stem and leaf of two cultivars of poplar tree growing on a site contaminated with BTEX compounds. They were further characterised genotypically by comparative sequence analysis of partial 16S rRNA genes and BOX-PCR genomic DNA fingerprinting, and phenotypically by their tolerance to a range of target pollutants, heavy metals and antibiotics. One hundred and 21 stable, morphologically distinct isolates were obtained, belonging to 21 genera, although six isolates could not be identified with confidence to a genus. The endophytic bacteria exhibited marked spatial compartmentalisation within the plant, suggesting there are likely to be species-specific and non-specific associations between bacteria and plants. A number of isolates demonstrated the ability to degrade BTEX compounds or to grow in the presence of TCE. This study demonstrates that within the diverse bacterial communities found in poplar several endophytic strains are present that have the potential to enhance phytoremediation strategies.
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4.
  • Abraham, Wolf-Rainer, et al. (författare)
  • Woodsholea maritima gen. nov., sp. nov., a marine bacterium with a low diversity of polar lipids.
  • 2004
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 54:Pt 4, s. 1227-34
  • Tidskriftsartikel (refereegranskat)abstract
    • Two cauliform bacteria (CM243T and CM251) isolated by J. Poindexter from the Atlantic Ocean were characterized by 16S rRNA gene sequencing, TaqI restriction fragment length polymorphism and single-strand conformation polymorphism analyses of the internally transcribed 16S-23S rDNA spacer (ITS1) region, analysis of fatty acids from cellular lipids, mass spectrometry of polar lipids and physiological properties. The two strains showed very low diversity of polar lipids with diacyl-sulfoquinovosyl glycerols as the predominant lipids. The two bacterial strains were observed to have nearly identical 16S rRNA gene sequences and could not be differentiated by their ITS1 regions. The isolates differed from species of the genus Maricaulis by their 16S rRNA gene sequences, polar lipids and fatty acid patterns. On the basis of the genotypic analyses and estimations of phylogenetic similarities, physiological and chemotaxonomic characteristics, it is proposed that the isolates represent a new genus and species, for which the name Woodsholea maritima gen. nov., sp. nov. (type strain CM243T=VKM B-1512T=LMG 21817T) is proposed.
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5.
  • Alves, G., et al. (författare)
  • Identification of Antibiotic Resistance Proteins via MiCId's Augmented Workflow. A Mass Spectrometry-Based Proteomics Approach
  • 2022
  • Ingår i: Journal of the American Society for Mass Spectrometry. - : American Chemical Society (ACS). - 1044-0305 .- 1879-1123. ; 33:6, s. 917-931
  • Tidskriftsartikel (refereegranskat)abstract
    • Fast and accurate identifications of pathogenic bacteria along with their associated antibiotic resistance proteins are of paramount importance for patient treatments and public health. To meet this goal from the mass spectrometry aspect, we have augmented the previously published Microorganism Classification and Identification (MiCId) workflow for this capability. To evaluate the performance of this augmented workflow, we have used MS/MS datafiles from samples of 10 antibiotic resistance bacterial strains belonging to three different species: Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The evaluation shows that MiCId's workflow has a sensitivity value around 85% (with a lower bound at about 72%) and a precision greater than 95% in identifying antibiotic resistance proteins. In addition to having high sensitivity and precision, MiCId's workflow is fast and portable, making it a valuable tool for rapid identifications of bacteria as well as detection of their antibiotic resistance proteins. It performs microorganismal identifications, protein identifications, sample biomass estimates, and antibiotic resistance protein identifications in 6-17 min per MS/MS sample using computing resources that are available in most desktop and laptop computers. We have also demonstrated other use of MiCId's workflow. Using MS/MS data sets from samples of two bacterial clonal isolates, one being antibiotic-sensitive while the other being multidrug-resistant, we applied MiCId's workflow to investigate possible mechanisms of antibiotic resistance in these pathogenic bacteria; the results showed that MiCId's conclusions agree with the published study.
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6.
  • An, Y., et al. (författare)
  • Therapeutic efficacy of new botulinum toxin identified in CCUG 7968 strain
  • 2021
  • Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 0175-7598 .- 1432-0614. ; 105, s. 8727-8737
  • Tidskriftsartikel (refereegranskat)abstract
    • Botulinum neurotoxin type A (BoNT/A) induces muscle atrophy by cleaving synaptosomal-associated protein 25. Thus, BoNT/A has been actively utilized for the treatment of masseter and gastrocnemius hypertrophy. In this study, INI101 toxin was newly identified from the CCUG 7968 strain, and its therapeutic efficacy was evaluated both in vitro and in vivo. The INI101 toxin showed identical genetic sequence, amino acid sequence, and protein subunit composition to BoNT/A produced from strain Hall A. Electromyography (EMG), and immunofluorescence staining demonstrated that INI101 (at 2 - 8 U/rat) effectively blocked the neuromuscular junction with no toxicity in a rat model. The EMG results showed INI101 toxin-induced weight loss and volume reduction of the gastrocnemius, similar to the effects of Botox (R) (BTX). Histological and immunofluorescence staining was consistent with this EMG result, showing that INI101 toxin caused muscle fiber reduction in the gastrocnemius. Notably, INI101 toxin diffused less into adjacent muscle tissue than BTX, indicating that INI101 toxin may reduce potential side effects due to diffusion into normal tissues. INI101 toxin isolated from the novel strain CCUG 7968 is a newly identified meaningful biopharmaceutical comparable to the conventional BoNT/A in the medical field.
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7.
  • Arahal, David, et al. (författare)
  • The best of both worlds: a proposal for further integration of Candidatus names into the International Code of Nomenclature of Prokaryotes
  • 2024
  • Ingår i: International Journal of Systematic and Evolutionary Microbiology. - 1466-5026 .- 1466-5034. ; 74:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The naming of prokaryotes is governed by the International Code of Nomenclature of Prokaryotes (ICNP) and partially by the International Code of Nomenclature for Algae, Fungi and Plants (ICN). Such codes must be able to determine names of taxa in a universal and unambiguous manner, thus serving as a common language across different fields and activities. This unity is undermined when a new code of nomenclature emerges that overlaps in scope with an established, time-tested code and uses the same format of names but assigns different nomenclatural status values to the names. The resulting nomenclatural confusion is not beneficial to the wider scientific community. Such ambiguity is expected to result from the establishment of the ‘Code of Nomenclature of Prokaryotes Described from DNA Sequence Data’ (‘SeqCode’), which is in general and specific conflict with the ICNP and the ICN. Shortcomings in the interpretation of the ICNP may have exacerbated the incompatibility between the codes. It is reiterated as to why proposals to accept sequences as nomenclatural types of species and subspecies with validly published names, now implemented in the SeqCode, have not been implemented by the International Committee on Systematics of Prokaryotes (ICSP), which oversees the ICNP. The absence of certain regulations from the ICNP for the naming of as yet uncultivated prokaryotes is an acceptable scientific argument, although it does not justify the establishment of a separate code. Moreover, the proposals rejected by the ICSP are unnecessary to adequately regulate the naming of uncultivated prokaryotes. To provide a better service to the wider scientific community, an alternative proposal to emend the ICNP is presented, which would result in Candidatus names being regulated analogously to validly published names. This proposal is fully consistent with previous ICSP decisions, preserves the essential unity of nomenclature and avoids the expected nomenclatural confusion.
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8.
  • Armengaud, J., et al. (författare)
  • The Importance Of Naturally Attenuated Sars-Cov-2 In The Fight Against Covid-19
  • 2020
  • Ingår i: Environmental Microbiology. - : Wiley. - 1462-2912 .- 1462-2920. ; 22:6, s. 1997-2000
  • Tidskriftsartikel (refereegranskat)abstract
    • The current SARS-CoV-2 pandemic is wreaking havoc throughout the world and has rapidly become a global health emergency. A central question concerning COVID-19 is why some individuals become sick and others not. Many have pointed already at variation in risk factors between individuals. However, the variable outcome of SARS-CoV-2 infections may, at least in part, be due also to differences between the viral subspecies with which individuals are infected. A more pertinent question is how we are to overcome the current pandemic. A vaccine against SARS-CoV-2 would offer significant relief, although vaccine developers have warned that design, testing, and production of vaccines may take a year if not longer. Vaccines are based on a handful of different designs (1), but the earliest vaccines were based on live, attenuated virus. As has been the case for other viruses during earlier pandemics, SARS-CoV-2 will mutate and may naturally attenuate over time (2). What makes the current pandemic unique is that, thanks to state-of-the-art nucleic acid sequencing technologies, we can follow in detail how SARS-CoV-2 evolves while it spreads. We argue that knowledge of naturally emerging attenuated SARS-CoV-2 variants across the globe should be of key interest in our fight against the pandemic. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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9.
  • Backrud, Oscar, et al. (författare)
  • Chromobacterium sp. septicemia in Sweden. A clinical case report
  • 2024
  • Ingår i: ANNALS OF CLINICAL MICROBIOLOGY AND ANTIMICROBIALS. - 1476-0711. ; 23:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Chromobacterium is a genus of fourteen species with validly published names, most often found in soil and waters in tropical and subtropical regions around the world. The most well-known species of the genus, C. violaceum, occasionally causes clinically relevant infections; cases of soft tissue infections with septicemia and fatal outcomes have been described. Case presentation Here, we present a clinical case report of a 79-year-old man from Sweden with a soft-tissue infection and septicemia. The pathogen was identified as a strain of Chromobacterium species, but not C. violaceum. The patient was treated with clindamycin and ciprofloxacin and recovered well. Conclusions This case report demonstrates the potential of Chromobacterium species as infectious agents in immunocompetent patients. It also indicates the existence of a novel species.
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10.
  • Bennasar-Figueras, Antoni, et al. (författare)
  • Complete Genome Sequence of Pseudomonas balearica DSM 6083T.
  • 2016
  • Ingår i: Genome Announcements. - 2169-8287. ; 4:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The whole-genome sequence of ITALIC! Pseudomonas balearicaSP1402 (DSM 6083(T)) has been completed and annotated. It was isolated as a naphthalene degrader from water of a lagooning wastewater treatment plant. ITALIC! P.balearicastrains tolerate up to 8.5% NaCl and are considered true marine denitrifiers.
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11.
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12.
  • Boulund, Fredrik, 1985, et al. (författare)
  • Typing and Characterization of Bacteria Using Bottom-up Tandem Mass Spectrometry Proteomics
  • 2017
  • Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 16:6, s. 1052-1063
  • Tidskriftsartikel (refereegranskat)abstract
    • Methods for rapid and reliable microbial identification are essential in modern healthcare. The ability to detect and correctly identify pathogenic species and their resistance phenotype is necessary for accurate diagnosis and efficient treatment of infectious diseases. Bottom-up tandem mass spectrometry (MS) proteomics enables rapid characterization of large parts of the expressed genes of microorganisms. However, the generated data are highly fragmented, making downstream analyses complex. Here we present TCUP, a new computational method for typing and characterizing bacteria using proteomics data from bottom-up tandem MS. TCUP compares the generated protein sequence data to reference databases and automatically finds peptides suitable for characterization of taxonomic composition and identification of expressed antimicrobial resistance genes. TCUP was evaluated using several clinically relevant bacterial species (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae), using both simulated data generated by in silico peptide digestion and experimental proteomics data generated by liquid chromatography-tandem mass spectrometry (MS/MS). The results showed that TCUP performs correct peptide classifications at rates between 90.3 and 98.5% at the species level. The method was also able to estimate the relative abundances of individual species in mixed cultures. Furthermore, TCUP could identify expressed beta-lactamases in an extended spectrum beta-lactamase-producing (ESBL) E.coli strain, even when the strain was cultivated in the absence of antibiotics. Finally, TCUP is computationally efficient, easy to integrate in existing bioinformatics workflows, and freely available under an open source license for both Windows and Linux environments.
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13.
  • Busse, H. J., et al. (författare)
  • Reclassification of Arthrobacter nasiphocae (Collins et al. 2002) as Falsarthrobacter nasiphocae gen. nov., comb. nov
  • 2018
  • Ingår i: International Journal of Systematic and Evolutionary Microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 68:4, s. 1361-1364
  • Tidskriftsartikel (refereegranskat)abstract
    • The original description of Arthrobacter nasiphocae M597/99/10(T) demonstrated that it is distantly related to the type species of the genus Arthrobacter, Arthrobacter globiformis, and that this phylogenetic relationship is reflected by the distinct peptidoglycan type [Lys-Ala(2)-Gly(2-3)-Ala(Gly)] and the features of the quinone system, which is composed of menaquinones MK-9(H-2) and MK-8(H-2). Here, we report a re-evaluation of the taxonomic status of A. nasiphocae. Phylogenetically, it was observed to be only distantly related to the genus Arthrobacter and to the type species of related genera. Re-analysis confirmed the quinone system menaquinones MK-9(H-2) and MK-8(H-2) in A. nasiphocae. Analysis of cell polar lipids showed a profile consisting of the predominant lipids diphosphatidylglycerol, phosphatidylglycerol, dimannosylglyceride, an unidentified phospholipid and an unidentified aminophosphoglycolipid, and several minor unidentified lipids. This profile clearly is different from that of Arthrobacter species. The cell fatty acid profile also showed characteristics that distinguished A. nasiphocae from Arthrobacter species. The phylogenetic distance of A. nasiphocae from any type species of genera within the family Micrococcaceae and the distinct chemotaxonomic traits warrant the reclassification of A. nasiphocae within a novel genus, for which we propose the name Falsarthrobacter nasiphocae gen. nov., comb. nov. The type strain is M597/99/10(T) (=CCUG 42953(T)=CIP 107054(T)=DSM 13988(T)=JCM 11677(T)).
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14.
  • Carvalheira, A., et al. (författare)
  • Acinetobacter portensis sp. Nov. and acinetobacter guerrae sp. nov., isolated from raw meat
  • 2020
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 70:8, s. 4544-4554
  • Tidskriftsartikel (refereegranskat)abstract
    • The taxonomic status of six strains of Acinetobacter obtained from meat samples, collected from supermarkets in Porto, Por-tugal, was investigated using polyphasic analysis. Partial rpoB sequence similarities lower than 95 % to other Acinetobacter species with validly published names led to the hypothesis that these strains represented novel species. This was confirmed based on comparative multilocus sequence analysis, which included the gyrB, recA and 16S rRNA genes, revealing that these strains represented two coherent lineages that were distinct from each other and from all known species. The names Acine-tobacter portensis sp. nov. (comprising four strains) and Acinetobacter guerrae sp. nov. (comprising two strains) are proposed for these novel species. The species status of these two groups was confirmed by low (below 95 %) whole-genome sequence average nucleotide identity values and low (below 70 %) digital DNA–DNA hybridization similarities between the whole-genome sequences of the proposed type strains of each novel species and the representatives of the known Acinetobacter species. Phylogenomic treeing from core genome analysis supported these results. The coherence of each new species lineage was supported by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry differentiation of the species at the protein level, by cellular fatty acid profiles, and by unique and differential combinations of metabolic and physiological properties shared by each novel species. The type strain of A. portensis sp. nov. is AC 877T (=CCUG 68672T=CCM 8789T) and the type strain of A. guerrae sp. nov. is AC 1271T (=CCUG 68674T=CCM 8791T). © 2020 The Authors.
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15.
  • Claverías, Fernanda, et al. (författare)
  • Corynebacterium alimapuense sp. nov., an obligate marine actinomycete isolated from sediment of Valparaíso bay, Chile.
  • 2019
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 69:3, s. 783-790
  • Tidskriftsartikel (refereegranskat)abstract
    • A novel Gram-positive, non-motile, non-spore-forming and aerobic bacterium, designated strain VA37-3T, was isolated from a marine sediment sample collected at 19.2m water depth from Valparaíso bay, Chile. Strain VA37-3T exhibits 97.6% 16S rRNA gene sequence similarity to Corynebacterium marinum D7015T, 96.4% to Corynebacterium humireducens MFC-5T and 96% to Corynebacterium testudinoris M935/96/4T; and a rpoB gene sequence similarity of 85.1% to Corynebacterium pollutisoli VMS11T, both analyses suggesting that strain VA37-3T represents a novel species of Corynebacterium. Physiological testing indicated that strain VA37-3T requires artificial sea water or sodium-supplemented media for growth, representing the first obligate marine actinomycete of the genus Corynebacterium. The genome of the proposed new species, along with the type strains of its most closely related species were sequenced and characterized. In silico genome-based similarity analyses revealed an ANIb of 72.8% (C. marinum D7015T), ANIm of 85.0% (Corynebacterium mustelae DSM 45274T), tetra of 0.90 (Corynebacterium callunae DSM 20147T) and ggdc of 24.7% (Corynebacterium kutscheri DSM 20755T) when compared with the closest related strains. The genomic DNA G+Ccontent of strain VA37-3T was 57.0%. Chemotaxonomic assessment of strain VN6-2T showed the major fatty acids were C18:1ω9c and C16:0. Menaquinones predominantly consisted of MK-8(II-H2). Polar lipids consisted of diphosphatidylglycerol, glycolipids, phosphatidylglycerol, phosphoglycolipid and phosphatidylinositol. Mycolic acids also were present. Overall, the results from phylogenetic, phenotypic and genomic analyses confirmed that strain VA37-3T represents a novel species of the genus Corynebacterium, for which the name Corynebacterium alimapuense sp. nov. is proposed, with VA37-3T as the type strain (=CCUG 69366T=NCIMB 15118T).
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16.
  • Cohen, A., et al. (författare)
  • A multifaceted 'omics' approach for addressing the challenge of antimicrobial resistance
  • 2015
  • Ingår i: Future Microbiology. - : Future Medicine Ltd. - 1746-0913 .- 1746-0921. ; 10:3, s. 365-376
  • Tidskriftsartikel (refereegranskat)abstract
    • The inappropriate use of antibiotics has severe global health and economic consequences, including the emergence of antibiotic-resistant bacteria. A major driver of antibiotic misuse is the inability to accurately distinguish between bacterial and viral infections based on currently available diagnostic solutions. A multifaceted 'omics' approach that integrates personalized patient data such as genetic predisposition to infections (genomics), natural microbiota composition and immune response to infection (proteomics and transcriptomics) together with comprehensive pathogen profiling has the potential to help physicians improve their antimicrobial prescribing practices. In this respect, the EU has funded a multidisciplinary project (TAILORED-Treatment) that will develop novel omics-based personalized treatment schemes that have the potential to reduce antibiotic consumption, and help limiting the spread of antibiotic resistance.
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17.
  • Cotta, Michael A, et al. (författare)
  • Robinsoniella peoriensis gen. nov., sp. nov., isolated from a swine-manure storage pit and a human clinical source.
  • 2009
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 59:1, s. 150-155
  • Tidskriftsartikel (refereegranskat)abstract
    • A polyphasic taxonomic study was performed on six strains of an unknown Gram-positive, non-motile, spore-forming, short oval to rod-shaped bacterium isolated from a swine-manure storage pit. In addition to these strains, an isolate deposited in the Culture Collection of the University of Göteborg (Sweden) was found to be biochemically related to the manure strains. The major end products of metabolism included acetate and succinate but not butyrate. Comparative 16S rRNA gene sequencing confirmed that all these isolates were closely related to each other and formed a hitherto unknown lineage within the clostridial rRNA XIVa cluster of organisms. On the basis of phylogenetic, biochemical and phenotypic evidence, it is proposed that the unknown bacterium represents a novel genus and species, for which the name Robinsoniella peoriensis gen. nov., sp. nov. is proposed. The type strain of Robinsoniella peoriensis is PPC31T (=CCUG 48729T =NRRL B-23985T).
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18.
  • Cotta, M. A., et al. (författare)
  • Two novel species Enterococcus lemanii sp nov and Enterococcus eurekensis sp nov., isolated from a swine-manure storage pit
  • 2013
  • Ingår i: Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology. - : Springer Science and Business Media LLC. - 0003-6072. ; 103:1, s. 89-98
  • Tidskriftsartikel (refereegranskat)abstract
    • A polyphasic taxonomic study using morphological, biochemical, chemotaxonomic and molecular genetic methods was performed on six strains of unknown Gram-positive, nonspore-forming, facultative anaerobic coccus-shaped bacteria isolated from a swine-manure storage pit. On the basis of the 16S rRNA, RNA polymerase alpha-subunit (rpoA) and 60 kDa chaperonin (cpn60) gene sequence analyses, it was shown that all the isolates were enterococci but formed two separate lines of descent. Pairwise 16S rRNA gene sequence comparisons demonstrated that the two novel organisms were most closely related to each other (97.9 %) and to Enterococcus aquimarinus (97.8 %). Both organisms contained major amounts of C-16:0, C-16:1 omega 7c, C-16:1 omega 7c, and C-18:1 omega 7c/12t/9t as the major cellular fatty acids. Based on biochemical, chemotaxonomic and phylogenetic evidence, the names Enterococcus lemanii sp. nov. (type strain PC32(T) = CCUG 61260(T) = NRRL B-59661(T)) and Enterococcus eurekensis sp. nov. (type strain PC4B(T) = CCUG 61259(T) = NRRL B-59662(T)) are proposed for these hitherto undescribed species.
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19.
  • Crespi, S., et al. (författare)
  • Legionella maioricensis sp. nov., a new species isolated from the hot water distribution systems of a hospital and a shopping center during routine sampling
  • 2023
  • Ingår i: International Journal of Systematic and Evolutionary Microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 73:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Two Legionella- like strains isolated from hot water distribution systems in 2012 have been characterized phenotypically, bio-chemically and genomically in terms of DNA relatedness. Both strains, HCPI- 6T and EUR- 108, exhibited biochemical pheno-typic profiles typical of Legionella species. Cells were Gram-negative motile rods which grew on BCYE alpha agar but not on blood agar and displayed phenotypic characteristics typical of the family Legionellaceae, including a requirement for L-cysteine and testing catalase positive. Both strains were negative for oxidase, urease, nitrate reduction and hippurate negative, and non -fermentative. The major ubiquinone was Q12 (59.4 % HCPI- 6T) and the dominant fatty acids were C16:1 omega 7c (28.4 % HCPI- 6T, 216 % EUR- 108), C16: 0 iso (222.5 % and 213 %) and C15: 0 anteiso (19.5 % and 223.5 %, respectively). The percent G+C content of genomic DNA was determined to be 39.3 mol %. The 16S rRNA gene, mip sequence and comparative genome sequence -based analyses (average nucleotide identity, ANI; digital DNA-DNA hybridization, dDDH; and phylogenomic treeing) demonstrated that the strains represent a new species of the genus Legionella. The analysis based on the 16S rRNA gene sequences showed that the sequence similarities for both strains ranged from 98.8-90.1 % to other members of the genus. The core genome- based phylogenomic tree (protein-concatemer tree based on concatenation of 418 proteins present in single copy) revealed that these two strains clearly form a separate cluster within the genus Legionella. ANI and dDDH values confirmed the distinctiveness of the strains. Based on the genomic, genotypic and phenotypic findings from a polyphasic study, the isolates are considered to represent a single novel species, for which the name Legionella maioricensis sp. nov. is proposed. The type strain is HCPI- 6T (=CCUG 75071T=CECT 30569T).
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20.
  • Cuadrado, Virginia, et al. (författare)
  • Cupriavidus pampae sp. nov., a novel herbicide-degrading bacterium isolated from agricultural soil
  • 2010
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 60:11, s. 2606-2612
  • Tidskriftsartikel (refereegranskat)abstract
    • A bacterial consortium able to degrade the herbicide 4-(2,4-dichlorophenoxy) butyric acid (2,4-DB) was obtained from an agricultural soil of the Argentinean Humid Pampa region which has a history of long-term herbicide use. Four bacterial strains were isolated from the consortium and identified as members of the genera Cupriavidus, Labrys and Pseudomonas. A polyphasic systematic analysis was carried out on strain CPDB6(T), the member of the 2,4-DB-degrading consortium able to degrade 2,4-DB as a sole carbon and energy source. The Gram-negative, rod-shaped, motile, non-sporulating, non-fermenting bacterium was shown to belong to the genus Cupriavidus on the basis of 16S rRNA gene sequence analyses. Strain CPDB6(T) did not reduce nitrate, which differentiated it from the type species of the genus, Cupriavidus necator; it did not grow in 0.5-4.5% NaCl, although most species of Cupriavidus are able to grow at NaCl concentrations as high as 1.5%; and it was able to deamidate acetamide, which differentiated it from all other species of Cupriavidus. DNA-DNA hybridization data revealed low levels of genomic DNA similarity (less than 30%) between strain CPDB6(T) and the type strains of Cupriavidus species with validly published names. The major cellular fatty acids detected were cis-9-hexadecenoic (16:1ω7c) and hexadecanoic (16:0) acids. On the basis of phenotypic and genotypic characterizations, strain CPDB6(T) was recognized as a representative of a novel species within the genus Cupriavidus. The name Cupriavidus pampae sp. nov. is proposed, with strain CPDB6(T) (=CCUG 55948(T)=CCM-A-29:1289(T)) as the type strain.
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21.
  • Cumsille, A., et al. (författare)
  • Exploring the biosynthetic gene clusters in Brevibacterium: a comparative genomic analysis of diversity and distribution
  • 2023
  • Ingår i: Bmc Genomics. - 1471-2164. ; 24:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Exploring Brevibacterium strains from various ecosystems may lead to the discovery of new antibiotic-producing strains. Brevibacterium sp. H-BE7, a strain isolated from marine sediments from Northern Patagonia, Chile, had its genome sequenced to study the biosynthetic potential to produce novel natural products within the Brevibacterium genus. The genome sequences of 98 Brevibacterium strains, including strain H-BE7, were selected for a genomic analysis. A phylogenomic cladogram was generated, which divided the Brevibacterium strains into four major clades. A total of 25 strains are potentially unique new species according to Average Nucleotide Identity (ANIb) values. These strains were isolated from various environments, emphasizing the importance of exploring diverse ecosystems to discover the full diversity of Brevibacterium. Pangenome analysis of Brevibacterium strains revealed that only 2.5% of gene clusters are included within the core genome, and most gene clusters occur either as singletons or as cloud genes present in less than ten strains. Brevibacterium strains from various phylogenomic clades exhibit diverse BGCs. Specific groups of BGCs show clade-specific distribution patterns, such as siderophore BGCs and carotenoid-related BGCs. A group of clade IV-A Brevibacterium strains possess a clade-specific Polyketide synthase (PKS) BGCs that connects with phenazine-related BGCs. Within the PKS BGC, five genes, including the biosynthetic PKS gene, participate in the mevalonate pathway and exhibit similarities with the phenazine A BGC. However, additional core biosynthetic phenazine genes were exclusively discovered in nine Brevibacterium strains, primarily isolated from cheese. Evaluating the antibacterial activity of strain H-BE7, it exhibited antimicrobial activity against Salmonella enterica and Listeria monocytogenes. Chemical dereplication identified bioactive compounds, such as 1-methoxyphenazine in the crude extracts of strain H-BE7, which could be responsible of the observed antibacterial activity. While strain H-BE7 lacks the core phenazine biosynthetic genes, it produces 1-methoxyphenazine, indicating the presence of an unknown biosynthetic pathway for this compound. This suggests the existence of alternative biosynthetic pathways or promiscuous enzymes within H-BE7's genome.
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22.
  • Dos Santos, V A P Martins, et al. (författare)
  • Insights into the genomic basis of niche specificity of Pseudomonas putida KT2440.
  • 2004
  • Ingår i: Environmental microbiology. - : Wiley. - 1462-2912 .- 1462-2920. ; 6:12, s. 1264-86
  • Tidskriftsartikel (refereegranskat)abstract
    • A major challenge in microbiology is the elucidation of the genetic and ecophysiological basis of habitat specificity of microbes. Pseudomonas putida is a paradigm of a ubiquitous metabolically versatile soil bacterium. Strain KT2440, a safety strain that has become a laboratory workhorse worldwide, has been recently sequenced and its genome annotated. By drawing on both published information and on original in silico analysis of its genome, we address here the question of what genomic features of KT2440 could explain or are consistent with its ubiquity, metabolic versatility and adaptability. The genome of KT2440 exhibits combinations of features characteristic of terrestrial, rhizosphere and aquatic bacteria, which thrive in either copiotrophic or oligotrophic habitats, and suggests that P. putida has evolved and acquired functions that equip it to thrive in diverse, often inhospitable environments, either free-living, or in close association with plants. The high diversity of protein families encoded by its genome, the large number and variety of small aralogous families, insertion elements, repetitive extragenic palindromic sequences, as well as the mosaic structure of the genome (with many regions of 'atypical' composition) and the multiplicity of mobile elements, reflect a high functional diversity in P. putida and are indicative of its evolutionary trajectory and adaptation to the diverse habitats in which it thrives. The unusual wealth of determinants for high affinity nutrient acquisition systems, mono- and di-oxygenases, oxido-reductases, ferredoxins and cytochromes, dehydrogenases, sulfur metabolism proteins, for efflux pumps and glutathione-S-transfereases, and for the extensive array of extracytoplasmatic function sigma factors, regulators, and stress response systems, constitute the genomic basis for the exceptional nutritional versatility and opportunism of P. putida , its ubiquity in diverse soil, rhizosphere and aquatic systems, and its renowned tolerance of natural and anthropogenic stresses. This metabolic diversity is also the basis of the impressive evolutionary potential of KT2440, and its utility for the experimental design of novel pathways for the catabolism of organic, particularly aromatic, pollutants, and its potential for bioremediation of soils contaminated with such compounds as well as for its application in the production of high-added value compounds.
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23.
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24.
  • Duran, R. E., et al. (författare)
  • Genomic and Physiological Traits o the Marine Bacterium Alcaligenes aquatilis QD168 Isolated From Quintero Bay, Central Chile, Reveal a Robust Adaptive Response to Environmental Stressors
  • 2019
  • Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • Alcaligenes aquatilis QD168 is a marine, aromatic hydrocarbon-degrading bacterium, isolated from an oil-polluted sediment of Quintero Bay, an industrial-coastal zone that has been chronically impacted by diverse pollutants. The aims of this study were to characterize the phylogenomic positions of Alcaligenes spp. and to characterize the genetic determinants and the physiological response of A. aquatilis QD168 to model environmental stressors (benzene, oxidizing agents, and salt). Phylogenomic analyses, using 35 housekeeping genes, clustered A. aquatilis QD168 with four other strains of Alcaligenes spp. (A. aquatilis BU33N, A. faecalis JQ135, A. faecalis UBA3227, and A. faecalis UBA7629). Genomic sequence analyses of A. aquatilis QD168 with 25 Alcaligenes spp., using ANIb, indicated that A. aquatilis BU33N is the closest related strain, with 96.8% ANIb similarity. Strain QD168 harbors 95 genes encoding proteins of seven central catabolic pathways, as well as sixteen peripheral catabolic pathways/reactions for aromatic compounds. A. aquatilis QD168 was able to grow on 3-hydroxybenzoate, 4-hydroxybenzoate, benzoate, benzene, 3-hydroxycinnamate, cinnamate, anthranilate, benzamide, 4-aminobenzoate, nicotinate, toluene, biphenyl and tryptophan, as sole carbon or nitrogen source. Benzene degradation was further analyzed by growth, metabolite identification and gene expression analyses. Benzene strongly induced the expression of the genes encoding phenol hydroxylase (dmpP) and catechol 1,2-dioxygenase (catA). Additionally, 30 genes encoding transcriptional regulators, scavenging enzymes, oxidative damage repair systems and isozymes involved in oxidative stress response were identified. Oxidative stress response of strain QD168 to hydrogen peroxide and paraquat was characterized, demonstrating that A. aquatilis QD168 is notably more resistant to paraquat than to H2O2. Genetic determinants (47 genes) for osmoprotective responses were identified, correlating with observed high halotolerance by strain QD168. The physiological adaptation of A. aquatilis QD168 to environmental stressors such as pollutants, oxidative stress and salinity may be exploited for bioremediation of oil-polluted saline sites.
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25.
  • Emilsson, Gustav, 1989, et al. (författare)
  • Identifying bacteria using DNA binding maps
  • 2013
  • Ingår i: 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013; Freiburg; Germany; 27 October 2013 through 31 October 2013. - 9781632666246 ; 1, s. 473-475
  • Konferensbidrag (refereegranskat)abstract
    • We have developed an assay, based on nanofluidic channels and fluorescence microscopy, for optical mapping of DNA based on competitive binding between two molecules - one fluorescent and one sequence selective. From the experimental data we can extract binding constants for the two competing DNA binders, which may be subsequently used to calculate a theoretical reference map of any DNA with known sequence. The goal is to create a method for fast identification of bacteria from single DNA molecules without the need for additional cultivation or amplification. We here demonstrate a proof-of-principle experiment on phage DNA and furthermore show that the method can be used to distinguish between two strains of E. coli DNA and to map pieces of DNA onto the full genome.
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26.
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27.
  • Germain, K, et al. (författare)
  • Colonisation of poplar trees by gfp-expressing bacterial endophytes
  • 2004
  • Ingår i: FEMS Microbiology Ecology. - 0168-6496. ; 48:1, s. 109-118
  • Tidskriftsartikel (refereegranskat)abstract
    • With the exception of nitrogen fixing bacteria, there is little known about the colonisation patterns or population sizes of bacterial endophytes in deciduous trees. This study describes the isolation, identification, construction and re-colonisation patterns of three green fluorescent protein(gfp):kanamycinR labelled bacterial endophytes when re-introduced into poplar trees, their original host plant. Two of these endophytes showed considerable colonisation in the roots and stems of inoculated plants. gfp expressing cells of all three strains were observed to colonise the xylem tissue of the root. All three strains proved to be efficient rhizosphere colonisers, supporting the theory that the rhizosphere can serve as a source of bacterial endophytes.
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28.
  • Gomila, Margarita, et al. (författare)
  • Achromobacter marplatensis sp. nov., isolated from a pentachlorophenol contaminated soil.
  • 2011
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 61:9, s. 2231-2237
  • Tidskriftsartikel (refereegranskat)abstract
    • A polyphasic taxonomic approach was applied for the study of a Gram negative bacterium (B2(T)) isolated from soil by selective enrichment with pentachlorophenol. The 16S rRNA gene sequence analysis of strain B2(T) showed that this strain belongs to the genus Achromobacter, within the Betaproteobacteria. The 16S rRNA gene sequence possessing more than 99% similarity to the sequences of the type strains of all species in Achromobacter, with the highest sequence similarities to those of A. spanius CCM 7183(T) and A. piechaudii CCM 2986(T) (99.8 %). On the basis of phylogenetic analysis, genomic DNA-DNA similarities and phenotypic characteristics, including chemotaxonomic (cell fatty acid profile) analysis, a novel species is proposed, Achromobacter marplatensis sp. nov., with the type strain B2(T) (= CCM 7608(T) = CCUG 56371(T) = CECT 7342(T)).
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29.
  • Gomila, Margarita, et al. (författare)
  • Description of Pelomonas aquatica sp. nov. and Pelomonas puraquae sp. nov., isolated from industrial and haemodialysis water.
  • 2007
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 57:11, s. 2629-2635
  • Tidskriftsartikel (refereegranskat)abstract
    • Three Gram-negative, rod-shaped, non-spore-forming bacteria (strains CCUG 52769T, CCUG 52770 and CCUG 52771) isolated from haemodialysis water were characterized taxonomically, together with five strains isolated from industrial waters (CCUG 52428, CCUG 52507, CCUG 52575T, CCUG 52590 and CCUG 52631). Phylogenetic analysis based on 16S rRNA gene sequences indicated that these isolates belonged to the class Betaproteobacteria and were related to the genus Pelomonas, with 16S rRNA gene sequence similarities higher than 99% with the only species of the genus, Pelomonas saccharophila and to Pseudomonas sp. DSM 2583. The type strains of Mitsuaria chitosanitabida and Roseateles depolymerans were their closest neighbours (97.9 and 97.3% 16S rRNA gene sequence similarity, respectively). Phylogenetic analysis was also performed for the internally transcribed spacer region and for three genes [hoxG (hydrogenase), cbbL/cbbM (Rubisco) and nifH (nitrogenase)] relevant for the metabolism of the genus Pelomonas. DNA-DNA hybridization, major fatty acid composition and phenotypical analyses were carried out, which included the type strain of Pelomonas saccharophila obtained from different culture collections (ATCC 15946T, CCUG 32988T, DSM 654T, IAM 14368T and LMG 2256T), as well as M. chitosanitabida IAM 14711T and R. depolymerans CCUG 52219T. Results of DNA-DNA hybridization, physiological and biochemical tests supported the conclusion that strains CCUG 52769, CCUG 52770 and CCUG 52771 represent a homogeneous phylogenetic and genomic group, including strain DSM 2583, clearly differentiated from the industrial water isolates and from the Pelomonas saccharophila type strain. On the basis of phenotypic and genotypic characteristics, these strains belong to two novel species within the genus Pelomonas, for which the names Pelomonas puraquae sp. nov. and Pelomonas aquatica sp. nov. are proposed. The type strains of Pelomonas puraquae sp. nov. and Pelomonas aquatica sp. nov. are CCUG 52769T (=CECT 7234T) and CCUG 52575T (=CECT 7233T), respectively.
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30.
  • Gomila, Margarita, et al. (författare)
  • Description of Roseateles aquatilis sp nov and Roseateles terrae sp nov., in the class Betaproteobacteria, and emended description of the genus Roseateles
  • 2008
  • Ingår i: International Journal of Systematic and Evolutionary Microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 58, s. 6-11
  • Tidskriftsartikel (refereegranskat)abstract
    • Three strains of aerobic Gram-negative bacilli, two isolated from industrial water and freshwater (strains CCUG 48205T and CCUG 52220) and the third from soil (strain CCUG 52222T), were analysed phenotypically and genotypically to clarify their taxonomic classification. 16S rRNA gene sequence analysis revealed that the three strains were located on the same phylogenetic branch, closely related to Roseateles depolymerans, the only recognized species in the genus. DNA–DNA hybridization studies, analyses of fatty acid contents, and physiological and biochemical tests supported the proposal of two novel species, Roseateles aquatilis sp. nov. (type strain, CCUG 48205T=CECT 7248T) and Roseateles terrae sp. nov. (type strain, CCUG 52222T=CECT 7247T).
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31.
  • Gomila, Margarita, et al. (författare)
  • Genotypic and phenotypic applications for the differentiation and species-level identification of achromobacter for clinical diagnoses.
  • 2014
  • Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 9:12
  • Tidskriftsartikel (refereegranskat)abstract
    • The Achromobacter is a genus in the family Alcaligenaceae, comprising fifteen species isolated from different sources, including clinical samples. The ability to detect and correctly identify Achromobacter species, particularly A. xylosoxidans, and differentiate them from other phenotypically similar and genotypically related Gram-negative, aerobic, non-fermenting species is important for patients with cystic fibrosis (CF), as well as for nosocomial and other opportunistic infections. Traditional phenotypic profile-based analyses have been demonstrated to be inadequate for reliable identifications of isolates of Achromobacter species and genotypic-based assays, relying upon comparative 16S rRNA gene sequence analyses are not able to insure definitive identifications of Achromobacter species, due to the inherently conserved nature of the gene. The uses of alternative methodologies to enable high-resolution differentiation between the species in the genus are needed. A comparative multi-locus sequence analysis (MLSA) of four selected 'house-keeping' genes (atpD, gyrB, recA, and rpoB) assessed the individual gene sequences for their potential in developing a reliable, rapid and cost-effective diagnostic protocol for Achromobacter species identifications. The analysis of the type strains of the species of the genus and 46 strains of Achromobacter species showed congruence between the cluster analyses derived from the individual genes. The MLSA gene sequences exhibited different levels of resolution in delineating the validly published Achromobacter species and elucidated strains that represent new genotypes and probable new species of the genus. Our results also suggested that the recently described A. spritinus is a later heterotypic synonym of A. marplatensis. Strains were analyzed, using whole-cell Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight mass spectrometry (MALDI-TOF MS), as an alternative phenotypic profile-based method with the potential to support the identifications determined by the genotypic DNA sequence-based MLSA. The MALDI-TOF MS data showed good accordance in strain groupings and identifications by the MLSA data.
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32.
  • Gomila, Margarita, et al. (författare)
  • Kinneretia asaccharophila gen. nov., sp. nov., isolated from a freshwater lake, a member of the Rubrivivax branch of the family Comamonadaceae.
  • 2010
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 60:4, s. 809-814
  • Tidskriftsartikel (refereegranskat)abstract
    • A strictly aerobic, Gram-negative bacterium, strain KIN192(T), isolated from fresh water from Lake Kinneret, Israel, was examined using a polyphasic approach to characterize and clarify its phylogenetic and taxonomic position. Sequences of the 16S rRNA and gyrB genes and ITS1 revealed close relationships to species of the genera Pelomonas, Mitsuaria and Roseateles, in the Rubrivivax branch of the family Comamonadaceae of the Betaproteobacteria. Physiological and biochemical tests, cellular fatty acid analysis and DNA-DNA hybridizations indicated that this strain should be assigned to a new genus and species in the Rubrivivax phylogenetic branch, for which the name Kinneretia asaccharophila gen. nov., sp. nov., is proposed. The type strain of Kinneretia asaccharophila is strain KIN192(T) (=CCUG 53117(T) =CECT 7319(T)).
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33.
  • Gomila, Margarita, et al. (författare)
  • Molecular Techniques for the Identification of Clinical and Environmental Achromobacter strains
  • 2009
  • Ingår i: FEMS 2009 - 3rd Congress of European Microbiologists.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Background: The genus Achromobacter (βetaproteobacteria) comprises six species isolated from different sources, most from clinical samples. The ability to detect and correctly identify A. xylosoxidans and related Gram-negative, non-fermenting species is essential for patients with cystic fibrosis, as well as in nosocomial infections. Traditional phenotyping is not adequate for reliable, definitive identifications of Achromobacter species. Furthermore, sequence analyses of 16S rRNA gene sequences are also not able insure accurate identification of Achromobacter species, due to the limited resolution of the rRNA genes (greater than 98.5% to each other). Objectives: The objective of this study has been to establish a genotypic, multi-locus sequence analysis (MLSA), analysis for the reliable, definitive and cost-effective identification of Achromobacter species, and to apply the molecular tools for typing and identification of clinical isolates. Methods: 1) Selection of phenotypically well-described strains of Achromobacter species isolated from different sources (clinical and environmental). 2) Development of a MLSA strategy based on sequences of 16S rRNA, inter-genic spacer regions (IGS1), DNA gyrase subunit B (gyrB), and RNA polymerase subunit B (rpoB). 3) Comparison and correlation of MLSA data with other methodologies: DNA-DNA hybridisation; fingerprinting analysis; cellular fatty acids analysis; and MALDI-TOF mass spectrometry analyses. Results: Individual phylogenetic trees, as well as combined datasets were compared. The combined analysis of the MLSA data provided differentiation at the intra- and the interspecies levels and reliable identifications of isolates of Achromobacter spp. Conclusions: The MLSA methodology described allows for the rapid and reliable identification of the Achromobacter species, distinguished from related Gram-negative non-fermenting organisms, and is also useful for strain differentiation and typing in molecular epidemiological studies.
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34.
  • Gonzales-Siles, Lucia, et al. (författare)
  • A Pangenome Approach for Discerning Species-Unique Gene Markers for Identifications of Streptococcus pneumoniae and Streptococcus pseudopneumoniae
  • 2020
  • Ingår i: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media SA. - 2235-2988. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • Correct identifications of isolates and strains of the Mitis-Group of the genus Streptococcus are particularly difficult, due to high genetic similarity, resulting from horizontal gene transfer and homologous recombination, and unreliable phenotypic and genotypic biomarkers for differentiating the species. Streptococcus pneumoniae and Streptococcus pseudopneumoniae are the most closely related species of the clade. In this study, publicly-available genome sequences for Streptococcus pneumoniae and S. pseudopneumoniae were analyzed, using a pangenomic approach, to find candidates for species-unique gene markers; ten species-unique genes for S. pneumoniae and nine for S. pseudopneumoniae were identified. These species-unique gene marker candidates were verified by PCR assays for identifying S. pneumoniae and S. pseudopneumoniae strains isolated from clinical samples. All determined species-level unique gene markers for S. pneumoniae were detected in all S. pneumoniae clinical isolates, whereas fewer of the unique S. pseudopneumoniae gene markers were present in more than 95% of the clinical isolates. In parallel, taxonomic identifications of the clinical isolates were confirmed, using conventional optochin sensitivity testing, targeted PCR-detection for the "Xisco" gene, as well as genomic ANIb similarity analyses for the genome sequences of selected strains. Using mass spectrometry-proteomics, species-specific peptide matches were observed for four of the S. pneumoniae gene markers and for three of the S. pseudopneumoniae gene markers. Application of multiple species-level unique biomarkers of S. pneumoniae and S. pseudopneumoniae, is proposed as a protocol for the routine clinical laboratory for improved, reliable differentiation, and identification of these pathogenic and commensal species.
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35.
  • Gonzales-Siles, Lucia, et al. (författare)
  • Identification and capsular serotype sequetyping of Streptococcus pneumoniae strains
  • 2019
  • Ingår i: Journal of Medical Microbiology. - : Microbiology Society. - 0022-2615 .- 1473-5644. ; 68:8, s. 1173-1188
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose. Correct serotype identification of Streptococcus pneumoniae (pneumococcus) is important for monitoring disease epidemiology and assessing the impacts of pneumococcal vaccines. Furthermore, correct identification and differentiation of the pathogenic S. pneumoniae from closely related commensal species of the mitis group of the genus Streptococcus are essential for correct serotype identification. Methodology. A new protocol for determining the existing 98 serotypes of pneumococcus was developed, applying two PCR amplifications and amplicon sequencing, using newly designed internal primers. The new protocol was validated using S. pneumoniae genome sequences, reference strains with confirmed serotypes and clinical isolates, and comparing the results with those from the traditional Quellung reaction or antiserum panel gel precipitation, in addition to real-time PCR analysis. The taxonomic identifications of 422 publicly available (GenBank) genome sequences of S. pneumoniae, Streptococcus pseudopneumoniae and Streptococcus mitis were assessed by whole-genome sequence average nucleotide identity based on blast (ANIb) analysis. Results. The proposed sequetyping protocol generates a 1017 bp whole cpsB region sequence, increasing resolution for serotype identification in pneumococcus isolates. The identifications of all GenBank genome sequences of S. pneumoniae were confirmed, whereas most of the S. pseudopneumoniae and almost all of the S. mitis genome sequences did not fulfil the ANIb thresholds for species-level identification. The housekeeping biomarker gene, groEL, correctly identified S. pneumoniae but often misclassified S. pseudopneumoniae and S. mitis as S. pneumoniae. Conclusions. These studies affirm the importance of applying reliable identification protocols for S. pneumoniae before serotyping; our protocols provide reliable diagnostic tools, as well as an improved workflow, for serotype identification of pneumococcus and differentiation of serogroup 6 types.
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36.
  • Gonzales-Siles, Lucia, et al. (författare)
  • Mass Spectrometry Proteotyping for detection, identification characterization and diagnostics of infectious bacteria in clinical respiratory-tract samples
  • 2016
  • Ingår i: 11th International Meeting on Microbial Epidemiological Markers (IMMEM XI) 9 - 12 March 2016, Estoril, Portugal.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Background. Lower respiratory tract infection (LRTI) is the leading cause of childhood deaths in most developing countries and the world (?) and are the most common causes of hospital and out-patient visits within the EU, comprising 1 of 3 admissions annually. In general, the over-prescription and use of broad-spectrum antibiotics are common practices that lead to the evolution and development of resistance in infectious bacteria and will lead to loss of time and resources in patient handling and adverse patient outcomes. Conventional approaches have depended upon cultivation of bacteria with subsequent testing for antibiotic sensitivity. Therefore, reliable and time-effective microbiological diagnostics are essential for more effective treatment of respiratory infections. In this project, we apply state-of-the-art proteomics techniques for identifications of pathogens and antibiotic resistance from clinical samples, without prior cultivation. Material and methods. Nasopharyngeal swab samples were collected, in commercial Amies medium supplemented with 5x STGG, as a part of the EU-TAILORED-Treatment project (www.tailored-treatment.eu/). Samples were stored at -20°C until analyses. Different protocols for removal of human cells and mucus were tested, including non-ionic detergents, i.e., Igepal, Saponin, Urea-Chaps, as well as cytolysis. Samples were concentrated and analyzed by ‘proteotyping’ (1), using a Lipid-based Protein Immobilization (LPITM) technology (WO2006068619), in which intact bacterial cells or cell fractions are bound to a surface. Peptides were generated, using enzymatic digestion, and then separated and analyzed, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The mass spectra profiles were compared to a database of reference peptide sequences, consisting of all complete genomes of the NCBI Reference Sequence (RefSeq) Database. Results were confirmed by standard microbiology, including cultivation of bacteria in selective media, MALDI-TOF MS analyses and qPCR. Results. Proteotyping applied to clinical samples demonstrated that the number of viable bacteria and detected proteins determined were ten-times higher when nasal swabs were stored in Amies media supplemented with STGG 5X media compared to Amies media without STGG, after 1 and 2 months of storage at -70C. Among the different protocols tested to remove human biomaterial, all treatments proved effective to varying degrees, although the Igepal treatment was able to retain the highest number of discriminatory peptides. Using proteotyping, we were able to identify the pathogenic bacteria directly within clinical samples (nasopharyngeal and nasal swabs) that had been identified to be positive for respiratory infectious bacteria by standard methodologies at clinical bacteriology laboratories at Sahlgrenska University Hospital (Sweden) or Universitair Medisch Centrum Utrecht (Netherlands). Conclusions. Proteotyping of infectious bacteria, using tandem LC-MS/MS enabled the differentiation and identification of infectious bacteria in clinical samples from LRTIs. It has high levels of resolution and highly reproducible detection of protein biomarkers. Proteotyping identified biomarkers for species- and sub-species-level strain discrimination and antibiotic resistance, all from single MS analyses. 1) Karlsson et al., 2015. Syst. Appl. Microbiol. 38 :246-257.
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37.
  • Gonzales-Siles, Lucia, et al. (författare)
  • Mass Spectrometry Proteotyping of Streptococcus pneumoniae and commensal Streptococcus: identification of biomarkers for infectious strain characterization
  • 2016
  • Ingår i: 26th ECCMID 2016 Amsterdam, The Netherlands. 9 - 12 April 2016.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Background: Streptococcus pneumoniae (pneumococcus) is the leading cause of community-acquired pneumonia, with morbidity and mortality worldwide. S. pneumoniae belongs to the S. mitis-Group (viridans streptococci), phenotypically and genotypically similar to commensal species of the upper respiratory tract, S. mitis, S. oralis, and S. pseudopneumoniae, causing problems for identifications in clinical laboratories. In this project, we apply state-of-the-art proteomics for Streptococcus spp. 'proteotyping'; identifying and characterizing protein biomarkers for species-level identification, antibiotic resistance, virulence and strain typing for epidemiological analyses (1). Material/methods: Bacterial proteins, from intact bacteria or cell fractions, are bound to a membrane surface, using patented (WO2006068619) FlowCell (LPITM) technology. Peptides are generated from the bound proteins, by enzymatic digestion, separated and analyzed, using LC-MS/MS. The mass spectra profiles are compared to reference peptide sequences and whole genome sequence (wgs) data of the NCBI RefSeq Database. The S. mitis-Group specie, S. pneumoniae, S. mitis, S. oralis, S. psedopneumoniae, as well as the more distantly-related, Group A Streptococcus (GAS) species, S. pyogenes , were analyzed individually and in mixtures, to demonstrate the resolution of proteotyping for differentiating bacteria. Results: Using proteotyping protocols, S. pneumoniae were detected and differentiated from other streptococci, S. mitis, S. oralis, S. psedopneumoniae and the more distant relative, S. pyogenes, by identification of unique discriminatory peptides. Metabolic protein biomarkers were identified, including for antibiotic resistance and virulence. It was possible to find discriminatory biomarkers for a target species when analyzing 1:1 mixes of S. pneumoniae and other species from the S. mitis-Group. The different strains of S. pneumoniae, analyzed in different ratio combinations, were successfully differentiated and identified. For successful proteotyping, a comprehensive and accurate genomic database was observed to be key for obtaining reliable peptide matching and proteotyping data. Importantly, because of observed high rates of misclassified wgs data in the public databases, the taxonomic classifications of genomes in GenBank were analyzed against reference type strain genomes of target species by calculating wgs similarities, using Average Nucleotide Identity with BLAST (ANIb). While wgs data for S. pneumoniae were confirmed to be classified correctly, approximately one-third of wgs data for other species of the S. mitis-Group were determined to be misclassified. Streptococci strains that could not be identified, using standard genotypic and phenotypic approaches, were characterized by proteotyping and genome sequencing to establish their taxonomy and biomarker features to enhance species database matching. Conclusions: Proteotyping enables differentiation, identification and characterization of pneumococcus from the most closely related species attaining, as well, strain-level discrimination from single LC-MS/MS analyses. The protocol enhances identification and characterization of pathogenic bacterial isolates through identifications of expressed biomarkers, ultimately for cultivation-independent analyses of clinical samples. 1) Karlsson et al., 2015. Syst Appl Microbiol. 38:246-257.
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38.
  • Grankvist, Anna, et al. (författare)
  • Multi-locus sequence analysis (MLSA) of clinical "CandidatusNeoehrlichia mikurensis" strains from Europe.
  • 2015
  • Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 53:10, s. 3126-3132
  • Tidskriftsartikel (refereegranskat)abstract
    • CandidatusNeoehrlichia mikurensis is the tick-borne agent of neoehrlichiosis, an infectious disease that primarily affects immunocompromised patients. So far, the genetic variability of Neoehrlichia has been studied only by comparing 16S rRNA gene and groEL operon sequences. We describe the development and use of a multi-locus sequence analysis (MLSA) protocol to characterize the genetic diversity of clinicalNeoehrlichiastrains in Europe and their relatedness to other species within the Anaplasmataceae family.Six genes were selected:ftsZ, clpB, gatB,lipA,groEL and 16SrRNA. Each MLSA locus was amplified by real-time PCR, and the PCR-products sequenced. Phylogenetic trees of MLSA locus relatedness were constructed from aligned sequences. Blood samples from 12 patients with confirmed Neoehrlichia infection from Sweden (n = 9), the Czech Republic (n = 2) and Germany (n = 1) were analyzed with the MLSA protocol.Threeof the Swedish strains exhibited identical lipA sequences, while the lipA sequences of the strains from the other nine patients were identical to each other.One of the Czech strains had one differing nucleotide in the clpB sequence from the sequences of the other 11 strains. All 12 strains had identical sequences for the genes 16SrRNA,ftsZ, gatB, and groEL.According to the MLSA, Neoehrlichia is most closely related to E. ruminantium, less so to A. phagocytophilum and least to Wolbachiaendosymbiont, among the Anaplasmataceae.To conclude, three sequence types of infectious Neoehrlichia wereidentified: one in the west of Sweden, one in the Czech Republic, and one spread throughout Europe.
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39.
  • Grankvist, Anna, et al. (författare)
  • Multilocus sequence analysis of clinical "candidatus neoehrlichia mikurensis" strains from Europe
  • 2015
  • Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 53:10, s. 3126-3132
  • Tidskriftsartikel (refereegranskat)abstract
    • Copyright © 2015, American Society for Microbiology. All Rights Reserved. Candidatus Neoehrlichia mikurensis" is the tick-borne agent of neoehrlichiosis, an infectious disease that primarily affects immunocompromised patients. So far, the genetic variability of "Ca. Neoehrlichia" has been studied only by comparing 16S rRNA genes and groEL operon sequences. We describe the development and use of a multilocus sequence analysis (MLSA) protocol to characterize the genetic diversity of clinical "Ca. Neoehrlichia" strains in Europe and their relatedness to other species within the Anaplasmataceae family. Six genes were selected: ftsZ, clpB, gatB, lipA, groEL, and 16S rRNA. Each MLSA locus was amplified by real-time PCR, and the PCR products were sequenced. Phylogenetic trees of MLSA locus relatedness were constructed from aligned sequences. Blood samples from 12 patients with confirmed "Ca. Neoehrlichia" infection from Sweden (n9), the Czech Republic (n2), and Germany (n1) were analyzed with the MLSA protocol. Three of the Swedish strains exhibited identical lipA sequences, while the lipA sequences of the strains from the other nine patients were identical to each other. One of the Czech strains had one differing nucleotide in the clpB sequence from the sequences of the other 11 strains. All 12 strains had identical sequences for the genes 16S rRNA, ftsZ, gatB, and groEL. According to the MLSA, among the Anaplasmataceae, "Ca. Neoehrlichia" is most closely related to Ehrlichia ruminantium, less so to Anaplasma phagocytophilum, and least to Wolbachia endosymbionts. To conclude, three sequence types of infectious "Ca. Neoehrlichia" were identified: one in the west of Sweden, one in the Czech Republic, and one spread throughout Europe.
  •  
40.
  • Grevskott, D. H., et al. (författare)
  • Complete sequence of a new conjugative multidrug-resistance encoding IncFII/IncFIA/IncFIB plasmid carrying NDM-6 metallo-beta-lactamase from pathogenic Escherichia coli sequence type 167 isolated from sewage in Norway
  • 2023
  • Ingår i: Journal of Global Antimicrobial Resistance. - 2213-7165. ; 33, s. 291-293
  • Tidskriftsartikel (refereegranskat)abstract
    • Objectives: The aim of the current study was to determine the genomic map of resistance genes and to understand the potential for mobility of a new NDM-6-carrying plasmid from a pathogenic Escherichia coli strain. A complete and closed genome sequence of the E. coli strain was obtained by applying a combination of short-read Illumina and long-read Nanopore-based sequencing.Methods: Isolation of E. coli was performed, using ECC CHROMagarTM, and antibiotic sensitivity pat-terns were determined, using SensititreTM EUVSEC3 plates. Whole-genome sequencing was performed, using Illumina MiSeq-and Oxford Nanopore MinION-based sequencing. Conjugation experiments were performed, using filter-mating and a green fluorescent protein (GFP)-tagged E. coli strain.Results: Two carbapenem-resistant E. coli strains were isolated from sewage. These strains (2-331 and 2-333) belonged to sequence type (ST) 167 and carried an NDM-6 carbapenemase. The complete genome of strain 2-331 (GenBank accession no.: CP110117-22.1) was assembled into six contigs, representing a complete circular chromosome of 4 947 178 bp and five plasmids, ranging from 143 596 bp to 1549 bp. Plasmid p2-331_1 ( similar to 144 kb), belonging to the IncFII/IncFIA/IncFIB group, carried multiple antibiotic resistance genes, including mph(A), mrx(A), blaTEM-1, rmtB1, blaNDM-6, ble, sul1, qacEA1, aadAA, dfrA12, and tet(A). Plasmid p2-331_1 was transferred from strain 2-331, via conjugation, conferring resistance against eight different classes of antibiotics to a GFP-tagged E. coli strain.Conclusions: Our study showed the emergence of a new conjugative plasmid-carrying NDM-6 carbapen-emase from pathogenic E. coli ST167 for the first time in Norway. The importance of population-based sewage-surveillance for understanding the antimicrobial resistance situation within the community is highlighted.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )
  •  
41.
  • Grevskott, D. H., et al. (författare)
  • Emergence and dissemination of epidemic-causing OXA-244 carbapenemase-producing Escherichia coli ST38 through hospital sewage in Norway, 2020-2022
  • 2024
  • Ingår i: JOURNAL OF HOSPITAL INFECTION. - 0195-6701 .- 1532-2939. ; 145, s. 165-173
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Population -based sewage surveillance has emerged as a promising approach for studying the prevalence of antibiotic resistance in pathogens. Aim: To determine the temporal prevalence of cefotaxime-resistant Escherichia coli in sewage from five sewage treatment plants located in Bergen city, to determine whether ESBL- and carbapenemase-producing E. coli are consistently disseminated in the receiving environment through sewage. Method: A total of 569 cefotaxime-resistant E. coli were isolated over a period of 19 months (August 2020 to February 2022) using ECC CHROMagarTM plates from 82 samples, antibiotic sensitivity profiles were determined, using SensititreTM plates. The draft genome sequences were determined, using Illumina MiSeq-based sequencing. Complete genome sequences were determined, using Oxford Nanopore-based sequencing. Findings: All 569 strains obtained from influent (N1/4461) and effluent (N1/4108) were multidrug resistant. Most of the sequenced strains (52 of 61) carried blaCTX-M-15 (38.5%) and blaCTX-M-27 (34.6%). The most prevalent sequence types (STs) for ESBL-carrying strains were ST131 (32.8%) and ST38 (21.3%). All CTX-M-27-carrying ST131 strains belonged to clade A or C1, while CTX-M-15-harbouring strains were present in all the clades. Five OXA-244producing ST38 strains, genetically similar to epidemic -causing strains from Western Norway, France and the Netherlands, were isolated only from raw and treated sewage of the treatment plant receiving hospital sewage.
  •  
42.
  • Grevskott, D. H., et al. (författare)
  • Nanopore sequencing reveals genomic map of CTX-M-type extended-spectrum β-lactamases carried by Escherichia coli strains isolated from blue mussels (Mytilus edulis) in Norway
  • 2020
  • Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 20:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Environmental surveillance of antibiotic resistance can contribute towards better understanding and management of human and environmental health. This study applied a combination of long-read Oxford Nanopore MinION and short-read Illumina MiSeq-based sequencing to obtain closed complete genome sequences of two CTX-M-producing multidrug-resistant Escherichia coli strains isolated from blue mussels (Mytilus edulis) in Norway, in order to understand the potential for mobility of the detected antibiotic resistance genes (ARGs). Results: The complete genome sequence of strain 631 (E. coli sequence type 38) was assembled into a circular chromosome of 5.19 Mb and five plasmids (between 98 kb and 5 kb). The majority of ARGs cluster in close proximity to each other on the chromosome within two separate multidrug-resistance determining regions (MDRs), each flanked by IS26 transposases. MDR-1 carries bla TEM-1, tmrB, aac(3)-IId, aadA5, mph(A), mrx, sul1, qacEΔ1 and dfrA17; while MDR-2 harbors aph(3″)-Ib, aph(6)-Id, bla TEM-1, catA1, tet(D) and sul2. Four identical chromosomal copies of bla CTX-M-14 are located outside these regions, flanked by ISEc9 transposases. Strain 1500 (E. coli sequence type 191) exhibited a circular chromosome of 4.73 Mb and two plasmids (91 kb and 4 kb). The 91 kb conjugative plasmid belonging to IncI1 group carries bla CTX-M-15 and bla TEM-1 genes. Conclusion: This study confirms the efficacy of combining Nanopore long-read and Illumina short-read sequencing for determining complete bacterial genome sequences, enabling detection and characterization of clinically important ARGs in the marine environment in Norway, with potential for further dissemination. It also highlights the need for environmental surveillance of antibiotic resistance in low prevalence settings like Norway. © 2020 The Author(s).
  •  
43.
  • Hedberg, Maria E, et al. (författare)
  • Lachnoanaerobaculum gen. nov., a new genus in the Lachnospiraceae: characterization of Lachnoanaerobaculum umeaense gen. nov., sp. nov., isolated from the human small intestine, and Lachnoanaerobaculum orale sp. nov., isolated from saliva, and reclassification of Eubacterium saburreum (Prevot 1966) Holdeman and Moore 1970 as Lachnoanaerobaculum saburreum comb. nov.
  • 2012
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 62:Pt 11, s. 2685-90
  • Tidskriftsartikel (refereegranskat)abstract
    • Two novel obligately anaerobic, Gram-stain-positive, saccharolytic and non-proteolytic spore-forming bacilli (strains CD3:22(T) and N1(T)) are described. Strain CD3:22(T) was isolated from a biopsy of the small intestine of a child with coeliac disease, and strain N1(T) from the saliva of a healthy young man. The cells of both strains were observed to be filamentous, approximately 5 to >20 µm long, some of them curving and with swellings. The novel organisms produced H(2)S, NH(3), butyric acid and acetic acid as major metabolic end products. Phylogenetic analyses, based on comparative 16S rRNA gene sequencing, revealed close relationships (98% sequence similarity) between the two isolates, as well as the type strain of Eubacterium saburreum and four other Lachnospiraceae bacterium-/E. saburreum-like organisms. This group of bacteria were clearly different from any of the 19 known genera in the family Lachnospiraceae. While Eubacterium species are reported to be non-spore-forming, reanalysis of E. saburreum CCUG 28089(T) confirmed that the bacterium is indeed able to form spores. Based on 16S rRNA gene sequencing, phenotypic and biochemical properties, strains CD3:22(T) and N1(T) represent novel species of a new and distinct genus, named Lachnoanaerobaculum gen. nov., in the family Lachnospiraceae [within the order Clostridiales, class Clostridia, phylum Firmicutes]. Strain CD3:22(T) (=CCUG 58757(T) =DSM 23576(T)) is the type strain of the type species, Lachnoanaerobaculum umeaense gen. nov., sp. nov., of the proposed new genus. Strain N1(T) (=CCUG 60305(T)=DSM 24553(T)) is the type strain of Lachnoanaerobaculum orale sp. nov. Moreover, Eubacterium saburreum is reclassified as Lachnoanaerobaculum saburreum comb. nov. (type strain CCUG 28089(T) =ATCC 33271(T) =CIP 105341(T) =DSM 3986(T) =JCM 11021(T) =VPI 11763(T)).
  •  
44.
  • Hedberg, Maria E., et al. (författare)
  • Prevotella jejuni sp. nov., isolated from the small intestine of a child with celiac disease.
  • 2013
  • Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 63:11, s. 4218-4223
  • Tidskriftsartikel (refereegranskat)abstract
    • Five obligately anaerobic, Gram-negative, saccharolytic and proteolytic, non-spore-forming bacilli (CD3:27, CD3:28T, CD3:33, CD3:32 and CD3:34) are described. All five strains were isolated from the small intestine of a female child with celiac disease. The cells of the five strains were observed to be short rods or coccoid cells with longer filamentous forms seen sporadically. The organisms produced acetic acid and succinic acid as major metabolic end products. Phylogenetic analysis, based on comparative 16S rRNA gene sequence analysis revealed close relationships between CD3:27, CD3:28T and CD3:33 on one hand, between CD3:32 and P. histicola CCUG 55407T and between CD3:34 and P. melaninogenica CCUG 4944BT on the other. The strains CD3:27, CD3:28T and CD3:33 were clearly different from any other species within the genus Prevotella and most closely related to but distinct from P. melaninogenica. Based on 16S rRNA gene, RNA polymerase β-subunit gene and 60-kDa chaperonin protein subunit gene sequencing, phenotypic, chemical and biochemical properties strains CD3:27, CD3:28T and CD3:33 have been determined to represent a novel species within the genus Prevotella, named Prevotella jejuni sp. nov. Strain CD3:28T (CCUG 60371T = DSM 26989T) is the type strain of the proposed new species. All five strains were able to form homologous aggregates, in which tube-like structures were connecting individual bacteria cells. The five strains were able to bind to human intestinal carcinoma cell lines at 37 °C.
  •  
45.
  • Helldal, Lisa, et al. (författare)
  • Evaluation of MLVA for epidemiological typing and outbreak detection of ESBL-producing Escherichia coli in Sweden
  • 2017
  • Ingår i: Bmc Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 17
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: To identify the spread of nosocomial infections and halt outbreak development caused by Escherichia coli that carry multiple antibiotic resistance factors, such as extended-spectrum beta-lactamases (ESBLs) and carbapenemases, is becoming demanding challenges due to the rapid global increase and constant and increasing influx of these bacteria from the community to the hospital setting. Our aim was to assess a reliable and rapid typing protocol for ESBL-E. coli, with the primary focus to screen for possible clonal relatedness between isolates. All clinical ESBL-E. coli isolates, collected from hospitals (n = 63) and the community (n = 41), within a single geographical region over a 6 months period, were included, as well as clinical isolates from a polyclonal outbreak (ST131, n = 9, and ST1444, n = 3). The sporadic cases represented 36 STs, of which eight STs dominated i.e. ST131 (n = 33 isolates), ST648 (n = 10), ST38 (n = 9), ST12 and 69 (each n = 4), ST 167, 405 and 372 (each n = 3). The efficacy of multiple-locus variable number tandem repeat analysis (MLVA) was evaluated using three, seven or ten loci, in comparison with that of pulsed-field gel electrophoresis (PFGE) and multi locus sequence typing (MLST). Results: MLVA detected 39, 55 and 60 distinct types, respectively, using three (GECM-3), seven (GECM-7) or ten (GECM-10) loci. For GECM-7 and -10, 26 STs included one type and eleven STs each included several types, the corresponding numbers for GECM-3 were 29 and 8. The highest numbers were seen for ST131 (7,7 and 8 types, respectively), ST38 (5,5,8) and ST648 (4,5,5). Good concordance was observed with PFGE and GECM-7 and -10, despite fewer types being identified with MLVA; 78 as compared to 55 and 60 types. The lower discriminatory power of MLVA was primarily seen within the O25b-ST131 lineage (n = 34) and its H30-Rx subclone (n = 21). Epidemiologically unrelated O25b-ST131 isolates were clustered with O25b-ST131 outbreak isolates by MLVA, whereas the ST1444 outbreak isolates were accurately distinguished from unrelated isolates. Conclusion: MLVA, even when using only three loci, represents an easy initial typing tool for epidemiological screening of ESBL-E. coli. For the ST131-O25b linage, complementary methods may be needed to obtain sufficient resolution.
  •  
46.
  • Helldal, Lisa, et al. (författare)
  • Increasing prevalence of ESBL but not AmpC in Escherichia coli and Klebsiella pneumoniae, in Göteborg, 2004-2008
  • 2009
  • Ingår i: Scandinavian Society for Antimicrobial Chemotherapy - 2009, September 3, Tromsø, Norway.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Introduction: The increasing prevalence of transferable broad-spectrum resistance to beta-lactams, such as Extended Spectrum Beta Lactamases (ESBL) and AmpC, is troublesome, since they confer resistance to cephalosporins and penicillins, and often also are associated with additional resistance. Materials and methods: Resistance for E. coli and Klebsiella pneumoniae isolated from urine (~10.000 isolates/year) and blood (~xxx isolates/year), during 2004-2008 were determined. Cephalosporin resistant isolates were examined for presence of ESBL with a double-disk-assay using clavulanic acid as inhibitory substance. Cefoxitine-resistant strains were analyzed for presence of AmpC with a second double-disk-assay using cloxacillin as inhibitory substance. Positive strains where further tested with PCR assays for ESBL and plasmid AmpC. Results: During 2004-2008 presence of ESBL increased from 0,3–1,5% in urinary and 0,0–1,4 % in blood E. coli. For Klebsiella the corresponding figures were 0,08–0,68% and 0%, respectively. For ESBL-producing E. coli, 60–80% were resistant also to quinolones and trimetoprime. In 2008, the vast a majority of the ESBL-isolates carried CTX-M subtype 1. Approximately 50 % is community-acquired isolates. 0,15-0,23% of the urinary E. coli-strains had phenotypical characteristics indicating AmpC-production. Presence of plasmid-mediated AmpC will be tested. Approximately 50% of these were multidrug resistant. In blood E coli isolates as well as in Klebsiella from urine and blood AmpC was rarely detected (0-2 isolates/year). Discussion and Conclusion: There is a steady increase in ESBL-producing bacteria in our region. However, the frequency of isolates with AmpC is still low. In addition, a majority of these strains are multidrug resistant which is particularly alarming.
  •  
47.
  • Helldal, Lisa, et al. (författare)
  • Shift of CTX-M genotypes has determined the increased prevalence of extended-spectrum beta-lactamase-producing Escherichia coli in south-western Sweden
  • 2013
  • Ingår i: Clinical Microbiology and Infection. - : Elsevier BV. - 1198-743X .- 1469-0691. ; 19:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The prevalence of Escherichia coli producing extended-spectrum β-lactamases (ESBLs) markedly increased during 2004-2008 in south-western Sweden, with a greater increase in urinary isolates in hospitals (0.2-2.5%) than in the community (0.2-1.6%). ESBLs of genotype CTX-M predominated, with a significant (p<0.02) shift from the CTX-M-9 to CTX-M-1 phylogroup occurring among urinary ESBL-producing E.coli isolated early (n=41) as compared with late (n=221) in the study period. The increase in ESBL-producing E.coli was polyclonal, and only partly attributable to an increase (0-24%) in the number of O25b-ST131 isolates carrying CTX-M-15. The increase was prominent in men and in elderly patients, and warrants continued surveillance.
  •  
48.
  • Helldal, Lisa, et al. (författare)
  • Shifts in Extended-Spectrum Beta-Lactamase types with increasing prevalence of Escherichia coli producing ESBL
  • 2010
  • Ingår i: 20th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), Vienna, Austria.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Objectives: Contrary to other multidrug-resistant pathogens, the prevalence of bacteria producing extended-spectrum beta-lactamase (ESBL) is increasing rapidly in Sweden. In Europe, ESBL of CTX-M-, TEM-, OXA- and SHV-types are generally associated with E. coli infections, CTX-M being the most predominant. We have investigated how the prevalence of these types has changed during the last five years in the low endemic setting of western Sweden. Methods: Yearly resistance in urinary (approximately 10,000 isolates/year) and blood (approximately 250 isolates/year) E. coli during 2004-2008 were determined. Cephalosporin-resistant isolates were screened for ESBL, using a double-disk assay with clavulanic acid as the inhibitory agent. All ESBL-E. coli isolated in the region during the periods Sept 2003-April 2005 (n=46) and April 2008-March 2009 (n=256) were typed by multiplex-PCR, detecting CTX-M, TEM, OXA and SHV. CTX-M-positive isolates were sub-typed by real time Q-PCR for CTX-M-1, CTX-M-2 and CTXM-9 groups. Results: During 2004-2008, ESBL-producing E. coli strains increased from 0.3-1.5% in urinary and 0-1.4% in blood isolates. Resistance to quinolones and trimethoprim was observed in 60-80% of strains, as compared to less than 8% in non-ESBL-producing E. coli. The majority of the ESBL-E. coli strains possessed the CTX-M gene-type, increasing from 78% (36/46) in 2003-2005 to 93% (238/256) in 2008-2009. Between these time-periods, a marked shift occurred in the distribution of CTX-M types, in that strains with the CTX-M-9 group decreased from 42% (15/36) of isolates to 21% (51/238, p=0.01) and, simultaneously, strains with the CTX-M-1 group increased from 58% (21/36) to 78% (185/238, p= 0.02). Furthermore, strains of CTX-M-type exhibiting also TEM- and/or OXA increased to comprise 86% of cases, as compared to 75% previously. Similar trends were seen for community and hospital detected isolates and with no differences associated with age in affected patients. Conclusion: A steady increase in multidrug-resistant ESBL-E. coli, possessing the genes for multiple ESBL-types, was observed in western Sweden, contrary to the patterns of other multidrug-resistant bacteria. As ESBL has increased during the five-year study period, we detected a shift in the prevalence of ESBL-types, currently dominated by the CTX-M-1 group. These observations suggest that a novel ESBL-producing E. coli clone may have emerged in the area, which will be further investigated and presented.
  •  
49.
  • Hernández, Marcela, et al. (författare)
  • Isolation and characterisation of a novel simazine-degrading bacterium from agricultural soil of central Chile, Pseudomonas nitroreducens MHP41
  • 2009
  • Ingår i: FEMS 2009 - 3rd Congress of European Microbiologists.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Background: s-Triazine herbicides, such as simazine, are used in America in agriculture and forestry. This herbicide is persistent in soils, as well as in aquifers. Chemical and biological processes are involved in the dissipation of simazine in soil. However, microbial degradation is probably the main mechanism for removing s-triazine from soils. Objectives: 1. Isolation, metabolic and systematic characterization of bacterium MHP41 from herbicide-contaminated agricultural soil in Chile. Methods: Bacterial strains were isolated by enrichment in minimal medium with simazine as the sole nitrogen source. Simazine degradation was analysed by resting cell assays and analyses of atz genes were assessed by PCR and DNA sequencing. Strain MHP41 was characterised by ARDRA, using restriction endonucleases, MspI and HhaI, phenotypic characterisation, cell fatty acid profiling and multi-locus sequence analysis (MLSA), using 16S rRNA gene, IGS-1, gyrB and rpoB sequencing. Results: 1. Strain MHP41 grew in minimal medium, using simazine as the sole source of nitrogen. 2. Resting cells of strain MHP41 degraded more than 80% of simazine within 60 min. 3. The atzA, atzB, atzC, atzD, atzE and atzF degradation genes were detected by PCR and characterised by sequence analysis. 4. Strain MHP41 was identified initially as a Pseudomonas sp. and comparative MLSA determined MHP41 to be a strain of P. nitroreducens. Conclusions: 1. The isolation and characterization of a simazine-degrading bacterium MHP41, which is capable of growing with simazine as the sole nitrogen source. 2. P. nitroreducens MHP41 possesses all atz genes of the upper and lower catabolic pathways for simazine degradation. 4. MHP41 is the first known strain of P. nitroreducens capable of degrading simazine and represents an interesting bacterium for studies on the bioremediation of s-triazine-contaminated soils.
  •  
50.
  • Hernandez, Marcela, et al. (författare)
  • Isolation and characterization of a novel simazine-degrading bacterium from agricultural soil of central Chile, Pseudomonas sp MHP41
  • 2008
  • Ingår i: Fems Microbiology Letters. - : Oxford University Press (OUP). - 0378-1097 .- 1574-6968. ; 286:2, s. 184-190
  • Tidskriftsartikel (refereegranskat)abstract
    • s-Triazine herbicides are used extensively in South America in agriculture and forestry. In this study, a bacterium designated as strain MHP41, capable of degrading simazine and atrazine, was isolated from agricultural soil in the Quillota valley, central Chile. Strain MHP41 is able to grow in minimal medium, using simazine as the sole nitrogen source. In this medium, the bacterium exhibited a growth rate of μ=0.10 h−1, yielding a high biomass of 4.2 × 108 CFU mL−1. Resting cells of strain MHP41 degrade more than 80% of simazine within 60 min. The atzA, atzB, atzC, atzD, atzE and atzF genes encoding the enzymes of the simazine upper and lower pathways were detected in strain MHP41. The motile Gram-negative bacterium was identified as a Pseudomonas sp., based on the Biolog microplate system and comparative sequence analyses of the 16S rRNA gene. Amplified ribosomal DNA restriction analysis allowed the differentiation of strain MHP41 from Pseudomonas sp. ADP. The comparative 16S rRNA gene sequence analyses suggested that strain MHP41 is closely related to Pseudomonas nitroreducens and Pseudomonas multiresinovorans. This is the first s-triazine-degrading bacterium isolated in South America. Strain MHP41 is a potential biocatalyst for the remediation of s-triazine-contaminated environments.
  •  
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