| 1. |
- Jakobsson, Hedvig E, et al.
(författare)
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The composition of the gut microbiota shapes the colon mucus barrier.
- 2015
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Ingår i: EMBO reports. - : EMBO. - 1469-3178 .- 1469-221X. ; 16, s. 164-177
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Tidskriftsartikel (refereegranskat)abstract
- Two C57BL/6 mice colonies maintained in two rooms of the same specific pathogen-free (SPF) facility were found to have different gut microbiota and a mucus phenotype that was specific for each colony. The thickness and growth of the colon mucus were similar in the two colonies. However, one colony had mucus that was impenetrable to bacteria or beads the size of bacteria-which is comparable to what we observed in free-living wild mice-whereas the other colony had an inner mucus layer penetrable to bacteria and beads. The different properties of the mucus depended on the microbiota, as they were transmissible by transfer of caecal microbiota to germ-free mice. Mice with an impenetrable mucus layer had increased amounts of Erysipelotrichi, whereas mice with a penetrable mucus layer had higher levels of Proteobacteria and TM7 bacteria in the distal colon mucus. Thus, our study shows that bacteria and their community structure affect mucus barrier properties in ways that can have implications for health and disease. It also highlights that genetically identical animals housed in the same facility can have rather distinct microbiotas and barrier structures.
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| 2. |
- Johansson, Malin E V, 1971, et al.
(författare)
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Normalization of Host Intestinal Mucus Layers Requires Long-Term Microbial Colonization
- 2015
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Ingår i: Cell Host & Microbe. - : Elsevier BV. - 1931-3128 .- 1934-6069. ; 18:5, s. 582-592
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Tidskriftsartikel (refereegranskat)abstract
- The intestinal mucus layer provides a barrier limiting bacterial contact with the underlying epithelium. Mucus structure is shaped by intestinal location and the microbiota. To understand how commensals modulate gut mucus, we examined mucus properties under germ-free (GF) conditions and during microbial colonization. Although the colon mucus organization of GF mice was similar to that of conventionally raised (Convr) mice, the GF inner mucus layer was penetrable to bacteria-sized beads. During colonization, in which GF mice were gavaged with Convr microbiota, the small intestine mucus required 5 weeks to be normally detached and colonic inner mucus 6 weeks to become impenetrable. The composition of the small intestinal microbiota during colonization was similar to Convr donors until 3 weeks, when Bacteroides increased, Firmicutes decreased, and segmented filamentous bacteria became undetectable. These findings highlight the dynamics of mucus layer development and indicate that studies of mature microbe-mucus interactions should be conducted weeks after colonization.
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| 3. |
- Salvà-Serra, Francisco, 1989, et al.
(författare)
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Complete genome sequences of Streptococcus pyogenes type strain reveal 100%-match between PacBio-solo and Illumina-Oxford Nanopore hybrid assemblies
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- We present the first complete, closed genome sequences of Streptococcus pyogenes strains NCTC 8198(T) and CCUG 4207(T), the type strain of the type species of the genus Streptococcus and an important human pathogen that causes a wide range of infectious diseases. S. pyogenes NCTC 8198(T) and CCUG 4207(T) are derived from deposit of the same strain at two different culture collections. NCTC 8198(T) was sequenced, using a PacBio platform; the genome sequence was assembled de novo, using HGAP. CCUG 4207(T) was sequenced and a de novo hybrid assembly was generated, using SPAdes, combining Illumina and Oxford Nanopore sequence reads. Both strategies yielded closed genome sequences of 1,914,862 bp, identical in length and sequence identity. Combining short-read Illumina and long-read Oxford Nanopore sequence data circumvented the expected error rate of the nanopore sequencing technology, producing a genome sequence indistinguishable to the one determined with PacBio. Sequence analyses revealed five prophage regions, a CRISPR-Cas system, numerous virulence factors and no relevant antibiotic resistance genes. These two complete genome sequences of the type strain of S. pyogenes will effectively serve as valuable taxonomic and genomic references for infectious disease diagnostics, as well as references for future studies and applications within the genus Streptococcus.
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| 4. |
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| 5. |
- Abrahamsson, Thomas, et al.
(författare)
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Low diversity of the gut microbiota in infants with atopic eczema
- 2012
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Ingår i: Journal of Allergy and Clinical Immunology. - New York, USA : Elsevier BV. - 0091-6749 .- 1097-6825. ; 129:2, s. 434-U244
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: It is debated whether a low total diversity of the gut microbiota in early childhood is more important than an altered prevalence of particular bacterial species for the increasing incidence of allergic disease. The advent of powerful, cultivation-free molecular methods makes it possible to characterize the total microbiome down to the genus level in large cohorts. OBJECTIVE: We sought to assess microbial diversity and characterize the dominant bacteria in stool during the first year of life in relation to atopic eczema development. METHODS: Microbial diversity and composition were analyzed with barcoded 16S rDNA 454-pyrosequencing in stool samples at 1 week, 1 month, and 12 months of age in 20 infants with IgE-associated eczema and 20 infants without any allergic manifestation until 2 years of age (ClinicalTrials.gov ID NCT01285830). RESULTS: Infants with IgE-associated eczema had a lower diversity of the total microbiota at 1 month (P= .004) and a lower diversity of the bacterial phylum Bacteroidetes and the genus Bacteroides at 1 month (P= .02 and P= .01) and the phylum Proteobacteria at 12 months of age (P= .02). The microbiota was less uniform at 1 month than at 12 months of age, with a high interindividual variability. At 12 months, when the microbiota had stabilized, Proteobacteria, comprising gram-negative organisms, were more abundant in infants without allergic manifestation (Empirical Analysis of Digital Gene Expression in R edgeR test: P= .008, q= 0.02). CONCLUSION: Low intestinal microbial diversity during the first month of life was associated with subsequent atopic eczema.
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| 6. |
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| 7. |
- Gonzales-Siles, Lucia, et al.
(författare)
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Mass Spectrometry Proteotyping of Streptococcus pneumoniae and commensal Streptococcus: identification of biomarkers for infectious strain characterization
- 2016
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Ingår i: 26th ECCMID 2016 Amsterdam, The Netherlands. 9 - 12 April 2016.
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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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| 8. |
- Hugerth, Luisa W., et al.
(författare)
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DegePrime, a Program for Degenerate Primer Design for Broad-Taxonomic-Range PCR in Microbial Ecology Studies
- 2014
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 80:16, s. 5116-5123
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Tidskriftsartikel (refereegranskat)abstract
- The taxonomic composition of a microbial community can be deduced by analyzing its rRNA gene content by, e. g., high-throughput DNA sequencing or DNA chips. Such methods typically are based on PCR amplification of rRNA gene sequences using broad-taxonomic-range PCR primers. In these analyses, the use of optimal primers is crucial for achieving an unbiased representation of community composition. Here, we present the computer program DegePrime that, for each position of a multiple sequence alignment, finds a degenerate oligomer of as high coverage as possible and outputs its coverage among taxonomic divisions. We show that our novel heuristic, which we call weighted randomized combination, performs better than previously described algorithms for solving the maximum coverage degenerate primer design problem. We previously used DegePrime to design a broad-taxonomic-range primer pair that targets the bacterial V3-V4 region (341F-805R) (D. P. Herlemann, M. Labrenz, K. Jurgens, S. Bertilsson, J. J. Waniek, and A. F. Andersson, ISME J. 5:1571-1579, 2011, http://dx.doi.org/10.1038/ismej.2011.41), and here we use the program to significantly increase the coverage of a primer pair (515F-806R) widely used for Illumina-based surveys of bacterial and archaeal diversity. By comparison with shotgun metagenomics, we show that the primers give an accurate representation of microbial diversity in natural samples.
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| 9. |
- Jakobsson, Hedvig E., et al.
(författare)
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Decreased gut microbiota diversity, delayed Bacteroidetes colonisation and reduced Th1 responses in infants delivered by Caesarean section
- 2014
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Ingår i: Gut. - London : BMJ. - 0017-5749 .- 1468-3288. ; 63:4, s. 559-566
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Tidskriftsartikel (refereegranskat)abstract
- important stimuli for immune development, and a reduced microbial exposure as well as caesarean section (CS) has been associated with the development of allergic disease. Here we address how microbiota development in infants is affected by mode of delivery, and relate differences in colonisation patterns to the maturation of a balanced Th1/Th2 immune response. Design The postnatal intestinal colonisation pattern was investigated in 24 infants, born vaginally (15) or by CS (nine). The intestinal microbiota were characterised using pyrosequencing of 16S rRNA genes at 1 week and 1, 3, 6, 12 and 24 months after birth. Venous blood levels of Th1- and Th2-associated chemokines were measured at 6, 12 and 24 months. Results Infants born through CS had lower total microbiota diversity during the first 2 years of life. CS delivered infants also had a lower abundance and diversity of the Bacteroidetes phylum and were less often colonised with the Bacteroidetes phylum. Infants born through CS had significantly lower levels of the Th1-associated chemokines CXCL10 and CXCL11 in blood. Conclusions CS was associated with a lower total microbial diversity, delayed colonisation of the Bacteroidetes phylum and reduced Th1 responses during the first 2 years of life.
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| 10. |
- Jakobsson, Hedvig E, et al.
(författare)
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Draft Genome Sequence of Moraxella catarrhalis Type Strain CCUG 353T.
- 2016
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Ingår i: Genome Announcements. - 2169-8287. ; 4:3
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Tidskriftsartikel (refereegranskat)abstract
- Moraxella catarrhalis is a Gram-negative commensal and pathogenic bacterium found in the human respiratory tract. It is associated with otitis media and respiratory tract infections. Here, we report the draft genome sequence of M. catarrhalis type strain CCUG 353(T), composed of 18 contigs and a total size of 1.89 Mb.
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| 11. |
- Jakobsson, Hedvig E, et al.
(författare)
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Draft Genome Sequences of Six Strains of Streptococcus pneumoniae from Serotypes 5, 6A, 6B, 18C, 19A, and 23F
- 2017
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Ingår i: Genome Announcements. - 2169-8287. ; 5:14
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Tidskriftsartikel (refereegranskat)abstract
- Streptococcus pneumoniae is a pathogenic bacterium found most commonly in the respiratory tract of humans and is a common cause of pneumonia and bacterial meningitis. Here, we report the draft genome sequences of six S. pneumoniae strains: CCUG 1350, CCUG 7206, CCUG 11780, CCUG 33774, CCUG 35180, and CCUG 35272.
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| 12. |
- Jakobsson, Hedvig E, et al.
(författare)
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Proteotyping of Streptococcus pneumoniae, using tandem mass spectrometry for identification of biomarkers for species and strain differentiation
- 2016
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Ingår i: 11th International Meeting on Microbial Epidemiological Markers (IMMEM XI) 9 - 12 March 2016, Estoril, Portugal. - : European Society for Clinical Microbiology and Infectious Diseases.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background. Streptococcus pneumoniae (pneumococcus) is the leading cause of community-acquired pneumonia and a major cause of morbidity and mortality worldwide. S. pneumoniae is phenotypically and genotypically similar to commensal species of the upper respiratory tract of the Streptococcus mitis-Group (viridans streptococci), S. mitis, S. oralis, and S. pseudopneumoniae, causing problems of identification in clinical microbiology laboratories. We have applied state-of-the-art proteomics techniques for Streptococcus spp. proteotyping; to detecting and characterizing expressed protein biomarkers for species-level identification, determination of antibiotic resistance and virulence biomarkers and strain typing for epidemiological analyses. Material and methods. The proteins of intact bacteria or cell fractions are bound to a membrane surface, using patented (WO2006068619) Lipid-based Protein Immobilization (LPITM) technology. Peptides are generated from the bound proteins, using enzymatic digestion, separated and analyzed, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The mass spectra profiles are compared to a database of reference peptide sequences. Subsequently, the identified peptides are compared to a database of reference genome sequences, all complete genomes of the NCBI Reference Sequence (RefSeq) Database. In this study, the type strains of the close-related mitis complex species S. pneumoniae (CCUG 28588T), S. mitis (CCUG 31611T), S. oralis (CCUG 13229T), S. psedopneumoniae (CCUG 49455T) and the more distantly-related S. pyogenes (CCUG 4207T) were analysed individually and in mixtures, to demonstrate proteotyping capability and differentiate closely related species,. Additionally, mixes containing different S. pneumoniae strains were analyzed. Results. Using proteotyping protocols, it was possible to detect and correctly identify S. pneumoniae from the closely related bacterial species, S. mitis, S. oralis S. psedopneumoniae and S. pyogenes, as well as different strains of S. pneumoniae by identification of unique discriminatory peptides. For successful proteotyping,a comprehensive and accurate genomic database is the key to obtaining reliable proteotyping data. Importantly, because of questionable classifications of sequenced genomes in the public databases, before incorporation of reference genomic sequence data for proteotyping, the genome sequences should be verified and confirmed for accurate classifications. Furthermore, it is also essential to include all relevant species with as many as 25 genomes in order to obtain a comprehensive coverage of coding sequences for accurate peptide matching and to be able to discriminate between the most closely related species. In this study, all genomes of the S. mitis-Group in the database were analyzed, using Average Nucleotide Identity Blast (ANIb) and S. mitis-Group strains that cannot be identified to the species level, using standard genotypic and phenotypic approaches, where characterized by proteotyping and whole genome sequencing to describe their taxonomy and to improve the database matching. Conclusions: Proteotyping, using LC-MS/MS, enabled the differentiation and identification of pneumococcus from its closely related species and sub-species-level strain discrimination, all from single MS analyses. The whole method will enhance the identification and characterization of microorganisms, allowing high-resolution discrimination of closely related species through the confident identification of new biomarkers, ultimately for cultivation-independent application to the analyses of clinical samples.
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| 13. |
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| 14. |
- Karlsson, Roger, 1975, et al.
(författare)
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Discovery of Species-unique Peptide Biomarkers of Bacterial Pathogens by Tandem Mass Spectrometry-based Proteotyping
- 2020
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 19:3, s. 518-528
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Tidskriftsartikel (refereegranskat)abstract
- Mass spectrometry (MS) and proteomics offer comprehensive characterization and identification of microorganisms and discovery of protein biomarkers that are applicable for diagnostics of infectious diseases. The use of biomarkers for diagnostics is widely applied in the clinic and the use of peptide biomarkers is increasingly being investigated for applications in the clinical laboratory. Respiratory-tract infections are a predominant cause for medical treatment, although, clinical assessments and standard clinical laboratory protocols are time-consuming and often inadequate for reliable diagnoses. Novel methods, preferably applied directly to clinical samples, excluding cultivation steps, are needed to improve diagnostics of infectious diseases, provide adequate treatment and reduce the use of antibiotics and associated development of antibiotic resistance. This study applied nano-liquid chromatography (LC) coupled with tandem MS, with a bioinformatics pipeline and an in-house database of curated high-quality reference genome sequences to identify species-unique peptides as potential biomarkers for four bacterial pathogens commonly found in respiratory tract infections (RTIs): Staphylococcus aureus; Moraxella catarrhalis; Haemophilus influenzae and Streptococcus pneumoniae. The species-unique peptides were initially identified in pure cultures of bacterial reference strains, reflecting the genomic variation in the four species and, furthermore, in clinical respiratory tract samples, without prior cultivation, elucidating proteins expressed in clinical conditions of infection. For each of the four bacterial pathogens, the peptide biomarker candidates most predominantly found in clinical samples, are presented. Data are available via ProteomeXchange with identifier PXD014522. As proof-of-principle, the most promising species-unique peptides were applied in targeted tandem MS-analyses of clinical samples and their relevance for identifications of the pathogens, i.e. proteotyping, was validated, thus demonstrating their potential as peptide biomarker candidates for diagnostics of infectious diseases.
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| 15. |
- Karlsson, Roger, 1975, et al.
(författare)
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Proteotyping bacteria: Characterization, differentiation and identification of pneumococcus and other species within the Mitis Group of the genus Streptococcus by tandem mass spectrometry proteomics
- 2018
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- A range of methodologies may be used for analyzing bacteria, depending on the purpose and the level of resolution needed. The capability for recognition of species distinctions within the complex spectrum of bacterial diversity is necessary for progress in microbiological research. In clinical settings, accurate, rapid and cost-effective methods are essential for early and efficient treatment of infections. Characterization and identification of microorganisms, using, bottom-up proteomics, or "proteotyping", relies on recognition of species-unique or associated peptides, by tandem mass spectrometry analyses, dependent upon an accurate and comprehensive foundation of genome sequence data, allowing for differentiation of species, at amino acid-level resolution. In this study, the high resolution and accuracy of MS/MS-based proteotyping was demonstrated, through analyses of the three phylogenetically and taxonomically most closely-related species of the Mitis Group of the genus Streptococcus: i.e., the pathogenic species, Streptococcus pneumoniae (pneumococcus), and the commensal species, Streptococcus pseudopneumoniae and Streptococcus mitis. To achieve high accuracy, a genome sequence database used for matching peptides was created and carefully curated. Here, MS-based, bottom-up proteotyping was observed and confirmed to attain the level of resolution necessary for differentiating and identifying the most-closely related bacterial species, as demonstrated by analyses of species of the Streptococcus Mitis Group, even when S. pneumoniae were mixed with S. pseudopneumoniae and S. mitis, by matching and identifying more than 200 unique peptides for each species.
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| 16. |
- Marathe, Nachiket, et al.
(författare)
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Scandinavium goeteborgense gen. nov., sp. nov., a New Member of the Family Enterobacteriaceae Isolated From a Wound Infection, Carries a Novel Quinolone Resistance Gene Variant
- 2019
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 10:10
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Tidskriftsartikel (refereegranskat)abstract
- © Copyright © 2019 Marathe, Salvà-Serra, Karlsson, Larsson, Moore, Svensson-Stadler and Jakobsson. The family Enterobacteriaceae is a taxonomically diverse and widely distributed family containing many human commensal and pathogenic species that are known to carry transferable antibiotic resistance determinants. Characterization of novel taxa within this family is of great importance in order to understand the associated health risk and provide better treatment options. The aim of the present study was to characterize a Gram-negative bacterial strain (CCUG 66741) belonging to the family Enterobacteriaceae, isolated from a wound infection of an adult patient, in Sweden. Initial phenotypic and genotypic analyses identified the strain as a member of the family Enterobacteriaceae but could not assign it to any previously described species. The complete 16S rRNA gene sequence showed highest similarity (98.8%) to four species. Whole genome sequencing followed by in silico DNA-DNA similarity analysis and average nucleotide identity (ANI) analysis confirmed that strain CCUG 66741 represents a novel taxon. Sequence comparisons of six house-keeping genes (16S rRNA, atpD, dnaJ, gyrB, infB, rpoB) with those of the type strains of the type species of related genera within the family Enterobacteriaceae indicated that the strain embodies a novel species within the family. Phylogenomic analyses (ANI-based and core genome-based phylogeny) showed that strain CCUG 66741 forms a distinct clade, representing a novel species of a distinct, new genus within the family Enterobacteriaceae, for which the name Scandinavium goeteborgense gen. nov., sp. nov. is proposed, with CCUG 66741T as the type strain (= CECT 9823T = NCTC 14286T). S. goeteborgense CCUG 66741T carries a novel variant of a chromosomally-encoded quinolone resistance gene (proposed qnrB96). When expressed in Escherichia coli, the qnrB96 gene conferred five-fold increase in minimum inhibitory concentration against ciprofloxacin. This study highlights the importance and the utility of whole genome sequencing for pathogen identification in clinical settings.
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| 17. |
- Moore, Edward R.B. 1954, et al.
(författare)
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PROTEOTYPING: Tandem Mass Spectrometry Proteomics and Whole Genome Sequence-Based Diagnostics of Infectious Bacteria is Depedent upon a Reliable and Comprehensive Systematic Framework
- 2016
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Ingår i: Third Meeting on “Microbial Systematics and Metagenomics”. Bergey’s International Society for Microbial Systematics (BISMiS). September 12 - 15, 2016, Pune, India.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The global expansion of anti-microbial resistance (AMR) in bacteria, including human pathogens, presents major challenges for treatment and preventing the spread of infection. The World Health Organisation (WHO) has predicted the advent of infectious diseases for which no antibiotic treatment will be available [1]. With this outlook in the escalation of AMR, combined with continuing decline in new antibiotic discovery, development of innovative, reliable, rapid and costefficient analytical techniques for effective diagnostics and characterisations of infectious microorganisms is increasingly essential to prevent rising mortality and to reduce the costs associated with antibiotic-resistant infections. However, the routine methodologies used today for diagnosing infectious bacteria depend upon protocols that require prior cultivation from samples. Faced with patients exhibiting symptoms of infection, physicians typically resort to prescribing broad-spectrum antibiotics while they wait days or weeks for results from the laboratory. With increasing whole-genome DNA sequence data becoming available, MS-based proteomics also have increasingly been applied to biological studies. Proteomic analyses of bacterial cells may be considered indirect analyses of the genomes of bacteria. The ‘proteome’ comprises the entire set of proteins expressed by a cell, an organism or a biological system. ‘Proteotyping’ [2], using state-ofthe-art LC-MS/MS analyses of generated cellular peptides, enables identification of the most closely related bacterial species and sub-species-level strain discrimination, AMR- and virulence-factors, from single MS analyses. Comprehensive and accurate genome sequence data is the key to obtaining accurate peptide matching and to be able to discriminate between the most closely related species. In this study, genome sequences were analysed, using Average Nucleotide Identity Blast (ANIb) and taxon-specific MLSA to assess their reliabilities. Critically, significant numbers of sequenced genomes in the public databases exhibited questionable identifications. Characterisations and identifications of responsible agents of infectious disease have relied heavily upon established systematic frameworks and the documented features of well-described microbial species. As methodologies, such as whole-genome sequencing and MS proteomics are developed to enable more comprehensive, detailed and complex analyses, comprehensive databases derived from a reliable systematic framework are essential. References [1] World Health Organization (WHO). (2014) Antimicrobial Resistance: Global Report on Surveillance. ISBN: 978-92-4-15674-8. [2] Karlsson et al. [2015) Proteotyping: Proteomic characterization, classification and identification of microorganisms – A prospectus. Syst. Appl. Microbiol. 38: 246-257.
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| 18. |
- Myhrman, Sofia, et al.
(författare)
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Unexpected details regarding nosocomial transmission revealed by whole-genome sequencing of SARS-CoV-2
- 2022
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Ingår i: Infection Control and Hospital Epidemiology. - : Cambridge University Press (CUP). - 0899-823X .- 1559-6834. ; 43:10, s. 1403-1407
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Effective infection prevention and control (IPC) measures are key for protecting patients from nosocomial infections and require knowledge of transmission mechanisms in different settings. We performed a detailed outbreak analysis of the transmission and outcome of coronavirus disease 2019 (COVID-19) in a geriatric ward by combining whole-genome sequencing (WGS) with epidemiological data. Design: Retrospective cohort study. Setting: Tertiary care hospital. Participants: Patients and healthcare workers (HCWs) from the ward with a nasopharyngeal sample (NPS) positive for SARS-CoV-2 RNA during the outbreak period. Methods: Patient data regarding clinical characteristics, exposure and outcome were collected retrospectively from medical records. Stored NPS from 32 patients and 15 HCWs were selected for WGS and phylogenetic analysis. Results: Median patient age was 84 years and 17/32 (53%) were male. Fourteen patients (44%) died within 30 days after sampling. Viral load was significantly higher among the deceased. WGS was successful in 28/32 (88%) patient samples and 14/15 (93%) HCW samples. Three separate viral clades were identified, whereof one clade and two subclades among both patient and HCW samples. Integrated epidemiological and genetic analysis revealed six probable transmission events between patients and supported hospital-acquired COVID-19 in 25/32 patients. Conclusion: WGS provided a deep insight into the outbreak dynamics and true extent of nosocomial COVID-19. The extensive transmission between patients and HCWs indicated that current IPC measures were insufficient. We suggest increased use of WGS in outbreak investigations for identification of otherwise unknown transmission links and evaluation of IPC measures.
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| 19. |
- Olausson, Josefin, 1983, et al.
(författare)
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Optimization of cerebrospinal fluid microbial DNA metagenomic sequencing diagnostics
- 2022
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Infection in the central nervous system is a severe condition associated with high morbidity and mortality. Despite ample testing, the majority of encephalitis and meningitis cases remain undiagnosed. Metagenomic sequencing of cerebrospinal fluid has emerged as an unbiased approach to identify rare microbes and novel pathogens. However, several major hurdles remain, including establishment of individual limits of detection, removal of false positives and implementation of universal controls. Twenty-one cerebrospinal fluid samples, in which a known pathogen had been positively identified by available clinical techniques, were subjected to metagenomic DNA sequencing. Fourteen samples contained minute levels of Epstein-Barr virus. The detection threshold for each sample was calculated by using the total leukocyte content in the sample and environmental contaminants found in the bioinformatic classifiers. Virus sequences were detected in all ten samples, in which more than one read was expected according to the calculations. Conversely, no viral reads were detected in seven out of eight samples, in which less than one read was expected according to the calculations. False positive pathogens of computational or environmental origin were readily identified, by using a commonly available cell control. For bacteria, additional filters including a comparison between classifiers removed the remaining false positives and alleviated pathogen identification. Here we show a generalizable method for identification of pathogen species using DNA metagenomic sequencing. The choice of bioinformatic method mainly affected the efficiency of pathogen identification, but not the sensitivity of detection. Identification of pathogens requires multiple filtering steps including read distribution, sequence diversity and complementary verification of pathogen reads.
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| 20. |
- Ringlander, Johan, et al.
(författare)
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Recurrent and persistent infection with SARS-CoV-2-epidemiological data and case reports from Western Sweden, 2020
- 2021
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Ingår i: Infectious Diseases. - : Informa UK Limited. - 2374-4235 .- 2374-4243. ; 53:12, s. 900-907
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Tidskriftsartikel (refereegranskat)abstract
- Background Reinfections with SARS-CoV-2 have been reported and most cases were classified as mild. Reports of persistent infection with SARS-CoV-2 are rare. Aim To investigate the frequency of recurrent and persistent infection with SARS-CoV-2. Methods Possible cases of reinfection and persistent infection were retrospectively identified in a database of 59,998 patients. Deep sequencing of SARS-CoV-2 genomes was performed. Results We report the first case of COVID-19 reinfection in Sweden and three cases of infection with persistence over several months. The rate of sequencing-verified reinfection was 0.02% (one patient out of 6014 patients testing positive during the period). Conclusions The reinfected patient had mild symptoms during the second episode, which might reflect partial immunity. The frequency of reinfection during the first wave of the pandemic in western Sweden was very low. Our results indicate that elderly with a putative reinfection more likely have persistent COVID-19.
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| 21. |
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| 22. |
- Salvà-Serra, Francisco, 1989, et al.
(författare)
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Draft Genome Sequence of Streptococcus gordonii Type Strain CCUG 33482T.
- 2016
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Ingår i: Genome Announcements. - 2169-8287. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- Streptococcus gordoniitype strain CCUG 33482(T)is a member of theStreptococcus mitisgroup, isolated from a case of subacute bacterial endocarditis. Here, we report the draft genome sequence ofS. gordoniiCCUG 33482(T), composed of 41 contigs of a total size of 2.15 Mb with 2,061 annotated coding sequences.
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| 23. |
- Salvà-Serra, Francisco, 1989, et al.
(författare)
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Proteotyping for Rapid Identifications of Clinically-Relevant Infectious Bacteria
- 2016
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Ingår i: Programme of the XXXV ECCO Meeting 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Aims The development and application of novel identifications and diagnostics of pathogenic bacteria, virulence and antibiotic resistance factors, to enhance treatment of infectious diseases and to address the pandemic of antimicrobial resistance (1). To apply mass spectrometry (MS)-based ‘proteotyping’, a rapid proteomic-genomic method to identify and use cell biomarkers for pathogen identification and detection of targeted metabolic functions (www.tailored-treatment.eu/). Methods and results The proteins of intact bacterial cells or cell-fractions are bound to a membrane surface, using the patented (WO2006068619) Lipid-based Protein Immobilization (LPI) technology. Peptides are generated from bound proteins, using enzymatic digestion, separated and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The MS profiles are compared to those of reference peptide sequences and the peptide sequences are compared against a curated in-house database of genome sequences. Conclusions Analyses of bacterial cell peptides identified protein biomarkers of infectious bacteria, at the species-level, virulence and antibiotic resistance factors. Model samples have been ‘proteotyped’, using well-characterized reference strains, and an enhanced whole-genome sequence database, to demonstrate ‘proof-of-concept’, and the method been applied directly to the analyses of clinical samples, without prior cultivation. Significance of study Proteotyping demonstrates the potential for proteomics-based analyses for detecting expressed genomic markers of bacterial species, virulence and antibiotic resistance, for the identifications and diagnostics of infectious microorganisms. References Cohen A, Bont L, Engelhard D, Moore E, Fernández D, Kreisberg-Greenblatt R, Oved K, Eden E, Hayes J (2015). A multifaceted 'omics' approach for addressing the challenge of antimicrobial resistance. Future Microbiol. 10:365-376
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- Tång Hallbäck, Erika, 1973, et al.
(författare)
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Methicillin-resistant Staphylococcus argenteus misidentified as methicillin-resistant Staphylococcus aureus emerging in western Sweden
- 2018
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Ingår i: Journal of Medical Microbiology. - : Microbiology Society. - 0022-2615 .- 1473-5644. ; 67:7, s. 968-971
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Tidskriftsartikel (refereegranskat)abstract
- Two strains included in a whole-genome sequencing project for methicillin-resistant Staphylococcus aureus (MRSA) were identified as non-Staphylococcus aureus when the sequences were analysed using the bioinformatics software ALEX (www.1928diagnostics.com, Gothenburg, Sweden). Sequencing of the sodA gene of these strains identified them as Staphylococcus argenteus. The collection of MRSA in western Sweden was checked for additional strains of this species. A total of 18 strains of S. argenteus isolated between 2011 and December 2017 were identified.
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