| 1. |
- Birindwa, Archippe M., et al.
(författare)
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High bacterial and viral load in the upper respiratory tract of children in the Democratic Republic of the Congo
- 2020
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- © 2020 Muhandule Birindwa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background Respiratory pathogens including Streptococcus pneumoniae and Haemophilus influenzae, are implicated in the pathogenicity of acute lower respiratory infection (ALRI). These are also commonly found in both healthy and sick children. In this study, we describe the first data on the most frequent bacteria and viruses detected in the nasopharynx of children from the general population in the Eastern DR Congo. Methods From January 2014 to June 2015, nasopharyngeal samples from 375 children aged from 2 to 60 months attending health centres for immunisation or growth monitoring were included in the study. Multiplex real-time PCR assays were used for detection of 15 different viruses and 5 bacterial species and for determination of pneumococcal serotypes/serogroups in the nasopharyngeal secretions. Results High levels of S. pneumoniae were detected in 77% of cases, and H. influenzae in 51%. Rhinovirus and enterovirus were the most commonly found viruses, while respiratory syncytial virus (RSV) was rare (1%). Co-occurrence of both bacteria and viruses at high levels was detected in 33% of the children. The pneumococcal load was higher in those children who lived in a dwelling with an indoor kitchen area with an open fire, i.e. a kitchen with an open fire for cooking located inside the dwelling with the resultant smoke passing to the living room and/or bedrooms; this was also higher in children from rural areas as compared to children from urban areas or children not living in a dwelling with an indoor kitchen area with an open fire/not living in this type of dwelling. Immunization with 2–3 doses of PCV13 was associated with lower rates of pneumococcal detection. Half of the identified serotypes were non-PCV13 serotypes. The most common non-PCV13 serotypes/serogroups were 15BC, 10A, and 12F, while 5, 6, and 19F were the most prevalent PCV13 serotypes/serogroups. Conclusions The burden of respiratory pathogens including S. pneumoniae in Congolese children was high but relatively few children had RSV. Non-PCV13 serotypes/serogroups became predominant soon after PCV13 was introduced in DR Congo.
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| 2. |
- Carvalheira, A., et al.
(författare)
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Acinetobacter portensis sp. Nov. and acinetobacter guerrae sp. nov., isolated from raw meat
- 2020
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Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 70:8, s. 4544-4554
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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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| 3. |
- Gonzales-Siles, Lucia, et al.
(författare)
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A Pangenome Approach for Discerning Species-Unique Gene Markers for Identifications of Streptococcus pneumoniae and Streptococcus pseudopneumoniae
- 2020
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Ingår i: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media SA. - 2235-2988. ; 10
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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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| 4. |
- Jaén-Luchoro, Daniel, et al.
(författare)
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Corynebacterium sanguinis sp. nov., a clinical and environmental associated corynebacterium.
- 2020
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Ingår i: Systematic and applied microbiology. - : Elsevier BV. - 1618-0984 .- 0723-2020. ; 43:1
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Tidskriftsartikel (refereegranskat)abstract
- Clinical and environmental-associated strains (n=17), genotypically related to Corynebacterium spp., yet distinct from any species of the genus Corynebacterium with validly published names, have been isolated during the last 20 years and tentatively identified as Corynebacterium sanguinis, although the combination, "Corynebacterium sanguinis" was never validly published. The comprehensive genotypic and phenotypic characterisations and genomic analyses in this study support the proposal for recognizing the species within the genus Corynebacterium, for which the name, Corynebacterium sanguinis sp. nov., is reaffirmed and proposed. Strains of Corynebacterium sanguinis are Gram-positive, non-motile, non-spore-forming, short, pleomorphic and coryneform bacilli, growing aerobically, with CO2. They contain mycolic acids, major respiratory menaquinones, MK-8 (II-H2) and MK-9 (II-H2), and polar lipids, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphoglycolipid, glycolipids and a novel lipid that remains to be characterized and identified. Strains of Corynebacterium sanguinis are genotypically most similar to Corynebacterium lipophiliflavum, with 16S rRNA gene sequence similarities of 98.3% and rpoB sequence similarities of 94.9-95.2%. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis were able to clearly differentiate Corynebacterium sanguinis from the most closely related species. The genome size of Corynebacterium sanguinis is 2.28-2.37Mbp with 65.1-65.5mol% G+C content. A total of 2202-2318 ORFs were predicted, comprising 2141-2251 protein-encoding genes. The type strain is CCUG 58655T (=CCM 8873T=NCTC 14287T).
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| 5. |
- 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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| 6. |
- 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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