Project description:Comparative genomic analysis of the most important S. enterica sspI clinical isolates and respective strains from the SARB collection Keywords: other
2004-05-10 | GSE1035 | GEO
Project description:Collection of Clinical Klebsiella Isolates
Project description:Comparative genomic analysis of the most important S. enterica sspI clinical isolates and respective strains from the SARB collection
Project description:Purpose: The goal of this study was to elucidate the collateral effects associated with OXA-23 overexpression on the Acinetobacter baumannii global transcriptome. Results: Besides the 99.73-fold increase in blaOXA-23 transcript upon IPTG induction, no other transcripts showed more than a 2-fold change compared to the wildtype control. This suggests that OXA-23 over expression to levels similarly observed in multi drug resistant A. baumannii clinical isolates does not effect the transcriptome.
Project description:Background. The Beijing family of Mycobacterium tuberculosis is dominant in countries in East Asia. Genomic polymorphisms are a source of diversity within the M.tuberculosis genome and may account for the variation of virulence among M.tuberculosis isolates. To date there are no studies that have examined the genomic composition of M.tuberculosis isolates from the high TB-burden country, Myanmar. Methodology/Principle findings. Twenty-two M.tuberculosis isolates from Myanmar were screened on whole-genome arrays containing genes from M.tuberculosis H37Rv, M.tuberculosis CDC1551 and M.bovis AF22197. Screening identified 198 deletions or extra regions in the clinical isolates compared to H37Rv. Twenty-two regions differentiated between Beijing and non-Beijing isolates and were verified by PCR on an additional 40 isolates. Six regions (Rv0071-0074 [RD105], Rv1572-1576c [RD149], Rv1585c-1587c[RD149], MT1798-Rv1755c [RD152], Rv1761c [RD152] and Rv0279c) were deleted in Beijing isolates, of which 4 (Rv1572-1576c, Rv1585c-1587c, MT1798-Rv1755c and Rv1761c) were variably deleted among ST42 isolates, indicating a closer relationship between the Beijing and ST42 lineages. The TbD1 region, Mb1582-Mb1583 was deleted in Beijing and ST42 isolates. One M.bovis gene of unknown function, Mb3184c was present in all isolates, except 11 of 13 ST42 isolates. The CDC1551 gene, MT1360 coding for a putative adenylate cyclase, was present in all Beijing and ST42 isolates (except 1). The pks15/1 gene, coding for a putative virulence factor, was intact in all Beijing and non-Beijing isolates, except in ST42 and ST53 isolates. Conclusion. This study describes previously unreported deletions/extra regions in Beijing and non-Beijing M.tuberculosis isolates. The modern and highly frequent ST42 lineage showed a closer relationship to the hypervirulent Beijing lineage than to the ancient non-Beijing lineages. The pks15/1 gene was disrupted only in modern non-Beijing isolates. This is the first report of an in-depth analysis on the genomic diversity of M.tuberculosis isolates from Myanmar. Data is also available from http://bugs.sgul.ac.uk/E-BUGS-66
Project description:Nosocomial outbreaks of infections caused by multidrug-resistant Acinetobacter baumannii have emerged as a serious threat to human health. The phosphoproteomics of pathogenic bacteria have been investigated for their role in virulence regulation networks. In this study, we analyzed the phosphoproteomics of two clinical isolates of A. baumannii: imipenem-sensitive strain SK17-S and -resistant strain SK17-R.
Project description:The release of cells from S. epidermidis biofilms formed on medical devices has been associated with the onset of bloodstream infections, resulting in increased morbidity and mortality rates. This has to do, in part, with the difficulty to accurately diagnose S. epidermidis bloodstream infections. S. epidermidis is a ubiquitous commensal of human skin and mucosa and, thus, a positive blood culture does not always represent an infection, possibly being the result of contamination during blood collection. As such, there is a high demand to find markers that can help clinicians to distinguish infection (clinical isolates) from contamination (commensal strains). With that in mind, several studies comparing phenotypic or genetic characteristics of clinical and commensal isolates have been performed over the years. However, because S. epidermidis virulence factors seem to be the same that confer its fitness as a commensal, we hypothesized that the ability of S. epidermidis strains to adapt to the host environment may not depend on a specific phenotypic and/or genetic makeup, but rather on the regulation of gene transcription. Thus, using RNA-Sequencing (RNA-seq), we characterized the transcriptome of commensal and clinical isolates in the context of infection to try to uncover differences and, thus, identify markers that could be used for the diagnostics. Several markers with the potential to discriminate between both groups were highlighted. Nevertheless, when the results obtained were confirmed in a wider collection of clinical and commensal isolates the discriminatory power of the genes initially identified was lost. Although we cannot rule out that the characterization of a larger collection of isolates would identify potential candidates, our transcriptomic data was not able to confirm our initial hypothesis, evidencing S. epidermidis opportunistic nature.