GREfm
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ABSTRACT:
PROVIDER: PRJEB87619 | ENA |
REPOSITORIES: ENA
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Project description:Enterococcus faecium has emerged as a major opportunistic pathogen for two decades, with the spread of hospital-adapted multidrug-resistant clones. Members of the intestinal microbiota, they are subjected to numerous bacterial stresses, including antibiotics at subinhibitory concentrations (SICs). Since fluoroquinolones are extensively prescribed, SICs are very likely to occur in vivo with potential effects on bacterial metabolism with subsequent modulation of opportunistic traits. The aim of the study was to evaluate globally the impact of subinhibitory concentrations (SICs) of ciprofloxacin on antimicrobial resistance and pathogenicity of E. faecium. Transcriptomic analysis was performed by RNA-seq (HiSeq 2500, Illumina) using the vanB-positive reference strain E. faecium Aus0004 in the absence or presence of ciprofloxacin SIC (0.38 mg/L, i.e. MIC 1/8). Several genetic and phenotypic tests were used for validation. In the presence of ciprofloxacin SIC, 196 genes were significantly induced whereas 286 were significantly repressed, meaning that 16.8% of the E. faecium genome was altered. Amongst upregulated genes, EFAU004_02294 (fold change of 14.3) encoded a protein (EfmQnr) homologue of Qnr proteins involved in quinolone resistance in Gram-negative bacilli. Its implication in intrinsic and adaptive FQ resistance in E. faecium was experimentally ascertained. Moreover, EFAU004_02292 coding for the collagen adhesin Acm was also induced by SIC of ciprofloxacin (fold change of 8.2), and higher adhesion capabilities were demonstrated phenotypically. Both Efmqnr and Acm determinants may play an important role in the transition from a commensal to a pathogenic state of E. faecium that resides in the gut of patients receiving a fluoroquinolone therapy.
2017-02-04 | GSE94507 | GEO
Project description:The enterococci comprise a genus of 49 low-GC content Gram-positive commensal species within the Firmicutes phylum that are known to occupy diverse habitats, notably the gastrointestinal core microbiota of nearly every phylum, including human. Of particular clinical relevance are two rogue species of enterococci, Enterococcus faecalis and the distantly related Enterococcus faecium, standing among the nefarious multi-drug resistant and hospital-acquired pathogens. Despite increasing evidence for RNA-based regulation in the enterococci, including regulation of virulence factors, their transcriptome structure and arsenal of regulatory small sRNAs (sRNAs) are not thoroughly understood. Using dRNA-seq, we have mapped at single-nucleotide resolution the primary transcriptomes of E. faecalis V583 and E. faecium AUS0004. We identified 2517 and 2771 transcription start sites (TSS) in E. faecalis and E. faecium, respectively. Based on the identified TSS, we created a global map of s70 promoter motifs. We also revealed features of 5’ and 3’UTRs across the genomes. The transcriptome maps also predicted 150 and 128 sRNA candidates in E. faecalis and E. faecium, respectively, some of which have been identified in previous studies and many of which are new. Finally, we validated several of the predicted sRNAs by Northern Blot in biologically relevant conditions. Comprehensive TSS mapping of two representative strains will provide a valuable resource for the continued development of RNA biology in the Enterococci.
2020-11-25 | GSE115009 | GEO
Project description:Regulatory RNAs (sRNAs) are now considered as major players in many physiological and adaptive responses in pathogenic bacteria. sRNAs have been extensively studied in Gram-negative bacteria, but less information is available in Gram-positive pathogens. There is a spread of multidrug-resistant (MDR) opportunistic organisms, grouped as “ESKAPE” pathogens, which comprise enterococci, a leading cause of hospital-acquired infections and outbreaks with emergence of MDR isolates, especially vancomycin-resistant Enterococcus faecium (VREF). Note that no information about sRNA expression is known in this major opportunistic pathogen. By transcriptomic and genomic analyses using E. faecium Aus0004 reference strain, 249 transcribed IGRs, including sRNA candidates, were detected and, using a series of cut-offs, this set was lowered down to 54 sRNAs while 7 that were predicted based on comparative sequence analysis. RNA-seq was performed with and without subinhibitory concentrations (SIC) of daptomycin, a cyclic lipopeptide antibiotic used for VREF infections. Under daptomycin SIC exposure, 260 genes (9.1% of the genome) had a significant alteration of expression including 80 upregulated genes and 180 downregulated genes. Among the repressed genes, a large proportion (55%) coded for proteins involved in carbohydrate and transport metabolism. Also, we focused on the 9 sRNAs exhibiting the highest expression, and all of them were confirmed as expressed along bacterial growth by Northern blots and qPCR. Out of these 9 sRNAs, four had significantly lower or higher expression in the presence of daptomycin SIC, and therefore responded to antibiotic exposure. Finally, we also tested the expression of these 9 sRNAs in a collection of isogenic Aus0004 mutants with increasing levels of daptomycin resistance, and we observed by qPCR that some sRNAs had a significantly modified expression in daptomycin resistance mutants. It highlights the significant implication of some of the E. faecium sRNAs in the early steps of the development of daptomycin resistance. This is the first experimental genome-wide sRNA identification in Gram-positive E. faecium, a leading cause of hospital acquired infections.
2017-02-16 | GSE94924 | GEO
Project description:Comparative genomics of DQ-resistant and DQ-susceptible glycopeptide resistant Enterococcus faecium
| PRJEB24855 | ENA
Project description:Enterococcus faecium is a member of the human gut microbiota that has evolved to be a problematic nosocomial pathogen and a leading cause of bloodstream infections in hospitalized patients. Treatment of E. faecium infections is complicated by antibiotic resistance, making it important to understand resistance mechanisms and their broader consequences in this pathogen. Here we explored the collateral effects of rifampin resistance-associated mutations in the E. faecium RNA polymerase β-subunit (RpoB). Of 14,384 publicly available E. faecium genomes, nearly one-third carried a mutation in the rifampin resistance-determining region (RRDR) of RpoB. In a local population of 710 E. faecium isolates collected from patients at a single medical center, we found significant associations between the presence of RRDR mutations and prior exposure to rifamycin class antibiotics, as well as associations between RRDR mutations and altered daptomycin susceptibility. To investigate the phenotypic impacts of RRDR mutations, we studied four isogenic strains with distinct RRDR mutations (Q473K, G482D, H486Y, S491L) that overlapped with clinical isolate variants. Transcriptomic and phenotypic analyses revealed allele-specific effects on E. faecium gene expression, growth dynamics, antibiotic susceptibility, isopropanol tolerance, and cell wall physiology. One frequently observed mutation, H486Y, caused minimal transcriptional changes and enhanced bacterial fitness. In contrast, the S491L mutation induced extensive transcriptional changes and slowed bacterial growth, but also conferred increased isopropanol tolerance, potentially enhancing bacterial survival in the hospital environment. Overall, our findings highlight the multifaceted impacts of RRDR mutations in shaping E. faecium physiology and antibiotic resistance, two important features of this hospital-associated pathogen.
2025-08-10 | GSE302807 | GEO
Project description:The success of Enterococcus faecium and E. faecalis evolving as multi-resistant nosocomial pathogens is associated with their ability to acquire and share adaptive traits, including mobile genetic elements (MGE) encoding antimicrobial resistance. Here, we define the mobilome in representative successful hospital associated genetic lineages, E. faecium ST17 (n=10) and ST78 (n=10), E. faecalis ST6 (n=10) and ST40 (n=10) using DNA microarray analyses. The hybridization patterns of 272 targets representing plasmid backbones (n=85), transposable elements (n=85), resistance determinants (n=67), prophages (n=29), and CRISPR-cas sequences (n=6) separated the strains according to species, and for E. faecalis also according to STs. Although plasmids belonging to the RCR-, Rep_3-, RepA_N- and Inc18-families were well represented with no significant differences in prevalence, the presence of specific replicon classes differed highly between the species; E. faecium was dominated by rep17/pRUM, rep2/pRE25, rep14/EFNP1 and rep20/pLG1 and E. faecalis by rep9/pCF10, rep2/pRE25 and rep7. Tn916-elements conferring tetracycline resistance (tetM) were found in all E. faecalis strains, but only in two E. faecium strains. A significant higher prevalence of IS256-, IS3-, ISL3-, IS200/IS605-, IS110-, IS982-, and IS4-transposases were detected in E. faecium, and of IS110-, IS982- and IS1182-transposases in E. faecalis ST6 compared to ST40. Notably, the transposases of IS981, ISEfm1 and IS1678 which have only been reported in few enterococcal isolates, were well represented in the E. faecium strains. E. faecalis ST40 strains harboured possible functional CRISPR-Cas systems, and still resistance and prophage sequences were generally well represented. Gene targets defined as the enterococcal mobilome, including plasmids, IS elements and transposons, resistance determinants, prophage sequences and CRISPR-Cas systems were highly prevalent, underlining their potential importance in the evolution of hospital associated STs. An association between axe-txe to the RepA_N-family and ω-ε-ζ to the Inc18-family, implicates the contribution of TA-systems in stable plasmid maintenance carrying virulence and resistance determinants in enterococci. The concurrent presence of defined MGE and their associated resistance markers was generally confirmed and illustrates the importance of horizontal gene transfer in the development of multidrug resistant enterococci.
2014-07-08 | GSE59190 | GEO
Project description:This study aims to determine the epidemiology of Enterobacteriaceae resistant to antibiotics of last resort in pregnant women in labour at a tertiary hospital, Pretoria, South Africa. Rectal swabs shall be used to screen for colonisation with CRE and colistin-resistant Enterobacteriales in pregnant women during labour. Carbapenem and colistin-resistant Enterobacterales can cause the following infections: bacteraemia; nosocomial pneumonia; urinary tract infections, and intra-abdominal infections. Due to limited treatment options, infections caused by these multidrug-resistant organisms are associated with a mortality rate of 40-50%. Screening for colonisation of carbapenem-resistant Enterobacteriaceae (CRE) and colistin-resistant Enterobacteriaceae will help implement infection and prevention measures to limit the spread of these multidrug-resistant organisms.
2022-07-20 | GSE208573 | GEO
Project description:Grad-seq in Enterococcus faecalis V583 and Enterococcus faecium AUS004.
2022-11-28 | PXD031577 | Pride
Project description:Young adult N2 Caenorhabditis elegans were infected with Enterococcus faecalis or Enterococcus faecium for 8 h to determine the transcriptional host response to each enterococcal species. Analysis of differential gene expression in C. elegans young adults exposed to four different bacteria: heat-killed Escherichia coli strain OP50 (control), wild-type E. faecalis MMH594, wild-type E. faecium E007, or Bacillus subtilis PY79 (sigF::kan). Samples were analyzed at 8 hours after exposure to the different bacteria. These studies identified C. elegans genes induced by pathogen infection. Brain-heart infusion agar plates (10 ug/ml kanamycin) were used.
2018-02-14 | GSE95636 | GEO