Emergence of cephalosporin resitance in cephalosporin-sensitive class A penicillin binding protein mutants in Enterococcus faecium
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ABSTRACT:
ORGANISM(S): Enterococcus faecium
PROVIDER: GSE77436 | GEO | 2016/02/19
SECONDARY ACCESSION(S): PRJNA310329
REPOSITORIES: GEO
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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:A set of small RNAs was identified in Vancomycin-resistant Enterococcus faecium, a leading cause of MDR infections. We described here the function of srn_2050, acting as a T-box riboswitch to regulate expression of downstream genes encoding the HisRS and AspRS aminoacyl-tRNA synthetases. Comparative RNAseq between Aus0004 and isogenic srn_2050 mutant identified the genes whose expression is impacted by the RNA. srn_2050 structure in its ‘off state’ was deciphered by in-line probing, containing T-box consensus sequences, a pseudoknot, a specifier loop and a terminator. Transcription binding assays between the riboswitch and either tRNAAsp or tRNAHis indicate that each deacylated tRNA interacts with the T-box. Their anticodons bind to a GACAC sequence within the specifier loop (GAC and CAC are Asp and His codons, respectively), whereas tRNATyr (UA/C-U) does not. A pioneering evaluation of E. faecium amino acid auxotrophy, with emphasis on E. faecium strain Aus0004, revealed auxotrophy for Histidine but not for Aspartic acid. Based on comparative growths and RNAseq between Aus004 and Aus004-srn2050, the riboswitch is shown essential for growth under aspartate starvation. This is the first example of a functional riboswitch in E. faecium with two overlapping codons allowing a dual tRNA-dependent regulation at transcriptional level.
2020-11-16 | GSE161499 | GEO
Project description:Two independent aliquots containing approximately 10^7 cells from the transposon mutant of E. faecium E1162 were grown at 37 C for 20 hours in 20 ml of BHI broth. Genomic DNA was isolated from the two replicate cultures and used for the generation of cDNA. The cDNA samples were labeled with Cy3 and Cy5 respectively and hybridized to a microarray that was designed using the E. faecium E1162 genome sequence.
2012-11-02 | E-MEXP-3502 | biostudies-arrayexpress
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:In our study, we employed activity-based protein profiling (ABPP), a technique that uses specialized inhibitors to identify active serine hydrolases in different strains of E. faecium (clade A1 and A2) and E. lactis under various growth conditions. Serine hydrolases, a large and diverse family of enzymes that include established drug targets like penicillin-binding proteins, have other less-studied subfamilies. In addition to fluorescent, gel-based profiling, we used a biotin-tagged fluorophosphonate probe for the enrichment and identification of serine hydrolase enzymes via streptavidin enrichment and liquid chromatography/mass spectrometry analysis. This led to the discovery of 11 largely unexplored potential targets (including α,β-hydrolases, SGNH-hydrolases, phospholipases, amidases, and peptidases) that could be exploited for drug developmentagainst the vancomycin-resistant E. faecium strain E745.
2024-06-22 | PXD048798 | Pride
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:Enterococcus faecium has become a major opportunistic pathogen with the emergence of multidrug-resistant clones that are well-adapted to the hospital environment. As part of the vast diversity of gut microbiota, they are faced with different environmental stress, including antimicrobial pressure. By contrast, little is known about the effect of non-antibiotic molecules on bacterial physiology while numerous drugs are used in inpatients, especially those hospitalized in intensive care units (ICUs). The aim of this study was to investigate the impact of the most prescribed xenobiotics in ICUs on fitness, pathogenicity and antimicrobial resistance of E. faecium. Several phenotypic analysis was carried out and we rapidly brought to light that caspofungin, an antifungal agent belonging to the echinocandin family, seemed to have an important impact on E. faecium growth. Since the fungal target of caspofungin [beta-(1,3)-glucan synthase] is absent in enterococci, the mechanism of caspofungin action was investigated by several approaches. First, we decided to confirm this result by electronic microscopy and a peptidoglycan analysis by Ultra Performance Liquid Chromatography coupled with mass spectrometry (UPLC-MS/MS). Again, we highlighted that caspofungin even at subinhibitory concentrations (SICs) seemed to have an impact on cell wall organization especially in muropeptide precursors abundance. Then, a transcriptomic analysis was performed by RNA-seq (HiSeq 2500, Illumina) using the vanB-positive reference strain E. faecium Aus0004 in the presence or absence of caspofungin SIC (8 mg/L i.e., ¼ of the MIC). Transcriptomic analysis showed that the expression of 568 genes (19.9% of the genome) was significantly altered in the presence of caspofungin SIC, with 323 genes induced (fold change >2, p-value <0.1) and 245 genes repressed (fold change <-2, p-value <0.1). Regarding the repressed genes, the pdhABCD operon is largely downregulated (fold changes -4.3, -9.7, -6.9 and -6.4, respectively). This operon encoded components of the pyruvate deshydrogenase multienzyme complex involved in bacterial energetic pathway by the citrate cycle (i.e., TCA cycle). Moreover, it seemed that the glycerol metabolism pathway and in particular the glpOKF operon is downregulated too. The dramatic alteration of TCA seemed to have an drastic impact on bacterial cells viability indeed decrease of glycerol metabolism could explain the conformational modifications of peptidoglycan.
2017-06-16 | GSE100091 | GEO
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2024-08-15 | PXD039831 | Pride
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Project description:Grad-seq in Enterococcus faecalis V583 and Enterococcus faecium AUS004.
2022-11-28 | PXD031577 | Pride