The Transcriptome of the Nosocomial Pathogen Enterococcus faecalis V583 Reveals Adaptive Responses to Growth in Blood

gains access to the bloodstream and establishes a persistent infection is not well understood.. infections

Comparative Genomic Analysis of Pathogenic and Probiotic Enterococcus faecalis Isolates, and Their Transcriptional Responses to Growth in Human Urine

Urinary tract infection (UTI) is the most common infection caused by enterococci, and Enterococcus faecalis accounts for the majority of enterococcal infections. Although a number of virulence related traits have been established, no comprehensive genomic or transcriptomic studies have been conducted to investigate how to distinguish pathogenic from non-pathogenic E. faecalis in their ability to cause UTI. In order to identify potential genetic traits or gene regulatory features that distinguish pathogenic from non-pathogenic E. faecalis with respect to UTI, we have performed comparative genomic analysis, and investigated growth capacity and transcriptome profiling in human urine in vitro. Six strains of different origins were cultivated and all grew readily in human urine. The three strains chosen for transcriptional analysis showed an overall similar response with respect to energy and nitrogen metabolism, stress mechanism, cell envelope modifications, and trace metal acquisition. Our results suggest that citrate and aspartate are significant for growth of E. faecalis in human urine, and manganese appear to be a limiting factor. The majority of virulence factors were either not differentially regulated or down-regulated. Notably, a significant up-regulation of genes involved in biofilm formation was observed. Strains from different origins have similar capacity to grow in human urine. The overall similar transcriptional responses between the two pathogenic and the probiotic strain suggest that the pathogenic potential of a certain E. faecalis strain may to a great extent be determined by presence of fitness and virulence factors, rather than the level of expression of such traits

Characterization of the ebpfm pilus-encoding operon of Enterococcus faecium and its role in biofilm formation and virulence in a murine model of urinary tract infection

We recently identified 15 genes encoding putative surface proteins with features of MSCRAMMs and/or pili in the Enterococcus faecium TX16 (DO) genome, including four predicted pilus-encoding gene clusters; we also demonstrated that one of these, ebpABCfm, is transcribed as an operon, that its putative major pilus subunit, EbpCfm (also called PilB), is polymerized into high molecular weight complexes, and that it is enriched among clinical E. faecium isolates. Here, we created a deletion of the ebpABCfm operon in an endocarditis-derived E. faecium strain (TX82) and showed, by a combination of whole-cell ELISA, flow cytometry, immunoblot and immunogold electron microscopy, that this deletion abolished EbpCfm expression and eliminated EbpCfm-containing pili from the cell surface. However, transcription of the downstream sortase, bpsfm, was not affected. Importantly, the ebpABCfm deletion resulted in significantly reduced biofilm formation (p < 0.0001) and initial adherence (p < 0.0001) versus the wild-type; both were restored by complementing ebpABCfm in trans, which also restored cell surface expression of EbpCfm and pilus production. Furthermore, the deletion mutant was significantly attenuated in two independent mixed infection mouse urinary tract experiments, i.e., outnumbered by the wild-type in kidneys (p = 0.0003 and <0.0001, respectively) and urinary bladders (p = 0.0003 and = 0.002). In conclusion, we have shown that the ebpABCfm locus encodes pili on the E. faecium TX82 cell surface and provide the first evidence that pili of this emerging pathogen are important for its ability to form biofilm and to cause infection in an ascending UTI model

Recommendations for the use of electrophysiological study: Update 2018

International audienceThe field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published.The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic.For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed.Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases.In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures