Characterization of biofilm formation by Enterococcus faecalis isolates derived from urinary tract infections in China.

Purpose. This study explored the prevalence and characteristics of Enterococcus faecalis biofilm formation by urinary tract infection (UTI) isolates in order to identify virulence factors associated with biofilm formation.Methodology. A total of 113 E. faecalis isolates were collected from UTI patients in Shenzhen, China. The isolates were subjected to multilocus sequence typing based on housekeeping genes. Biofilms were detected by crystal violet staining and the expression levels of the E. faecalis genes were detected by quantitative real-time PCR.Results/Key findings. The main sequence types (STs) were ST16 and ST179 with the ST16 isolates more likely to form strong biofilms than the ST179 isolates (P=0.008). Strong biofilm formation was more frequently detected in aggregation substance (agg)-positive (+) isolates than in negative (-) isolates (P=0.033). Biofilm formation was also more common in isolates containing enterococcal surface protein (esp), or cytolysin A (cylA)-positive (+) isolates than in isolates negative (-) for these virulence factors. Multivariate regression analysis indicated that cylA [odds ratio (OR), 7.143, P=0.012] was associated with weak biofilm formation, and that agg (OR, 4.471, P=0.004) was associated with strong biofilm formation. The expression of cylA was increased (8.75- to 23.05-fold) in weak biofilm, and the expression of agg was greatly elevated (11.99- to 439.10-fold) in strong biofilm isolates when compared to biofilm-negative isolates.Conclusion. ST16 classification was positively associated with strong biofilm formation in E. faecalis as was agg, while cylA was associated with weak biofilm formation.

Bloodstream infections caused by Enterococcus spp: A 10-year retrospective analysis at a tertiary hospital in China.

In order to discover the risk factors for 30-day mortality in bloodstream infections (BSI) caused by Enterococcus spp. strains, we explored the clinical and therapeutic profile of patients with Enterococcus spp. BSI and the characteristics of this condition. A total of 64 patients with BSI caused by Enterococcus spp. who were treated in our hospital between 2006 and 2015 were included in the study. The clinical features of patients, microbiology, and 30-day mortality were collected from the electronic medical records database and analyzed. The results showed that there were 38 patients infected by Enterococcus faecalis (E. faecalis), 24 by Enterococcus faecium (E. faecium), 1 by Enterococcus casseliflavus (E. casseliflavus), and 1 by Enterococcus gallinarum (E. gallinarum). A Charlson comorbidity score ≥5, corticosteroid treatment, placement of catheters or other prosthetic devices and history of antibiotic use were found more frequently in E. faecium BSI patients than in E. faecalis patients (P=0.017, P=0.027, P=0.008 and P=0.027, respectively). Furthermore, the univariate and multivariate analysis showed that corticosteroid treatment (OR=17.385, P=0.008), hospital acquisition (OR=16.328, P=0.038), and vascular catheter infection (OR=14.788, P=0.025) were all independently associated with 30-day mortality. Our results indicate that E. faecalis and E. faecium are two different pathogens with unique microbiologic characteristics, which cause different clinical features in BSI, and the empiric antimicrobial treatments are paramount for patients with enterococcal BSI.

Bloodstream Infections Caused by Enterococcus spp: A 10-year Retrospective Analysis at a Tertiary Hospital in China / 华中科技大学学报（医学）（英德文版）

In order to discover the risk factors for 30-day mortality in bloodstream infections (BSI) caused by Enterococcus spp.strains,we explored the clinical and therapeutic profile of patients with Enterococcus spp.BSI and the characteristics of this condition.A total of 64 patients with BSI caused by Enterococcus spp.who were treated in our hospital between 2006 and 2015 were included in the study.The clinical features of patients,microbiology,and 30-day mortality were collected from the electronic medical records database and analyzed.The results showed that there were 38 patients infected by Enterococcus faecalis (E.faecalis),24 by Enterococcus faecium (E.faecium),1 by Enterococcus casseliflavus (E.casseliflavus),and 1 by Enterococcus gallinarum (E.gallinarum).A Charlson comorbidity score ≥5,corticosteroid treatment,placement of catheters or other prosthetic devices and history of antibiotic use were found more frequently in E.faecium BSI patients than in E.faecalis patients (P=0.017,P=0.027,P=0.008 and P=0.027,respectively).Furthermore,the univariate and multivariate analysis showed that corticosteroid treatment (OR=17.385,P=0.008),hospital acquisition (OR=16.328,P=0.038),and vascular catheter infection (OR=14.788,P=0.025) were all independently associated with 30-day mortality.Our results indicate that E.faecalis and E.faecium are two different pathogens with unique microbiologic characteristics,which cause different clinical features in BSI,and the empiric antimicrobial treatments are paramount for patients with enterococcal BSI.