The interactions between esp, fsr, gelE genes and biofilm formation and pfge analysis of clinical Enterococcus faecium strains

Abstract

Enterococcus faecium has become an increasingly important nosocomial pathogen due to formation of biofilms on several surfaces. Sixty one (61) E. faecium strains isolated from blood, urine and fecal were assessed for biofilm production, the effect of different glucose concentration on biofilm production and also the presence of esp, fsr and gelE genes. Pulsed field gel electrophoresis (PFGE) method was performed to show chromosomal similarities and also to determine correlation between biofilm formation ability and genetic identity of E. faecium strains. It was observed that glucose concentration of the medium and incubation period can affect biofilm formation of the bacteria. When tested strains were incubated in a medium containing 1% glucose for 48 h, 66.66% of urine isolates, 60.71% fecal isolates and 25% of blood isolates produced strong biofilm structures. esp-positive strains (80% of the all isolates) were also identified as strong biofilm producers compared to esp-negative isolates. As a result of PFGE analyses, isolates numbered 14 (isolated from fecal sample) and 81 (isolated from blood sample) were classified in minor group B at a level of 48% similarity. Out of these two isolates, all the isolates were included in major group A with 43% similarity level and this group was subdivided into six subgroups.

Comparison of antibiotic resistance and virulence between biofilm-producing and non-producing clinical isolates of Enterococcus faecium

“…A similar proportion was observed in Spain (75%) (Latasa et al, 2006). However, studies by other authors showed different results; in India, Italy, and Turkey, E. faecium isolates were able to produce biofilm less frequently or even could not form this structure (0%, 28.8%, and 48%, respectively) (Prakash et al, 2005;Di Rosa et al, 2006;Diani et al, 2014). These results indicate that the level of the ability to form biofilm among E. faecium, as well as the factors conducive to its formation, vary with geographic location.…”

“…Despite the fact that the biofilm-formation process has an essential impact on the course of enterococcal infections, our knowledge of the mechanisms and factors involved in this process is still insufficient (Almohamad et al, 2014). Therefore, many studies have sought to find the relation between biofilm formation and virulence genes, especially esp and gelE, among Enterococcus (Dupre et al, 2003;Dworniczek et al, 2005;Raad et al, 2005;Di Rosa et al, 2006;Heikens et al, 2007;Fisher & Philips, 2009;Diani et al, 2014). We reported that the prevalence of esp gene was higher in BIO + isolates (71.4%) than in BIOstrains (55%), but that this difference was statistically insignificant, and that many esp-positive isolates did not form biofilm.…”

“…For a long time, these infections were mostly caused by E. faecalis. In the last two decades, E. faecium has become one of the most prevalent nosocomial pathogens, increasing the total number of enterococcal infections and partially replacing E. faecalis as a cause of hospital-associated infections (Top et al, 2007;Diani et al, 2014). This change is related to the fact that E. faecium has a number of mechanisms of intrinsic resistance to cephalosporins, lincosamides, low levels of aminoglycosides, and many β-lactams (Sieńko et al, 2014).…”

“…Hyl (hyl) degrades hyaluronic acid and is associated with tissue damage (Wu et al, 2007). Esp (esp), which mediates the colonization, and GelE (gelE), a zinc metalloprotease, have been suggested to be involved in the process of biofilm formation (Di Rosa et al, 2006;Heikens et al, 2007;Fisher & Philips, 2009;Diani et al, 2014).…”

Draft Genome Sequences of Six Enterococcus faecalis Strains Isolated from Malaysian Clinical and Environmental Origins

“…E. faecalis is known to cause infections mainly due to the expression of virulence factors associated with adherence of mucosal and abiotic surfaces (1). The number of complete or draft genome sequences available for E. faecalis as of April 2017 is 503, comprising the bulk of enterococcal genome sequences available.…”