Biofilm formation and esp, gelE, ebpA genes and QS-fsr system in Enterococcus faecalis

Abstract

Objective To investigate the association of esp, gelE, ebpA and QS-fsr system and biofilm formation in Enterococcus faecalis. Methods Totally 24 isolates of Enterococcus faecalis were collected from urine and catheter of clinical urine tract infection patients in Third Xiangya Hospital from Oct. 2007 to Jun. 2008, and were divided into biofilm group and non-biofilm group. The luminance ratios of esp, gelE, ebpA and fsrrB of Enterococcus faecalis in biofilm group and non-biofilm group were detected by RT-PCR. And the expression of esp, gelE, ebpA, fsrrB genes in different groups were detected by real-time PCR and were relatively quantitated through 2-△△Ct method. Moreover, the relevancies between that fourgenes and biofilm formation in Enterococcus faecalis were analyzed respectively. Results The expression of esp and ebpA in biofilm group were 298 times and 59 times more than the non-biofilm group. The expression level ofgelE and fsrB in biofilm group were 1/244 and 1/249 times less than the non-biofilm group, and the luminance ratios of esp, gelE, ebpA and fsrB were not significant between the two groups (rank sum was 92,79, 42 and 34 respectively,all P ＞ 0. 05 ). Conclusions The results showed that the biofilm formation in Enterococcus faecalis was promoted by esp and ebpA, and was inhabited by gelE and fsrB, which suggested that the expression of esp, ebpA and gelE genes was regulated by fsr system. Key words: Enterococcus faecalis; Bacterial proteins; Fimbriae,bacterial; Biofilms; Urinary tract infections