屎肠球菌esp和hyl基因与生物被膜形成关系的研究

The relationship between esp,hyl genes and biofilm formation in Enterococcus faecium

目的研究临床分离屎肠球菌esp、hyl基因与生物被膜形成的相关性。方法常规分离菌株,采用纸片扩散法和琼脂稀释法进行药物敏感性试验,多重PCR检测本院临床分离屎肠球菌hyl、esp基因的分布情况,微量板定量检测法和激光共聚焦显微镜分析hyl、esp基因与生物被膜形成的关系。结果 70株临床分离屎肠球菌生物被膜形成阳性率为18.6%,其中hyl基因阳性株不能形成生物被膜,esp基因阳性株生物被膜形成率为36.4%,hyl+esp阳性株生物被膜形成率为27.3%,esp基因阴性株生物被膜形成率为6%。结论本院临床分离屎肠球菌形成生物膜的能力较弱,hyl基因不能促进生物被膜的形成,esp基因能够促进生物被膜的形成,生物被膜的形成不局限于esp阳性菌株。

To investigate the relationship between esp, hyl genes and biofilm formation in clinical isolates of Enterococcusfaecium. Methods All strains of Enterococcus faecium were isolated from clinical specimens by routine method. The antimicrobial susceptibility was evaluated by disc diffusion test（Kirby--Bauer） and agar dilution test. A multiplex PCR was applied for the detection of hyaluronidase（hy/） and enterococcal surface protein（esp） gene from the First Affiliated Hospital of Chongqing Medical University between 2010.1 and 2011.12. The formation of biofilm was studied by modified microtiter plate test and confocal laser scanning microscope. Results The rate of biofilm formation of 70 isolates was 18.6%. The rate of biofilm formation of hyl, esp, hyl＋esp positive isolates were 0, 36.4% and 27.3%, respectively. The rate of biofilm formation of esp negative isolates was 6%. Conclusion Biofilm formation is not very common in clinical isolates of Enterococcus faecium from our hospital. hyl gene is not associated with biofilm formation, esp is an important factor of biofilm formation, and the ability of biofilm formation is not limited to the esp positive isolates.