Ira Praharaj, Sujatha Sistla, Chandra Parija Subhash
Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Indian J Pathol Microbiol. 2013 Jan-Mar;56(1):24-30. doi: 10.4103/0377-4929.116144.
Enterococci have emerged as important nosocomial pathogens and have been found to possess many virulence factors, some of which are considered very important in the pathogenesis of diseases caused by them. The following study was carried out to evaluate some of the virulence determinants elaborated by strains of enterococci in our setup and to ascertain if these strains differ considerably from commensal strains of enterococci in the expression of these virulence determinants.
One hundred and fifty-seven isolates of Enterococcus species from clinical specimens were evaluated for the presence of virulence determinants like hemolysin production, gelatinase production and biofilm formation by phenotypic tests. The presence of enterococcal surface protein (esp) gene in the isolates was detected using polymerase chain reaction (PCR). Thirty strains of Enterococcus isolated from fecal samples of patients admitted to the hospital were also tested for the presence of these virulence factors. Strains of Enterococcus from clinical specimens and those present as commensals were compared with respect to the elaboration of virulence factors using Fisher's exact test.
The association between biofilm formation and presence of the "esp" gene was not found to be statistically significant. Among the virulence determinants studied, gelatinase production and the "esp" gene were found to be significantly more common in clinical isolates than commensal strains of Enterococcus species.
Among the virulence factors, gelatinase and the "esp" gene were more common in clinical isolates than commensal strains. The association between biofilm formation and the presence of "esp" gene was not found to be statistically significant.
肠球菌已成为重要的医院病原体，并且已发现其拥有许多毒力因子，其中一些在由它们引起的疾病发病机制中被认为非常重要。开展以下研究以评估我们所研究的肠球菌菌株所产生的一些毒力决定因素，并确定这些菌株在这些毒力决定因素的表达方面是否与肠球菌的共生菌株有很大差异。
通过表型试验评估了157株从临床标本中分离出的肠球菌菌株是否存在溶血素产生、明胶酶产生和生物膜形成等毒力决定因素。使用聚合酶链反应（PCR）检测分离株中肠球菌表面蛋白（esp）基因的存在。还对从入院患者粪便样本中分离出的30株肠球菌进行了这些毒力因子的检测。使用Fisher精确检验比较了临床标本中的肠球菌菌株和作为共生菌存在的菌株在毒力因子产生方面的情况。
未发现生物膜形成与“esp”基因存在之间的关联具有统计学意义。在所研究的毒力决定因素中，发现临床分离株中明胶酶产生和“esp”基因比肠球菌的共生菌株更为常见。
在毒力因子中，明胶酶和“esp”基因在临床分离株中比共生菌株更为常见。未发现生物膜形成与“esp”基因存在之间的关联具有统计学意义。
