从伊朗临床样本中分离出的肠球菌的黏附及毒力因子特性
Adhesion and virulence factor properties of Enterococci isolated from clinical samples in Iran.
作者信息
Kafil Hossein Samadi, Mobarez Ashraf Mohabati, Moghadam Mehdi Fourozandeh
机构信息
Department of Medical Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
出版信息
Indian J Pathol Microbiol. 2013 Jul-Sep;56(3):238-42. doi: 10.4103/0377-4929.120375.
INTRODUCTION
Enterococci rank among leading causes of nosocomial bacteremia, urinary tract infections and community acquired endocarditis. The aim of the present study was to investigate the presence of virulence factors in Enterococci strains isolated from clinical samples in Iranian Educational hospitals.
METHODOLOGY
Presence of aggregation substance (asa), extracellular surface protein (esp), Enterococcus faecalis antigen A (efaA), adhesin of collagen from E. faecalis (ace), endocarditis and biofilm-associated pilli (ebp) as colonization factors and cytolysin (cyl), gelatinase (gel) and hyaloronidase (hyl) as secretary factors were investigated in isolates. A total of 201 clinical isolates of Enterococci were collected in 2009-2010 from eight educational hospitals. After deoxyribonucleic acid extraction, they were examined for presence of virulence factors by polymerase chain reaction.
RESULTS
E. faecalis and Enterococcus faecium were isolated from 56.9% to 43.1%, respectively. Resistance to vancomycin and gentamicin were 33.8% and 83.9% in E. faecium isolates and 16.3% and 88.1% in E. faecalis isolates respectively. Colonization factors were found to be more prevalent in E. faecalis isolates and almost all isolates of E. faecalis had ace, ebp and efaA genes. Esp gene had a higher rate of distribution in Enterococci isolates (75.1%) in this study compared with previous studies. One of E. faecalis isolates contained hyl gene, but 38.8% of E. faecium isolates had it. Mutual exclusive were present between hyl and efaA in all E. faecium isolates and 69.7% of E. faecium hyl - positive isolates were esp positive.
CONCLUSION
According to these results, virulence genes were more prevalent in E. faecalis isolates and E. faecalis had more potential pathogenesis for initiating an infection; however because of E. faeciums higher antibiotic resistance, we have been facing higher E. faecium infections in hospitalized patients.
引言
肠球菌是医院获得性菌血症、尿路感染和社区获得性心内膜炎的主要病因之一。本研究的目的是调查从伊朗教学医院临床样本中分离出的肠球菌菌株中毒力因子的存在情况。
方法
研究了分离株中聚集物质（asa）、细胞外表面蛋白（esp）、粪肠球菌抗原A（efaA）、粪肠球菌胶原黏附素（ace）、心内膜炎和生物膜相关菌毛（ebp）作为定植因子，以及细胞溶素（cyl）、明胶酶（gel）和透明质酸酶（hyl）作为分泌因子的存在情况。2009年至2010年期间，从八所教学医院共收集了201株肠球菌临床分离株。提取脱氧核糖核酸后，通过聚合酶链反应检测它们是否存在毒力因子。
结果
粪肠球菌和屎肠球菌的分离率分别为56.9%和43.1%。屎肠球菌分离株对万古霉素和庆大霉素的耐药率分别为33.8%和83.9%，粪肠球菌分离株分别为16.3%和88.1%。发现定植因子在粪肠球菌分离株中更为普遍，几乎所有粪肠球菌分离株都有ace、ebp和efaA基因。与以往研究相比，本研究中esp基因在肠球菌分离株中的分布率更高（75.1%）。一株粪肠球菌分离株含有hyl基因，但38.8%的屎肠球菌分离株含有该基因。在所有屎肠球菌分离株中，hyl和efaA互斥，69.7%的hyl阳性屎肠球菌分离株esp阳性。
结论
根据这些结果，毒力基因在粪肠球菌分离株中更为普遍，粪肠球菌引发感染的潜在致病性更强；然而，由于屎肠球菌的抗生素耐药性更高，我们在住院患者中面临着更高的屎肠球菌感染率。
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