尼日利亚三级医院金黄色葡萄球菌分离株中毒力基因与mecA基因的关联
Association of virulence genes with mecA gene in Staphylococcus aureus isolates from Tertiary Hospitals in Nigeria.
作者信息
Alli Oyebode Armstrong Terry, Ogbolu David O, Shittu Adebayo O, Okorie Anthony N, Akinola John O, Daniel John B
机构信息
Department of Biomedical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Osogbo Campus, Nigeria.
出版信息
Indian J Pathol Microbiol. 2015 Oct-Dec;58(4):464-71. doi: 10.4103/0377-4929.168875.
INTRODUCTION
Staphylococcus aureus is the etiological agent for a wide range of human infections, and its pathogenicity largely depends on various virulence factors associated with adherence, evasion of the immune system and damage of the host. This study determined the prevalence of methicillin-resistant S. aureus (MRSA) and some selected virulence genes in clinical isolates of S. aureus from South-Western Nigeria.
MATERIALS AND METHODS
The antibiotic susceptibility of 156 S. aureus isolates to various antibiotics was determined. Moreover, polymerase chain reaction detection of the mecA gene was performed including SCCmec typing, and the isolates were screened for selected genes (alpha hemolysin [hla], intracellular adhesion A [icaA], Panton-Valentine leukocidin [PVL], fibronectin binding protein A [fnbA], bone sialoprotein binding protein [bbp], exfoliative toxin A [eta], exfoliative toxin B [etb], and collagen binding adhesion [cna]) associated with virulence.
RESULTS
The prevalence of mecA gene was 42.3% (66 out of 156 S. aureus), and SCCmec typing showed that 24 (36.4%) carried the SCCmec II element, 4 (6.1%) with type III, 10 (15.2%) with SCCmec IV, and 28 (42.4%) harbored type V. The proportion of S. aureus with the following genes was ascertained: Hla (55.1%), icaA (42.3%), PVL (34.6%), fnbA (8.3%), bbp (4.5%), and eta (3.8%). All the isolates were etb and cna negative. The prevalence of the PVL gene in methicillin susceptible Staphylococcus aureus (MSSA) was 53.3% compared with 9.1% of MRSA. An association between virulence genes (eta and icaA) and mecA positive S. aureus; and significant difference in the distribution of virulence genes in in-patients and out-patients were found. The MRSA strains in South-Western Nigeria were dominated by SCCmec II and SCCmec V.
CONCLUSION
The study concluded that there is a high prevalence of MRSA in Nigeria with association of eta and icaA genes with mecA gene in S. aureus isolates.
引言
金黄色葡萄球菌是多种人类感染的病原体，其致病性很大程度上取决于与黏附、逃避免疫系统及宿主损伤相关的各种毒力因子。本研究确定了尼日利亚西南部金黄色葡萄球菌临床分离株中耐甲氧西林金黄色葡萄球菌（MRSA）及一些选定毒力基因的流行情况。
材料与方法
测定了156株金黄色葡萄球菌分离株对多种抗生素的药敏性。此外，进行了mecA基因的聚合酶链反应检测，包括SCCmec分型，并对分离株进行选定基因（α溶血素[hla]、细胞内黏附素A[icaA]、杀白细胞素[PVL]、纤连蛋白结合蛋白A[fnbA]、骨唾液蛋白结合蛋白[bbp]、剥脱毒素A[eta]、剥脱毒素B[etb]和胶原结合黏附素[cna]）的毒力相关筛查。
结果
mecA基因的流行率为42.3%（156株金黄色葡萄球菌中有66株），SCCmec分型显示24株（36.4%）携带SCCmec II元件，4株（6.1%）为III型，10株（15.2%）为SCCmec IV型，28株（42.4%）为V型。确定了携带以下基因的金黄色葡萄球菌比例：Hla（55.1%）、icaA（42.3%）、PVL（34.6%）、fnbA（8.
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