Havaei Seyed Asghar, Moghim Sharareh, Bardebari Ali Mohamadi, Narimani Tahmineh, Azimian Amir, Akbari Mojtaba
Department of Microbiology, School of Medicine, Isfahan, Iran.
Adv Biomed Res. 2013 Mar 6;2:13. doi: 10.4103/2277-9175.107962. Print 2013.
Staphylococcus aureus is a common human pathogen in community- and hospital-acquired infection, and its capsule is involved in pathogenesis. The predominance of 2 capsular polysaccharides types 5 and 8, on the surface of clinical isolates, led to the development of conjugate vaccine (Staph VAX) based on capsular polysacchrides types 5 and 8 conjugated to a carrier protein. The aim of this study was to determine the prevalence of capsular polysaccharides types 5 and 8 Staphylococcus aureus strains among isolates and their comparison with respect to methicillin resistance.
We studied the capsular genotypes of 193 isolates that encompassed both hospital- and community-acquired infection in Al-Zahra Hospital of Isfahan city from 2008 to 2009. Cap5 and 8 genes were detected by PCR method. Methicillin resistance was determined by PCR (mecA) and disk diffusion methods as well.
In this population (193 cases), most of the clinical isolates (73%) expressed capsular polysaccharide type 5 (24%) and 8 (49%), whereas 27% were non-typeable. The prevalence of MRSA in type 8 was 67.9%, whereas MRSA isolates in the capsular genotype 5 were 22.2%.
This study Staphylococcus aureus confirms that the prevalence of capsular polysaccharide types (5 and 8) are predominant, and Staphylococcus aureus type 8 is more resistant to methicillin compared to type 5.
金黄色葡萄球菌是社区和医院获得性感染中常见的人类病原体，其荚膜与发病机制有关。临床分离株表面两种主要的荚膜多糖类型5和8，促使了基于与载体蛋白偶联的荚膜多糖类型5和8的结合疫苗（葡萄球菌疫苗）的研发。本研究的目的是确定分离株中荚膜多糖类型5和8的金黄色葡萄球菌菌株的流行情况，并比较它们对甲氧西林的耐药性。
我们研究了2008年至2009年在伊斯法罕市扎赫拉医院收集的193株涵盖医院和社区获得性感染的分离株的荚膜基因型。通过PCR方法检测Cap5和8基因。甲氧西林耐药性也通过PCR（mecA）和纸片扩散法确定。
在这193例样本中，大多数临床分离株（73%）表达荚膜多糖类型5（24%）和8（49%），而27%无法分型。8型中耐甲氧西林金黄色葡萄球菌（MRSA）的患病率为67.9%，而荚膜基因型5中的MRSA分离株为22.2%。
本研究证实金黄色葡萄球菌中荚膜多糖类型（5和8）的流行率较高，并且8型金黄色葡萄球菌比5型对甲氧西林更耐药。
