Havaei Seyed Asghar, Poursina Farkhondeh, Ahmadpour Maryam, Havaei Seyed Roholla, Ruzbahani Meisam
Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Department of Endodontics, School of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran.
Adv Biomed Res. 2017 Jul 28;6:93. doi: 10.4103/2277-9175.211798. eCollection 2017.
Panton-Valentine leukocidin (PVL) is a gamma-toxin produced by encoded by genes with several single-nucleotide polymorphisms. A mutation at nucleotide position 527 results in substitution of histidine (H) to arginine (R) at amino acid 176. The groups defined based on the amino acid change, the "R isoform" group and the "H isoform" group. The purpose of this study was to determine the frequency of PVL gene isoforms in strains isolated from patients at Al-Zahra Hospital Isfahan and molecular characterization of PVL-positive methicillin-resistant (MRSA) strains including the detection of mecA gene and staphylococcal chromosomal cassette mec (SCCmec) typing.
In this study, 130 isolates of were collected from Al-Zahra Hospital. The PVL gene identified using polymerase chain reaction (PCR); PCR products were sequenced to identify the type of isoform. The molecular characterization of isolates of PVL-positive MRSA including detection of mecA gene by PCR and also SCCmec typing was performed by multiplex PCR.
Out of 130 isolates, 23% were positive for the presence of PVL genes. The PVL positive isolates were comprised 37% (11/30) of methicillin-resistant isolates and 63% (19/30) of methicillin-susceptible (MSSA) isolates. The results showed that 17 isolated carrying isoform H and 13 isolated carrying the R isoform.
The PVL gene was predominantly found in MSSA isolates. There was no relation between PVL isoforms and the presence of mecA and SCCmec types.
杀白细胞素（PVL）是一种由基因编码产生的γ毒素，该基因存在多个单核苷酸多态性。核苷酸位置527处的突变导致氨基酸176位的组氨酸（H）被精氨酸（R）取代。根据氨基酸变化定义了“R异构体”组和“H异构体”组。本研究的目的是确定从伊斯法罕扎赫拉医院患者中分离出的菌株中PVL基因异构体的频率，以及PVL阳性耐甲氧西林金黄色葡萄球菌（MRSA）菌株的分子特征，包括检测mecA基因和葡萄球菌染色体盒式mec（SCCmec）分型。
在本研究中，从扎赫拉医院收集了130株金黄色葡萄球菌分离株。使用聚合酶链反应（PCR）鉴定PVL基因；对PCR产物进行测序以鉴定异构体类型。通过PCR检测mecA基因以及通过多重PCR进行SCCmec分型，对PVL阳性MRSA分离株进行分子特征分析。
在130株分离株中，23%的菌株PVL基因呈阳性。PVL阳性分离株包括37%（共11/30）的耐甲氧西林分离株和63%（共19/30）的甲氧西林敏感金黄色葡萄球菌（MSSA）分离株。结果显示，17株携带H异构体，13株携带R异构体。
PVL基因主要存在于MSSA分离株中。PVL异构体与mecA和SCCmec类型的存在之间没有关联。
