MRSA杀白细胞素基因检测和SCCmec分子流行病学调查  

Leukocidin prevalence and molecular epidemiology of methicillin-resistant Staphylococcus aureus

作　　者：张泓[1] 李万华[1] 蔡琴[1] 韩立中[2] 张一博[2] 

机构地区：[1]上海交通大学附属儿童医院检验科,200040 [2]上海交通大学医学院附属瑞金医院

出　　处：《中国感染与化疗杂志》2009年第4期248-251,共4页Chinese Journal of Infection and Chemotherapy

摘　　要：目的了解我院临床分离的耐甲氧西林金葡菌(MRSA)葡萄球菌染色体mec基因盒(sta phyloccoccal cassette chromosomemec,SCCmec)的分布和杀白细胞毒素(Panton-Valentine Leukocidin,PVL)基因的携带状况。方法收集我院2005年10月—2006年6月从临床标本中分离的30株MRSA(mecA基因阳性)。运用多重PCR检测SCCmec的基因型和亚型;PCR扩增PVL基因;纸片扩散法检测MRSA对10种抗菌药物的耐药性。结果30株MRSA中,SCCmecⅡ型6株(20.0%);SCCmecⅢ型15株(50.0%);SCCmecⅣa型1株和SCCmecⅤ型2株。6株MecA基因阳性菌株未能分型。PVL总阳性率36.7%(1 1/30),其中SCCmecⅡ1株、SCCmecⅢ5株、SCCmecⅣa 1株,SCCmecⅤ2株、未分型2株。SCCmecⅡ型和SCCmecⅢ型菌株除对β内酰胺类抗生素耐药以外,对其他抗菌药物呈现多重耐药。SCCmecaⅣa和SCCmecⅤ型的菌株除对β内酰胺类抗生素耐药以外,对其他类抗菌药物均敏感。结论我院临床分离MRSA的SCCmec型别主要以SCCmecⅢ和SCCmecⅡ为主;PVL基因的阳性率较高;携带SCCmecⅡ和SCCmecⅢ的MRSA对抗菌药物呈现多重耐药现象。Objective Methicillin-resistant Staphylococcus aureus （MRSA） is a growing public health concern that has been associated with pediatric fatalities. This study investigated the genotypes of staphylococcal cassette chromosomal mec （SCCrnec） and Panton-Valentine Leukocidin （PVL） in MRSA strains isolated from Shanghai Children＇s Hospital by PCR. Methods A total of 30 strains of MRSA were isolated from various clinical specimens from October 2005 to June 2006. The antimicrobial susceptibility was measured by agar diffusion method. SCCmec typing was conducted using a novel multiplex PCR assay allowing for concomitant detection of methicillin resistance （mecA gene） to facilitate detection and classification of all currently described SCCmec types Ⅰ, Ⅱ , Ⅲ , Ⅳa, b, c, d andV. PVL gene was also determined by PCR. Results mecA gene was positive in all the strains. SCCmecⅡ was identified in 6（20.0%） isolates, SCCmecⅢ in 15（50.0%） isolates, SCCmecⅤ in 2 and SCCmecⅣ a in 1 isolate. Six MRSA strains were non-typeable. The isolates with SCCmec Ⅱ or SCCmecⅢ were resistant to multiple anti biotics. The strains harboring SCCrnecⅣ a or SCCmec Ⅴ were susceptible to all antibiotics except β-1actams. Eleven （36.7 %） isolates were PVL positive. The genotypes and subgenotypes of staphylococcal chromosomal cassette mec of eleven PVL-positive MRSA were SCCmecⅡ （1 isolates）, SCCmecⅢ （5 isolates）, SCCmecⅣa （1 isolate）, SCCrnecV （2 iso-Lates） non-typeable （2 isolates）. Conclusions SCCmec Ⅱ and SCCmecⅢ are the major genotypes of MRSA in our hospital. These isolates are multi-resistant to antibiotics. The prevalence of PVL gene is higher in SCCmec Ⅱ- or SCCme Ⅲ positive MRSA. The isolates with SCCrnec Ⅱ or SCCrnecⅢ were resistant to multiple antibiotics.

关 键 词：耐甲氧西林金黄色葡萄球菌 葡萄球菌染色体mec基因盒 杀白细胞毒素基因 多重聚合酶链反应 

分 类 号：R181.3[医药卫生—流行病学]