Use of a single-nucleotide polymorphism genotyping system to demonstrate the unique epidemiology of methicillin-resistant Staphylococcus aureus in remote Aboriginal communities
Use of a single-nucleotide polymorphism genotyping system to demonstrate the unique epidemiology of methicillin-resistant Staphylococcus aureus in remote Aboriginal communities
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DOI：
10.1128/jcm.00836-06
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发表时间：
2006-10-01
影响因子：
9.4
通讯作者：
Currie, Bart J.
中科院分区：
文献类型：
--
作者：
McDonald, Malcolm;Dougall, Annette;Currie, Bart J.
与世界其他许多地区一样，社区获得的耐甲氧西林金黄色葡萄球菌(CA-MRSA)已成为澳大利亚的一个主要公共卫生问题。据报告，土著社区的CA-MRSA皮肤和软组织感染率很高。我们使用基于多位点序列类型(MLST)数据库的单核苷酸多态性(SNP)基因分型系统，调查了澳大利亚北部三个偏远土著社区12个月来CA-MRSA和甲氧西林敏感金黄色葡萄球菌(MSSA)的流行病学。此外，还进行了潘顿-瓦伦丁杀白素(PVL)基因的实时聚合酶链式反应(RT-PCR)、葡萄球菌盒式染色体(SCCmec)分型和药敏试验。从脓皮病皮损中检出金黄色葡萄球菌221例，咽拭子检出44例。金黄色葡萄球菌从皮肤溃疡中恢复的月中位数为58%(四分位数范围为62-78%)，没有季节性变化。23%的分离株是CA-MRSA；这一比例在各个社区都是相似的，在研究期间没有变化。47%的CA-MRSA和21%的MSSA对红霉素耐药。SNP分型鉴定出14种不同的克隆性复合体，但以CC75为主，占CA-MRSA分离株的71%。利用所选菌株的另一个SNP和MLST，证实这些菌株为ST75-like。除1株外，其余cc75株均为SSCmec IV型(1株为V型)，均为PVL阴性。每月对基于SNP的cc类型的跟踪显示出一个高度动态的过程。ST75-MRSA-IV似乎是该地区独有的，可能是在偏远的土著社区从头进化而来的。
Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a major public health problem in Australia, as in many other parts of the world. High rates of CA-MRSA skin and soft tissue infection have been reported from Aboriginal communities. We used a single-nucleotide polymorphism (SNP) genotyping typing system based on the multilocus sequence type (MLST) database to investigate the epidemiology of CA-MRSA and methicillin-sensitive S. aureus (MSSA) over a 12-month period in three remote Aboriginal communities of Northern Australia. This was supplemented by real-time PCR for Panton-Valentine leukocidin (PVL) genes, staphylococcal cassette chromosome mec (SCCmec) typing, and antimicrobial susceptibility testing. S. aureus was recovered from pyoderma lesions on 221 occasions and throat swabs on 44 occasions. The median monthly recovery rate of S. aureus from skin sores was 58% (interquartile range, 62 to 78%), and there was no seasonal variation. Twenty-three percent of isolates were CA-MRSA; the proportion was similar across the communities and did not vary over the study period. Erythromycin resistance was found in 47% of CA-MRSA and 21% of MSSA. SNP-based typing identified 14 different clonal complexes (cc); however, cc75 was predominant, accounting for 71% of CA-MRSA isolates. These were confirmed as ST75-like by using an additional SNP and MLST of selected isolates. All but one of the cc75 isolates had SSCmec type IV (one had type V), and all were PVL negative. Monthly tracking of SNP-based cc types showed a highly dynamic process. ST75-MRSA-IV appears to be unique to the region and probably evolved de novo in remote Aboriginal communities.