Smith Carolyne S, Parnell Peter, Hodgson Gillian, Darby Bob, Barr Ben, Tompkins David, Heritage John, Wilcox Mark H
Leeds Teaching Hospitals NHS Trust, Leeds LS1 3EX, UK.
J Antimicrob Chemother. 2008 Nov;62(5):968-72. doi: 10.1093/jac/dkn326. Epub 2008 Aug 27.
Panton-Valentine leucocidin (PVL)-positive Staphylococcus aureus are responsible for causing skin and soft tissue infections, with the potential to cause severe invasive disease. Recently, methicillin-resistant Staphylococcus aureus (MRSA) strains that produce PVL have emerged in the community. As residents of care homes are a key group at risk of MRSA colonization and infection, we have examined the epidemiology of MRSA in three large cohorts of residents in urban care homes to establish whether PVL-positive MRSA strains are present in this setting.
Nasal swabs (n = 3037) collected from consenting residents of 69 care homes in Leeds, UK, were screened for MRSA using chromogenic agar over three periods (June-August 2005, November-December 2006 and October-November 2007). PCR amplification was used to detect genes encoding PVL. Antibiogram profile and PFGE were also used to characterize MRSA isolates (n = 601).
MRSA prevalence was 21%, 20% and 19% in each cohort, respectively. The majority of the isolates were related epidemiologically to the predominant local nosocomial epidemic MRSA strain, EMRSA-15 (78%). No isolate carried the genes encoding PVL. Twelve percent of the isolates (n = 74) had increased susceptibility to non-beta-lactam agents and were distributed across 31 care homes.
MRSA strains that produced PVL were not found to be colonizing residents of care homes between 2005 and 2007. Continued surveillance is, however, necessary to understand the interaction between MRSA in care homes and hospitals, especially to reduce the chance that the former may amplify community-associated MRSA strains.
杀白细胞素（PVL）阳性的金黄色葡萄球菌可引起皮肤和软组织感染，并有引发严重侵袭性疾病的可能。近来，社区中出现了产PVL的耐甲氧西林金黄色葡萄球菌（MRSA）菌株。由于疗养院居民是MRSA定植和感染的高危人群，我们对城市疗养院中三个大型居民队列进行了MRSA流行病学调查，以确定该环境中是否存在PVL阳性的MRSA菌株。
在三个时间段（2005年6月至8月、2006年11月至12月、2007年10月至11月），使用显色琼脂对从英国利兹69家疗养院同意参与的居民中采集的鼻拭子（n = 3037）进行MRSA筛查。采用聚合酶链反应（PCR）扩增检测编码PVL的基因。还使用抗生素谱和脉冲场凝胶电泳（PFGE）对MRSA分离株（n = 601）进行特征分析。
各队列中MRSA的患病率分别为21%、20%和19%。大多数分离株在流行病学上与当地主要的医院流行MRSA菌株EMRSA - 15相关（78%）。没有分离株携带编码PVL的基因。12%的分离株（n = 74）对非β - 内酰胺类药物的敏感性增加，分布在31家疗养院。
在2005年至2007年期间，未发现产PVL的MRSA菌株定植于疗养院居民中。然而，持续监测对于了解疗养院和医院中MRSA之间的相互作用是必要的，特别是为了减少前者可能扩增社区相关MRSA菌株的机会。
