Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
Infect Genet Evol. 2011 Jul;11(5):1066-71. doi: 10.1016/j.meegid.2011.03.019. Epub 2011 Apr 2.
Community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is a major global problem. Healthy carriers of S. aureus strains have an important role in the dissemination of this bacterium. The aim of this study was to estimate the prevalence of S. aureus and methicillin-resistant S. aureus (MRSA) carriage among healthy children in a city of Buenos Aires province, Argentina, and to determine the potential risk factors for its acquisition. We also described the molecular features of MRSA strains circulating in this population. S. aureus carriage was investigated in all children attending the last year of kindergarten during the 2008 school- year period. Household contacts of MRSA carriers were also screened. Of 316 healthy children, 98 (31.0%) carried S. aureus, including 14 MRSA carriers (4.4%) and 84 methicillin susceptible S. aureus (MSSA) carriers (26.6%). All MRSA isolates carried the SCCmec type IV cassette. Eight of the fourteen isolates were closely related to the clone responsible for most severe community-acquired MRSA infections caused in our country (CAA: PFGE A, SCCmec IV, spa t311, ST5). Two subtypes (A(1) and A(2)) were distinguished in this group by PFGE. Both had agr type II and presented the same virulence determinants, except for PVL coding genes and sea that were only harbored by subtype A(1). Our results, based on the analysis of MRSA isolates recovered in the screening of healthy children, provide evidence of a community reservoir of the major CA-MRSA clone described in Argentina.
社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）是一个全球性的主要问题。金黄色葡萄球菌菌株的健康携带者在该细菌的传播中起着重要作用。本研究的目的是评估阿根廷布宜诺斯艾利斯省一个城市健康儿童中金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌（MRSA）携带率，并确定其获得的潜在危险因素。我们还描述了在该人群中循环的 MRSA 菌株的分子特征。在 2008 学年期间，对所有上幼儿园最后一年的健康儿童进行了金黄色葡萄球菌携带情况调查。还对 MRSA 携带者的家庭接触者进行了筛查。在 316 名健康儿童中，98 名（31.0%）携带金黄色葡萄球菌，包括 14 名 MRSA 携带者（4.4%）和 84 名耐甲氧西林金黄色葡萄球菌（MSSA）携带者（26.6%）。所有 MRSA 分离株均携带 SCCmec 型 IV 盒。14 株分离株中有 8 株与我国引起的大多数严重社区获得性 MRSA 感染相关的克隆密切相关（CAA：PFGE A、SCCmec IV、spa t311、ST5）。在该组中通过 PFGE 区分了两个亚型（A(1)和 A(2)）。这两种亚型均具有 agr 型 II，并且具有相同的毒力决定因素，除了仅由亚型 A(1)携带的 PVL 编码基因和 sea 基因。我们的研究结果基于对健康儿童筛查中回收的 MRSA 分离株的分析，为在阿根廷描述的主要 CA-MRSA 克隆的社区储库提供了证据。
