Department of Medical Microbiology, Institute of Microbiology, Rio de Janeiro Federal University, Rio de Janeiro, Brazil.
Diagn Microbiol Infect Dis. 2012 Jan;72(1):32-40. doi: 10.1016/j.diagmicrobio.2011.09.017. Epub 2011 Nov 17.
Staphylococcus epidermidis is a leading cause of hospital-acquired infections, mostly associated with the use of medical devices in seriously ill or immunocompromised patients. Currently, the characteristics of methicillin-resistant S. epidermidis (MRSE) isolates from Rio de Janeiro hospitals are unknown. In this study, staphylococcal chromosomal cassette mec (SCCmec) types, antimicrobial susceptibility profiles, biofilm formation genes, and multilocus sequence types (MLST) were investigated in 35 MRSE clinical isolates. The collection of isolates was previously well characterized by pulsed-field gel electrophoresis (PFGE) into 2 main genotypes (A and B, 22 isolates) and 10 sporadic genotypes (13 isolates). MLST revealed a total of 8 different sequence types (STs), but ST2 and ST23, which were icaAB-positive, represented the majority (71.4%) of MRSE isolates tested. Almost all isolates (91.4%) belonged to clonal complex 2. SCCmec types III and IV were identified among 71.4% of the isolates, while the remaining was nontypeable. The predominant MRSE genotypes were defined as SCCmec type III/ST2 (PFGE type A) and SCCmec type IV/ST23 (PFGE type B) isolates, which were both associated with high antimicrobial resistance and presence of biofilm-related genes.
表皮葡萄球菌是医院获得性感染的主要原因，主要与重病或免疫功能低下患者使用医疗设备有关。目前，里约热内卢医院耐甲氧西林表皮葡萄球菌（MRSE）分离株的特征尚不清楚。在这项研究中，对 35 株 MRSE 临床分离株的葡萄球菌染色体盒 mec（SCCmec）型、抗菌药物敏感性谱、生物膜形成基因和多位点序列分型（MLST）进行了研究。这些分离株的采集先前通过脉冲场凝胶电泳（PFGE）很好地分为 2 种主要基因型（A 和 B，22 株）和 10 种散发性基因型（13 株）进行了很好的特征描述。MLST 总共显示了 8 种不同的序列类型（ST），但 icaAB 阳性的 ST2 和 ST23 代表了大多数（71.4%）测试的 MRSE 分离株。几乎所有分离株（91.4%）都属于克隆复合体 2。71.4%的分离株中鉴定出 SCCmec 类型 III 和 IV，而其余的则无法分型。主要的 MRSE 基因型被定义为 SCCmec 类型 III/ST2（PFGE 型 A）和 SCCmec 类型 IV/ST23（PFGE 型 B）分离株，它们都与高抗菌药物耐药性和生物膜相关基因的存在有关。
