Institute of Veterinary Bacteriology, University of Berne, Berne, Switzerland.
J Antimicrob Chemother. 2010 Jun;65(6):1145-54. doi: 10.1093/jac/dkq078. Epub 2010 Mar 25.
The aim of this study was to determine the phenotypic and genotypic resistance profiles of methicillin-resistant Staphylococcus pseudintermedius (MRSP) and to examine the clonal distribution in Europe and North America.
A total of 103 MRSP isolates from dogs isolated from several countries in Europe, the USA and Canada were characterized. Isolates were identified by PCR-restriction fragment length polymorphism (RFLP), antimicrobial susceptibility was determined by broth dilution or gradient diffusion, and antimicrobial resistance genes were detected using a microarray. Genetic diversity was assessed by multilocus sequence typing (MLST), PFGE and spa typing. Staphylococcal cassette chromosome mec (SCCmec) elements were characterized by multiplex PCR.
Thirteen different sequence types (STs), 18 PFGE types and 8 spa types were detected. The hybrid SCCmec element II-III described in a MRSP isolate was present in 75 (72.8%) isolates. The remaining isolates either had SCCmec type III (n=2), IV (n=6), V (n=14) or VII-241 (n=4) or were non-typeable (n=2). The most common genotypes were ST71(MLST)-J(PFGE)-t02(spa)-II-III(SCCmec) (56.3%) and ST68-C-t06-V (12.6%). In addition to mecA-mediated beta-lactam resistance, isolates showed resistance to trimethoprim [dfr(G)] (90.3%), gentamicin/kanamycin [aac(6')-Ie-aph(2')-Ia] (88.3%), kanamycin [aph(3')-III] (90.3%), streptomycin [ant(6')-Ia] (90.3%), streptothricin (sat4) (90.3%), macrolides and/or lincosamides [erm(B), lnu(A)] (89.3%), fluoroquinolones (87.4%), tetracycline [tet(M) and/or tet(K)] (69.9%), chloramphenicol (cat(pC221)) (57.3%) and rifampicin (1.9%).
Two major clonal MRSP lineages have disseminated in Europe (ST71-J-t02-II-III) and North America (ST68-C-t06-V). Regardless of their geographical or clonal origin, the isolates displayed resistance to the major classes of antibiotics used in veterinary medicine and thus infections caused by MRSP isolates represent a serious therapeutic challenge.
本研究旨在确定耐甲氧西林金黄色葡萄球菌（MRSP）的表型和基因型耐药谱，并研究其在欧洲和北美的克隆分布情况。
对来自欧洲、美国和加拿大多个国家的 103 株犬源 MRSP 分离株进行了特征分析。通过 PCR-限制性片段长度多态性（RFLP）鉴定分离株，采用肉汤稀释或梯度扩散法测定抗菌药物敏感性，采用微阵列检测抗菌药物耐药基因。采用多位点序列分型（MLST）、PFGE 和 spa 分型评估遗传多样性。通过多重 PCR 对葡萄球菌盒式染色体 mec（SCCmec）元件进行了特征分析。
共检测到 13 种不同的序列类型（STs）、18 种 PFGE 型和 8 种 spa 型。在 75 株（72.8%）分离株中发现了一种在 MRSP 分离株中描述的混合 SCCmec 元件 II-III。其余分离株要么具有 SCCmec 类型 III（n=2）、IV（n=6）、V（n=14）或 VII-241（n=4），要么无法定型（n=2）。最常见的基因型为 ST71（MLST）-J（PFGE）-t02（spa）-II-III（SCCmec）（56.3%）和 ST68-C-t06-V（12.6%）。除了 mecA 介导的β-内酰胺耐药外，分离株还表现出对 trimethoprim[dfr(G)]（90.3%）、gentamicin/kanamycin[aac(6')-Ie-aph(2')-Ia]（88.3%）、kanamycin[aph(3')-III]（90.3%）、streptomycin[ant(6')-Ia]（90.3%）、streptothricin（sat4）（90.3%）、大环内酯类和/或林可酰胺类[erm(B)、lnu(A)]（89.3%）、氟喹诺酮类（87.4%）、tetracycline[tet(M)和/或 tet(K)]（69.9%）、chloramphenicol（cat(pC221)）（57.3%）和 rifampicin（1.9%）的耐药。
两种主要的克隆性 MRSP 谱系已在欧洲（ST71-J-t02-II-III）和北美（ST68-C-t06-V）传播。无论其地理或克隆来源如何，分离株均对兽医临床中使用的主要类别的抗生素表现出耐药性，因此由 MRSP 分离株引起的感染是一个严重的治疗挑战。
