Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Department of Veterinary Public Health and Pharmacology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Sri Lanka.
Vet Microbiol. 2018 Jan;213:136-141. doi: 10.1016/j.vetmic.2017.11.022. Epub 2017 Nov 21.
The presence and genetic characteristics of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in Sri Lanka was investigated to add additional insight into global spread, emergence and evolution of MRSP. A total of 234 samples from dogs visiting veterinary clinics were cultured for staphylococci and the genomes of the MRSP isolates were sequenced, to identify resistance genes, the multilocus sequence types (MLST) and spa types. From a questionnaire the history of antimicrobial treatment and patient information was obtained. S. pseudintermedius was isolated from 116/229 samples, eight of these were MRSP. Six MRSP CC45 isolates contained a pseudo-SCC element ΨSCCmec. Two isolates belonging to ST429 (CC761) and ST121 (CC121) contained novel variants of the SCCmec Type V(T) element. The elements were designated SCCmecV(T), that carried additional transposon-related genes, and SCCmecV(T) that carried a type III restriction-modification system, a type 7 ccr gene complex, and a cadA coding sequence. Thirty-seven percent of the dogs received antimicrobial treatment at the time of sampling of which four dogs were MRSP-positive. The proportion of MRSP among S. pseudintermedius is low compared to other countries, despite the fact that in Sri Lanka antimicrobials for treatment of dogs are available over the counter. Important is the finding of novel type V(T) SCCmec elements, which further underlines the high recombination frequency of SCC elements. The ΨSCCmec was found in isolates of CC45, which is the only sequence type of MRSP known to contain this pseudo-cassette.
本研究旨在调查斯里兰卡耐甲氧西林金黄色葡萄球菌（MRSP）的存在和遗传特征，以进一步了解 MRSP 在全球的传播、出现和进化。从访问兽医诊所的狗身上采集了 234 个样本进行葡萄球菌培养，并对 MRSP 分离株的基因组进行测序，以鉴定耐药基因、多位点序列分型（MLST）和 spa 型。通过问卷调查获得了抗菌治疗史和患者信息。从 229 个样本中分离出 116 个 S. pseudintermedius，其中 8 个为 MRSP。6 个 MRSP CC45 分离株含有伪 SCC 元件 ΨSCCmec。属于 ST429（CC761）和 ST121（CC121）的两个分离株含有 SCCmec 型 V(T) 元件的新型变体。这些元件被命名为 SCCmecV(T)，携带额外的转座子相关基因，和 SCCmecV(T)，携带 III 型限制修饰系统、7 型 ccr 基因复合物和 cadA 编码序列。在采样时，37%的狗接受了抗菌治疗，其中 4 只狗为 MRSP 阳性。与其他国家相比，尽管在斯里兰卡，治疗狗的抗生素可以在柜台购买，但 S. pseudintermedius 中 MRSP 的比例较低。重要的是发现了新型 V(T)SCCmec 元件，这进一步强调了 SCC 元件的高重组频率。在 CC45 的分离株中发现了 ΨSCCmec，这是唯一已知含有这种伪盒的 MRSP 序列型。
