Background: High prevalence of methicillin resistance among clinical isolates of Staphylococcus pseudintermedius obtained from dogs was reported in Seoul metropolitan area, South Korea. However, no information on genetic lineage and clonal spread is currently available.

Objective: The aim is to identify the genetic diversity of methicillin-resistant or -susceptible S. pseudintermedius (MRSP and MSSP, respectively) from healthy dogs.

Animals and methods: From 119 healthy dogs, 29 isolates consisting of 20 MRSP and 9 MSSP were collected from June 2013 to February 2014. Phenotypic features, antibiogram, multilocus sequence type (MLST), Staphylococcal cassette chromosome mec (SCCmec) type and spa gene type were analyzed.

Results: MLST showed 24 sequence types (STs), including 20 new STs that were genetically distinct from the previous STs in other geographic areas. SCCmec typing revealed that all isolates had SCCmec type V, a predominant type in North America. spa gene typing was successful in only 13 isolates (10 MRSP and 3 MSSP) and revealed two known types (t02 and t06), as well as one novel type (t73).

Conclusion: Our cumulative data indicate the presence of various populations of S. pseudintermedius in clinically normal dogs in Seoul metropolitan area.

背景：在韩国首尔市，从狗中获得的伪葡萄球菌临床分离株中甲氧西林耐药性高发。但是，目前尚无有关遗传谱系和克隆传播的信息。

目的：目的是鉴定健康犬中耐甲氧西林或易感假单胞菌的遗传多样性（分别为MRSP和MSSP）。

动物和方法：从2013年6月至2014年2月，从119只健康犬中收集了29株分离物，包括20 MRSP和9 MSSP。表型特征，抗菌素，多位点序列类型（MLST），葡萄球菌盒式染色体mec（SCC mec）类型和spa基因类型进行了分析。

结果： MLST显示了24种序列类型（ST），包括20种在遗传上与其他地理区域以前的ST不同的新ST。SCC mec分型显示，所有分离株均具有SCC mec V型，这是北美的主要类型。spa基因分型仅在13个分离株（10个MRSP和3个MSSP）中成功，揭示了两种已知类型（t02和t06）以及一种新型（t73）。

结论：我们的累积数据表明，首尔市区临床正常犬中存在多种假单胞菌种群。