Methicillin-resistant Staphylococcus pseudintermedius isolated from canine pyoderma in North China

Aims: To determine the prevalence of carriage of methicillin-resistant Staphylococcus pseudintermedius (MRSP) among dogs with pyoderma from two small animal hospitals in North China during a 21-month period and to characterize these isolates. Methods and Results: Swabs were taken from 260 dogs with pyoderma, and the staphylococcal species isolated and methicillin resistance were confirmed phenotypically and genotypically. The identified MRSP isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal cassette chromosome (SCC) mec typing, testing for susceptibility to nine antimicrobial agents and SmaI-digested pulsed-field gel electrophoresis. Thirty-three (12.7%) dogs were positive for MRSP. The most prevalent genotypes detected among MRSP were ST71(MLST)-t06(spa)-II-III(SCCmec) (n = 22, 66 7%), followed by ST5-t19 (n = 8, 24 2%), ST126-III(n = 2, 6 1%) and ST6-t02-V (3.0%). All MRSP isolates showed extended resistance to tested antimicrobial agents. Eight different SmaI patterns were observed in 21 typeable MRSP isolates. Conclusions: Clinical isolates of MSRP isolated from dogs in North China belonged to two major clonal lineages ST71 and ST5. Significance and Impact of the Study: This study is the first report on MRSP from canine pyoderma in China. Further surveillance study is needed to gain more detailed data concerning this major clinical challenge in veterinary medicine.