Genomic Features of Antimicrobial Resistance in Staphylococcus pseudintermedius Isolated from Dogs with Pyoderma in Argentina and the United States: A Comparative Study.

Staphylococcus pseudintermedius is the most common opportunistic pathogen in dogs and methicillin resistance (MRSP) has been identified as an emerging problem in canine pyoderma. Here, we evaluated the antimicrobial resistance (AMR) features and phylogeny of S. pseudintermedius isolated from canine pyoderma cases in Argentina ( n = 29) and the United States ( n = 29). 62% of isolates showed multi-drug resistance. The AMR genes found: mec A, bla Z, ermB , dfr G, cat A, tet M, aac (6')- aph (2″), in addition to tet K and lnu A (only found in U.S. isolates). Two point mutations were detected: grl A(S80I)- gyr A(S84L), and grl A(D84N)- gyr A(S84L) in one U.S. isolate. A mutation in rpo B (H481N) was found in two isolates from Argentina. SCC mec type III, SCC mec type V, ΨSCC mec 57395 were identified in the Argentinian isolates; and SCC mec type III, SCC mec type IVg, SCC mec type V, and SCC mec type VII variant in the U.S. cohort. Sequence type (ST) ST71 belonging to a dominant clone was found in isolates from both countries, and ST45 only in Argentinian isolates. This is the first study to comparatively analyze the population structure of canine pyoderma-associated S. pseudintermedius isolates in Argentina and in the U.S. It is important to maintain surveillance on S. pseudintermedius populations to monitor AMR and gain further understanding of its evolution and dissemination.