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

Abstract

<i>Staphylococcus pseudintermedius</i> 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 <i>S. pseudintermedius</i> isolated from canine pyoderma cases in Argentina (<i>n</i> = 29) and the United States (<i>n</i> = 29). 62% of isolates showed multi-drug resistance. The AMR genes found: <i>mec</i>A, <i>bla</i>Z, <i>ermB</i>, <i>dfr</i>G, <i>cat</i>A, <i>tet</i>M, <i>aac</i>(6')-<i>aph</i>(2″), in addition to <i>tet</i>K and <i>lnu</i>A (only found in U.S. isolates). Two point mutations were detected: <i>grl</i>A(S80I)-<i>gyr</i>A(S84L), and <i>grl</i>A(D84N)-<i>gyr</i>A(S84L) in one U.S. isolate. A mutation in <i>rpo</i>B (H481N) was found in two isolates from Argentina. SCC<i>mec</i> type III, SCC<i>mec</i> type V, ΨSCC<i>mec</i>₅₇₃₉₅ were identified in the Argentinian isolates; and SCC<i>mec</i> type III, SCC<i>mec</i> type IVg, SCC<i>mec</i> type V, and SCC<i>mec</i> 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 <i>S. pseudintermedius</i> isolates in Argentina and in the U.S. It is important to maintain surveillance on <i>S. pseudintermedius</i> populations to monitor AMR and gain further understanding of its evolution and dissemination.