<p>Genomic Analyses of Multidrug-Resistant Staphylococcus Pseudintermedius from Dogs Reveal Implications for Zoonotic Transmission Potential</p>

Staphylococci are commensal and opportunistic bacteria in humans and animals. The emergence of multidrug-resistant (”superbug”) staphylococci poses a growing threat to both veterinary and public health worldwide. In this study, two multidrug-resistant Staphylococcus pseudintermedius (S. pseudintermedius) isolates, RB10.2 and SB24, obtained from diseased dogs in Vietnam, were subjected to draft whole-genome sequencing and comparative genomic analysis. Draft genome sizes ranged from 2,635,269 bp (SB24) to 2,670,853 bp (RB10.2), with an average GC content of approximately 37.35%. Each genome contained more than 23 antibiotic resistance genes. Additionally, 20 virulence genes were identified, including those encoding intercellular adhesin, lipase, thermonuclease, adenosine synthase A, capsular polysaccharide synthesis, enterotoxins A and C, leukotoxins D and E, and lipoproteins involved in host cell entry and diacylglyceryl transferase. Multilocus sequence typing based on the PubMLST database identified RB10.2 as sequence type (ST) 733, while SB24 represented a novel ST, designated ST2738. A minimal spanning tree constructed from 781 publicly available S. pseudintermedius genomes revealed that ST733 (RB10.2) is closely related to ST551, while the novel ST2738 (SB24) is genetically linked to ST755. Both isolates showed phylogenetic relatedness to strains of canine and human origin. This study provides the first genomic insights into multidrug-resistant S. pseudintermedius from dogs in Vietnam and highlights the emergence of potentially zoonotic lineages, underscoring the need for enhanced surveillance of antimicrobial resistance and interspecies transmission.