Genetic and phenotypic identities of Staphylococcus coagulans isolated from pustules in dogs with superficial bacterial folliculitis

Abstract Background: Staphylococcus coagulans is the second most common isolate from skin lesions of dogs with superficial bacterial folliculitis (SBF). However, the clinical significance of S. coagulans in canine SBF remains uncertain. This study aimed to investigate the prevalence, genotypic and phenotypic diversities of S. coagulans isolated from pustules in two dogs with SBF. Results: Two dogs with SBF were included in this study. S. coagulans was isolated as the sole organism in three pustules in case #1, whereas it coexisted with S. pseudintermedius in two of seven pustules in case #2. S. pseuintermedius was the sole organism in the remaining five pustules in case #2. Whole genome sequences and antimicrobial susceptibility tests revealed that S. coagulans isolated from the same pustules exhibited identical genotypic and phenotypic profiles, indicating clonal expansion. Meanwhile, S. coagulans isolated from different pustules exhibited similar yet distinct genotypic and phenotypic profiles. Conclusions: S. coagulans with identical genetic and phenotypic profiles can be identified as the sole organism or coexist with S. pseudintermedius in the pustules of the same dogs with SBF.