Staphylococcus pseudintermedius Human Infection Cases in Spain: Dog-to-Human Transmission.

Staphylococcus pseudintermedius is an opportunistic pathogen that has been identified as infectious agent or colonizer mainly in dogs. S. pseudintermedius has been also detected in humans and more specifically in people in contact with dogs. In this study, the possible S. pseudintermedius pet-to-human transmission was analyzed in four clinical human cases. Two patients were dog owners and S. pseudintermedius was also detected as colonizer in these healthy animals. S. pseudintermedius isolates from patients and dogs of the same household showed identical pulsed-field gel electrophoresis patterns, sequence types (STs), and antimicrobial resistance phenotypes and genotypes, and were methicillin susceptible. Resistance to erythromycin, clindamycin, tetracycline, trimetoprim-sulfamethoxazole, and/or ciprofloxacin was identified among S. pseudintermedius strains. The lineages ST241 and the new ST521 were detected in the strains of the two dog-owner patients, respectively. The strains from the other two patients presented two new STs, ST719 and ST720. To our knowledge, this is the first description of human infections caused by S. pseudintermedius in Spain.