Brief communication: Carrier rate, antimicrobial resistance and molecular typing of Staphylococcus aureus and Staphylococcus pseudintermedius in healthy dogs from Morogoro, Tanzania.

Background: Staphylococcus pseudintermedius and S. aureus are important pathogens in dogs. This study established carrier rates, strain diversity and antimicrobial resistance of these bacteria among healthy dogs in Tanzania.

Results: Based on cultures of mouth and perineal swabs, 11.3% and 50.3% of 151 healthy dogs were carriers of S. aureus and S. pseudintermedius, respectively. Only four dogs (3%) carried meticillin-resistant S. aureus (MRSA), while none of the S. pseudintermedius strains were meticillin-resistant. 12 of 19 S. aureus strains tested were resistant to penicillin G, and resistance to enrofloxacin and tetracycline was also commonly detected. The most common resistances in 103 S. pseudintermedius strains tested were to penicillin G (28.2%) and tetracycline (22.3%). S. pseudintermedius strains showed 65 different random amplified polymorphic DNA (RAPD) fingerprints, and S. aureus strains belonged to eight different spa types, including two novel types (t18988 and t18989). MRSA strains carried SCCmec type V.

Conclusions and clinical relevance: Healthy dogs in Tanzania were carriers of MRSA at low frequency, and half of the dogs carried S. pseudintermedius with high strain diversity.