Detection of the international lineage ST71 of methicillin-resistant Staphylococcus pseudintermedius in two cities in Rio de Janeiro State

Abstract

Staphylococcus pseudintermedius is the main coagulase-positive staphylococci associated with canine skin/soft tissue infections (SSTI), otitis externa, and surgical site infections. The international spread of an epidemic and multiresistant lineage of methicillin-resistant Staphylococcus pseudintermedius (MRSP), the so-called European clone-displaying sequence type (ST) 71-requires attention. The first isolation of an MRSP ST71 isolate in South America was reported in Rio de Janeiro city, in 2010; however, a limited number of canine isolates were analyzed. Thus, to have a better panel of the MRSP spread in this city, we were stimulated to continue this study and search for the presence of MRSP in 282 colonized or infected dogs in the city of Rio de Janeiro. Among the MRSP isolates collected (N = 17; 6.1%), the pulsed-field gel electrophoresis (PFGE) patterns were similar to those of European clone. All 17 isolates were classified as ST71 by multilocus sequence typing (MLST). In order to assess whether isolates of MRSP ST71 may have also spread to the Rio de Janeiro state countryside, we collected samples from 124 infected dogs in the city of Campos dos Goytacazes (232 km away from Rio de Janeiro city). Our data showed the presence of ST71 lineage in one isolate among three MRSP detected. S. pseudintermedius was isolated from 40.6% of the clinical samples (N = 165/406). A relatively high incidence of methicillin resistance, detected by a PCR-based method, was found in 12.1% of the S. pseudintermedius recovered from animals (N = 20/165). The resistance profile of these isolates was similar to that described for the international ST71 strains whose genomes are publicly available in the GenBank. The prospect of ST71 isolates being resistant to virtually all antimicrobials used in veterinary medicine is alarming and should be considered a central issue considering that MRSP ST71 spreads over large geographic distances and its transmission from animals to humans.

Keywords: Canine skin infections; MRSA; MRSP; Staphylococcus aureus; Staphylococcus pseudintermedius.

Fig. 1

Resistance rates observed in the collection of isolates from this study and from international ST71 MRSP isolates whose genomes were publicly available in the NCBI database. MRSP, methicillin-resistant Staphylococcus pseudintermedius; MSSP, methicillin-susceptible Staphylococcus pseudintermedius. pen, penicillin; ery, erythromycin; cli, clindamycin; rif, rifampicin; gen, gentamicin; cip, ciprofloxacin; tet, tetracycline; sxt, sulfamethoxazole-trimethoprim. NCBI, the National Center for Biotechnology Information