Multidrug resistant Staphylococcus pseudintermedius isolated from superficial bacterial folliculitis in dogs from Portugal and Spain

Published: 24th May 2018

Multidrug resistant Staphylococcus pseudintermedius isolates have been recently increasing, which is alarming and dramatically decreases antimicrobial treatment options. T he objective of this study was to evaluate the incidence of multidrug resistance (MDR) in meticillin-susceptible and resistant Staphylococcus pseudintermedius isolates (MSSP/MRSP), previously collected from dogs with superficial bacterial folliculitis (SBF) in two referral hospitals in Portugal and Spain. Sixty S. pseudintermedius isolates were tested for oxacillin susceptibility by the Kirby-Bauer technique and divided into MRSP (30/60) and MSSP (30/60). Isolates were tested for first and second tier antibiotics recommended by the Working Group of the International Society for Companion Animal Infectious Diseases (ISCAID). All MRSP exhibited resistance to amoxicillin-clavulanic acid, clindamycin and erythromycin. High resistance levels were observed to trimethoprimsulfamethoxazole (97%), tetracycline and gentamicin (87%), cefalothin and enrofloxacin (83%), pradofloxacin (80%) and minocycline (50%). Low resistance level was observed for chloramphenicol (17%), amikacin (7%) and rifampicin (7%). One MRSP was susceptible to trimethoprim-sulfamethoxazole. Sixty and 57% of MSSP were resistant to tetracycline and minocycline, respectively. Additionally, 43% of the isolates were resistant to clindamycin and erythromycin, 20% to trimethoprim-sulfamethoxazole, 7% to enrofloxacin and pradofloxacin and 3% to chloramphenicol, gentamicin and amikacin. None were resistant to amoxicillin-clavulanic acid, cefalothin and rifampicin. Most isolates were MDR (38/60). All non-MDR isolates were MSSP. Meticillin resistance was associated with MDR to other classes of antibiotics (P=0.001). Our study showed correlation between MRSP and MDR. The presence of MRSP should alert the practitioner for MDR and limited antibiotic options.

Ana Oliveira, Joana Devesa, Peter Hill, Patrícia Poeta