Antimicrobial resistance in Staphylococcus pseudintermedius isolated from dogs in Argentina.

COLOMBATTI OLIVIERI, M. ALEJANDRA; MAS, JAVIER; MOREIRA, JEREMIAS; SMITH, VIRGINIA; SREDNICK, MARIELA

Buenos Aires (virtual)

Congreso; World Microbe Forum 2021; 2021

American Society for Microbiology

Background: Staphylococcus pseudintermedius, is the most common opportunistic pathogen in dogs. In this host it is frequently associated with pyoderma, infections urinary tract, wounds, and otitis externa.Methicillin resistance in S. pseudintermedius isolates (MRSP) is predominantly due to the mecA gene, which encodes a protein (PBP2a) with low affinity for beta-lactam antibiotics. The incidence of MRSP has increased significantly worldwide and has emerged as an important problemdue to multidrug resistance (MDR) and the limited number of drugs remaining to treat infections caused by this organism in addition to the potential risk of zoonotic transmission.The objective of this study was to determine the antimicrobial susceptibility profiles and resistance genes in MRSP isolated from clinical samples of dogs in the region of Buenos Aires, Argentina.MethodsA total of n=95 coagulase-positivestaphylococci (CPS) isolates from clinical samples of dogs from a veterinary diagnostic laboratory in Buenos Aires, Argentina were identified by standard biochemical tests and molecular test determining the nuc gene.Antimicrobial susceptibility testing was performed by disk diffusion method using penicillin (PEN), oxacillin (OXA), cefoxitin (FOX), clindamycin (CLI), erythromycin (ERY),ciprofloxacin (CIP)(CLSI, 2013)with the addition of gentamicin (GEN), rifampicin (RIF), chloramphenicol (CLO), tetracycline (TET), doxacycline (DO) and trimethoprim/sulfamethoxazole (TMS) inMRSPisolates (CLSI,2017). D-test was performed to determine inducible resistance to clindamycin (MLSi).Detection of the mecA, blaZ, ermB, ermCand mrsAgenes were performed by PCR.ResultsAmong the totalCPS clinical isolates, n=88 were identifiedin the S. intermedius group, and a total ofn=41 (n=26 from skin, n=7 from urinary tract, n=8 from other sites)were identified as MRSP. Among the MRSP, n=38 (92.7%) presented MDR. The most frequently antimicrobial resistanceprofile was: PEN, OXA, CIP, CLI, ERY, TMS in 16 (39%) isolates, and 1 of them showed inducible resistance to clindamycin. All MRSP isolates were positive to mecA, blaZ and ermB genes.ConclusionsMRSP represent a potential theat on veterinary and public health. Clindamycin is one of the important alternative antibiotics to treat MR Staphylococci. In our study half of the MRSP isolates showed MLSi. This information will improve our understanding of the growing prevalence of resistance that severely compromises the therapeutic arsenal available and infection control strategies.