Frequência de Staphiloccocus spp e perfil de sensibilidde antimicrobiana em cães portadores de otite externa

Abstract

Staphylococci are commonly isolated from the skin of healthy dogs, but they may become opportunistic pathogens with high antimicrobial resistance. As the ear is an extension of the skin, large number of cases of otitis externa are associated with this microorganism. There are several factors related to staphylococcal virulence, the most important is methicillin resistance, that is expressed by the mecA gene , which also confers resistance to other -lactams antimicrobials. Due to the phenotypic similarities among S. pseudintermedius, S intermedius and S. delphini, these microorganisms were grouped in the Staphylococcus intermedius group (SIG), which can be differentiated only through phylogenetic analysis. In order to assess the frequency of Staphylococcus spp. in dogs with ear infections and their resistance against antimicrobial agents, bilateral samples from 63 affected dogs were collected, bacteriological culture were performed, as well as phenotypic identification for isolation of Staphylococcus spp. and antibiogram. The samples were identified as belonging to SIG were subjected to PCR to molecular identification of the species S. pseudintermedius and presence of the mecA gene. From all the isolates, 54.3% of microorganisms belonging to the SIG were isolated, were all confirmed by PCR as Staphylococcus pseudintermedius. Microorganisms carrying the mecA gene performed a total of 35.8%. The increasing frequencies of isolates of Staphylococcus pseudintermedius show the need for more detailed diagnosis as well as the warning of the indiscriminate use of antibiotics.