Frequency, Distribution, and Antimicrobial Resistance of Methicillin-Resistant Staphylococci and Mammaliicoccus sciuri Isolated from Dogs and Their Owners in Rio de Janeiro

<b>Background:</b><i>Staphylococcus</i> spp. and <i>Mammaliicoccus sciuri</i> (<i>M. sciuri</i>) are Gram-positive cocci that inhabit mammals' and birds' skin and mucous membranes, part of the microbiota. An imbalance in local immunity can increase colonization, resulting in various infections. Inappropriate use of antimicrobials leads to Staphylococci and <i>M. sciuri</i> becoming resistant to conventional treatments. The transmission of methicillin-resistant staphylococci and <i>M. sciuri</i> (MRS and MRMs, respectively) between humans and animals is still underreported in Brazil. <b>Objectives:</b> this study aimed to describe the frequency, distribution, resistance pattern, and evaluation of potential sharing of MRS and MRMs in isolates from asymptomatic dogs and their owners in Rio de Janeiro. <b>Methods:</b> Samples from 50 asymptomatic dogs and 34 from their owners were collected. Isolates were identified by mass spectrometry. The <i>mecA</i> gene was confirmed by conventional PCR. Antimicrobial activity of samples that carried the <i>mecA</i> gene was evaluated by disk diffusion method. <b>Results:</b> In this study, MRS and MRMs were analyzed in 50 dogs and their owners (34) by identifying strains carrying the <i>mecA</i> gene. A total of 185 strains were isolated. The <i>mecA</i> gene was found in 33.5% of the isolates. The most prevalent species carrying the <i>mecA</i> gene was <i>S. epidermidis</i> (33.9%). MRMs showed 14.5%. Fourteen dogs had the same strain carrying the <i>mecA</i> gene as their owners. Of these, 50% exhibited the same antimicrobial resistance pattern, determined by the disk diffusion. The highest percentage of resistance observed in the MRS isolated from dogs and the owners was to Erythromycin (51.3% and 56.5%, respectively). <b>Conclusions:</b> The presence of methicillin-resistant staphylococci is worrisome because there is the potential to transfer these strains between dogs and humans. These strains may act as a reservoir of resistance genes.