Diversidade e resistência a antimicrobianos em Staphylococcus spp. isolados de cães e animais silvestres

Abstract

The genus Staphylococcus is of great relevance to human medicine and veterinary medicine and is composed of more than 75 species to date. Staphylococcus can be found as part of the natural microbiota of animals and humans, but also as an opportunistic agent in infectious processes. Because of its high capacity to acquire, harbor, and transmit antimicrobial resistance genes, this bacterial genus has great relevance in the public health scenario, and its constant monitoring is of great importance not only in human health, but also in domestic animals and wildlife, both described as an essential part of this epidemiological chain. Given the scarcity of data on the epidemiology of multidrug-resistant strains of Staphylococcus spp. in dogs in Brazil and in wild animals worldwide, the objectives of this study were: (1) to evaluate the infection/colonization dynamics, risk factors, genetic diversity, and antimicrobial resistance of S. pseudintermedius isolated from dogs in the clinic and Intensive Care Unit (ICU) environments of the Veterinary Hospital of UFMG; (2) to evaluate the occurrence, distribution, and antimicrobial resistance profile of Staphylococcus spp. in different groups of wild animals, including rodents, marsupials, coatis, canids, felids, pigeons, and tortoises. In evaluating isolates from infectious conditions in dogs, the present study showed a high frequency of multidrug-resistant staphylococci (MDR), especially methicillin-resistant S. pseudintermedius (MRSP). Isolates from surgical wound showed a higher frequency of resistance when compared to the other clinical infections studied. The MRSP isolates were allocated either within clonal complex (CC) 71, of recognized worldwide importance, or among nine new sequence types (ST) belonging to other CCs. In the study on the colonization dynamics of Staphylococcus spp. in the ICU, 21.6% of dogs with staphylococcal isolates had MRSP strains, while 5.9% had methicillin-resistant S. aureus (MRSA) strains. MRSP strains resistant to nine classes of antimicrobials, with identical resistance profiles, were observed in different animals throughout the experiment period, suggesting the possibility of a clone circulating among animals. Dogs with these strains, presumably clones, had longer hospital stays than those colonized by other MRSP strains. Acquisition of MRSP during ICU stay was associated with: sex (females), age (>7 years), and dogs that had prior antimicrobial use. In studies on distribution and resistance profile in different wild animals, all species showed antimicrobial resistant strains and, with the exception of jabutis and marsupials, all showed MDR strains. We also highlight the detection of S. intermedius and S. delphini in coatis, and S. pseudintermedius in maned wolves, suggesting two new hosts for bacteria of the S. intermedius group (SIG). New STs of S. pseudintermedius have been reported in maned wolves and showed some similarities to strains previously isolated from dogs in Brazil. The present study also reported, for the first time in the literature, S. felis in wild animals, specifically in two jaguars and one maned wolf. This work reinforces the hypothesis that dogs and wild animals may act as reservoirs and disseminators of pathogenic and multi-antimicrobial resistant staphylococci.