mcr-1-carrying Enterobacteriaceae isolated from companion animals in Brazil

Abstract

Plasmid-mediated polymyxin resistance was first described in 2015, in China, in Escherichia coli carrying the mcr-1 (Mobile Colistin Resistance-1) gene. Since then, it has become a major public health challenge worldwide, representing a major threat to human and animal health. In addition, there are still few reports on the prevalence of mcr-1 in Enterobacteriaceae isolated from humans, animals and food. Therefore, the purpose of the study was to investigate the occurrence of the mcr-1 gene in bacterial isolates with phenotypic resistance to polymyxin B obtained from clinical specimens of companion animals. Phenotypic resistance to polymyxin B were determined by broth microdilution and the susceptibility profile to other antimicrobials (amikacin, amoxicillin/clavulanate, ampicillin, ampicillin/sulbactam, aztreonam, cefazolin, cefepime, cefotaxime, cefoxitin, ceftazidime, ceftriaxone, chloramphenicol, ciprofloxacin, doxycycline, ertapenem, gentamicin, imipenem, marbofloxacin, meropenem, phosphomycin, piperacillin/tazobactam, tetracycline, ticarcillin/clavulanate, tobramycin and trimethoprim/sulfamethoxazole) by disc-diffusion agar method. The extraction of bacterial DNA was performed via heat shock followed by spectrophotometric evaluation. To verify the presence of mcr-1, the Polymerase Chain Reaction was employed using specific primers, followed by agarose gel electrophoresis. The positive isolates had the corresponding amplicons sequenced. In this study, there were identified the first isolates of Escherichia coli, Klebsiella spp. and Enterobacter spp. carrying the mcr-1 gene derived from specimens of companion animals in Brazil. Our results suggest the dissemination of resistance to polymyxins in the community and the environment, highlighting the need for surveillance and optimized treatment guidelines.

mcr-mediated colistin resistance in South America, a One Health approach: a review

“…carrying the mcr-1 gene derived from specimens of companion animals (dogs and cats) in Brazil. A total of 64 bacterial isolates, 3 (4.7%) bacterial isolates all derived from dogs, were positive for the mcr-1 gene [76].…”

Screening of Colistin-Resistant Bacteria in Domestic Pets from France

“…Colistin-resistance genes have also recently been detected in dogs in South Korea [ 23 ]. Further studies have assessed the occurrence of mcr-1 and mcr-2 producing Enterobacteriaceae in cats and other companion animals in Switzerland as well as other countries [ 24 , 43 , 44 , 45 , 46 , 47 ]. For the first time in France, we reported colistin-resistant bacteria carrying mcr genes in pets, although we cannot state if colistin resistance comes from contact with humans, food contamination, illegal colistin use, or environmental factors.…”

Mobile Colistin Resistance (mcr) Genes in Cats and Dogs and Their Zoonotic Transmission Risks

“…In 2020, a Brazilian study described the isolation of mcr-1-positive E. coli, Enterobacter sp., and Klebsiella sp. from clinical samples [93]. Furthermore, mcr-1 and mcr-3.7 were detected in a single E. coli ST132 isolated from a fecal sample in China.…”