RESUMO
The incidence of infections caused by resistant Gram-negative pathogens has become a critical factor in public health due to the limitation of therapeutic options for the control of infections caused, especially, by Enterobacteriaceae (Escherichia coli and Klebsiella pneumoniae), Pseudomonas spp., and Acinetobacter spp. Thus, given the increase in resistant pathogens and the reduction of therapeutic options, polymyxins were reintroduced into the clinic. As the last treatment option, polymyxins were regarded as the therapeutic key, since they were one of the few classes of antimicrobials that had activity against multidrug-resistant Gram-negative bacilli. Nonetheless, over the years, the frequent use of this antimicrobial has led to reports of resistance cases. In 2015, mcr (mobile colistin resistance), a colistin resistance gene, was described in China. Due to its location on carrier plasmids, this gene is characterized by rapid spread through conjugation. It has thus been classified as a rising threat to public health worldwide. In conclusion, based on several reports that show the emergence of mcr in different regional and climatic contexts and species of isolates, this work aims to review the literature on the incidence of the mcr gene in Brazil in different regions, types of samples identified, species of isolates, and type of carrier plasmid.
Assuntos
Colistina , Proteínas de Escherichia coli , Colistina/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Brasil/epidemiologia , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Polimixinas/uso terapêutico , Proteínas de Escherichia coli/genética , Plasmídeos/genética , Testes de Sensibilidade MicrobianaRESUMO
Emergence of colistin-resistant bacteria harboring mobile colistin resistance genes (mcr genes) pose a threat for food-producing animals and humans. In this article, we aim to highlight the emergence of Escherichia fergusonii as an important new reservoir to mcr-1-harboring plasmid in poultry production. Three strains closely related were isolated from cloacal swabs. Their genome contains four plasmids, including a 182,869 bp IncHI2 plasmid harboring the colistin resistance gene mcr-1. These results will contribute to our understanding of plasmid-mediated mcr-1 gene presence and transmission in E. fergusonii.
Assuntos
Antibacterianos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia/efeitos dos fármacos , Escherichia/genética , Genes Bacterianos/genética , Proteínas de Bactérias , Brasil , PlasmídeosRESUMO
A systematic review was performed in order to integrate and synthesize available information on mcr genes dissemination in Latin America. Four databases were searched for articles reporting plasmid-mediated colistin resistance between bacteria isolated from countries of Latin America and the Caribbean. Abstract books of scientific events realized in each region were also examined. After search and selection, 48 studies that included 18,705 isolates recovered between 2000 and 2018 were evaluated. The overall frequency of mcr genes in Latin America was 2.9% (550/18,705), with IncX4 plasmids shown to be the key vectors responsible for the dissemination of genes within the continent. Brazil, Bolivia and Argentina were the countries with the highest number of mcr-positive isolates, and only Colombia (mcr-5) and Brazil (mcr-3) presented mcr genes other than type 1. Escherichia coli, Klebsiella pneumoniae, and Salmonella enterica serovar Typhimurium were mainly found to carry the gene within the continent and these microorganisms showed high susceptibility to ertapenem, meropenem, piperacillin/tazobactam, fosfomycin and tigecycline. This review showed that the mcr gene is circulating in several countries of Latin America. Thus, it is important to encourage microbiological and molecular surveillance programs to avoid the spread of these genes within and outside the continent.