RESUMO
The overuse of antimicrobials in poultry has led to the development and dissemination of multidrug-resistant bacteria in the poultry industry. One of the most effective mechanisms of resistance found in Escherichia coli is the production of extended-spectrum ß-lactamases (ESBL); there are several ESBLs, including the TEM, SHV, and CTX-M families. This resistance mechanism and the risks associated with transmitting these resistant microorganisms between animals, the environment, and humans can occur through direct contact and consumption of infected animals. This study aimed to determine the prevalence of E. coli in samples isolated from three broiler farms in Rio de Janeiro, Brazil, and screen the isolates for ESBL genes. The findings of this study demonstrated the presence of ESBL-producing E. coli in all farms studied. The findings of this study highlight the urgency for a program to monitor the poultry industry value chains at the regional level to control the spread of antimicrobial resistance. Therefore, we recommend that the enzyme subtypes produced by bacterial isolates should be determined to effectively characterize the distribution of genes related to antimicrobial resistance.
O uso excessivo de antimicrobianos em frangos de corte tem contribuído para o desenvolvimento e disseminação de bactérias multirresistentes, e um dos mais relevantes mecanismos de resistência encontrados em Escherichia coli é a produção de enzimas denominadas ß-lactamases de espectro estendido (ESBL). CTX-M, SHV e TEM são as ß-lactamases mais comumente encontradas nesta espécie e as ESBL mais prevalentes globalmente. Esse mecanismo de resistência e o risco associado à transmissão desses microrganismos resistentes entre animais, meio ambiente e seres humanos se devem principalmente ao contato direto e ao consumo de origem animal. Este trabalho buscou elucidar a prevalência de E. coli em amostras de três granjas de frangos de corte localizadas no Rio de Janeiro, Brasil, e caracterizá-las de acordo com seu genótipo. O estudo demonstrou uma presença consistente de E. coli produtora de ESBL com presença abundante do gene bla SHV nos isolados de todas as fazendas estudadas. Deste modo, este estudo teve como objetivo contribuir com dados epidemiológicos relativos à distribuição de genes relacionados às ß-lactamases na produção animal, conscientizando sobre a transmissão desses microrganismos resistentes entre animais, meio ambiente e seres humanos contribuindo com dados epidemiológicos e de sua importância em uma perspectiva de saúde única.
RESUMO
Colisitin-associated resistance in bacteria of food producing animals has gained significant attention with the mcr gene being linked with resistance. Recently, newer variants of mcr have emerged with more than nine variants currently recognized. Reports of mcr associated resistance in Escherichia coli of poultry appear to be relatively limited, but its prevalence requires assessment since poultry is one of the most important and cheapest sources of the world's protein and the emergence of resistance could limit our ability to treat disease outbreaks. Here, 107 E. coli isolates from production poultry were screened for the presence of mcr 1-9. The isolates were collected between April 2015 and June 2016 from broiler chickens and free-range layer hens in Rio de Janeiro, Brazil. All isolates were recovered from the trachea and cloaca of healthy birds and an additional two isolates were recovered from sick birds diagnosed with colibacillosis. All isolates were screened for the presence of mcr-1 to 9 using PCR and Sanger sequencing for confirmation of positive genes. Additionally, pulse field gel electrophoresis (PFGE) analysis, avian fecal E. coli (APEC) virulence associated gene screening, plasmid replicon typing and antimicrobial resistance phenotype and resistance gene screening, were also carried out to further characterize these isolates. The mcr-1 gene was detected in 62 (57.9%) isolates (61 healthy and 1 APEC) and the mcr-5 gene was detected in 3 (2.8%) isolates; mcr-2, mcr-3, mcr-4, mcr-6, mcr-7, mcr-8, and mcr-9 were not detected in any isolate. In addition, mcr 1 and 5 positive isolates were phenotypically resistant to colistin using the agar dilution assay (> 8ug/ml). PFGE analysis found that most of the isolates screened had unique fingerprints suggesting that the emergence of colistin resistance was not the result of clonal dissemination. Plasmid replicon types IncI2, FIB, and B/O were found in 38, 36, and 34% of the mcr positive isolates and were the most prevalent replicon types detected; tetA and tetB (32 and 26%, respectively) were the most prevalent antimicrobial resistance genes detected and iutA, was the most prevalent APEC virulence associated gene, detected in 50% of the isolates. Approximately 32% of the isolates examined could be classified as APEC-like, based on the presence of 3 or more genes of APEC virulence associated path panel (iroN, ompT, hlyF, iss, iutA). This study has identified a high prevalence of mcr-1 in poultry isolates in Brazil, suggesting that animal husbandry practices could result in a potential source of resistance to the human food chain in countries where application of colistin in animal health is practiced. Emergence of the mcr gene and associated colisitin resistance in production poultry warrants continued monitoring from the animal health and human health perspective.
RESUMO
Devido ao grande consumo de carne de frango a qualidade microbiológica da matriz também é crescente. As características físico-químicas da carne de frango a torna propícia ao crescimento de bactérias pertencentes à família Enterobacteriaceae e sua grande importância em saúde pública. O trabalho objetivou-se analisar a contagem de coliformes totais, isolamento e identificação de Salmonella spp. de 20 carcaças de frango obtidas pelo método de evisceração manual em abatedouro frigorífico registrado no Serviço de Inspeção Estadual do Rio De Janeiro localizado na região serrana. Das amostras analisadas, todas apresentaram contaminação por coliformes totais e quatro por Salmonella spp., evidenciando a necessidade de implantação de medidas de controle com os objetivos de assegurar melhores qualidades microbiológicas e a saúde do consumidor.
