Beta-lactam resistance in Escherichia coli isolated from meat and feces from feedl...
| Grant number: | 18/02691-4 |
| Support type: | Regular Research Grants |
| Duration: | September 01, 2018 - November 30, 2020 |
| Field of knowledge: | Biological Sciences - Microbiology - Applied Microbiology |
| Principal Investigator: | Tiago Casella |
| Grantee: | Tiago Casella |
| Home Institution: | Faculdade de Medicina de São José do Rio Preto (FAMERP). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São José do Rio Preto , SP, Brazil |
| Assoc. researchers: | Juliana Regina Peiró ; Luiz Claudio Nogueira Mendes ; Mara Corrêa Lelles Nogueira |
| Associated scholarship(s): | 19/16003-5 - Identification of mobilizing determinants of third-generation cephalosporin resistance genes in Escherichia coli,
BP.TT 18/16147-4 - Beta-lactam resistance in Escherichia coli isolated from meat and feces from feedlot lambs, BP.TT |
Abstract
The beta-lactam resistance is an important concern for public health since these are one of the most used drugs to treat human infections. Several studies report the transmission of bacteria and resistance genes from food to humans via handling or consumption. Research in antimicrobial resistant bacteria from feedlot-lambs is a neglected field in Brazil, since this herd does not have significance in economics. However, the internal consumption of lamb meat has increased in the country, considered a great producer, exporter and consumer of meat in the world. Thus, it is mandatory to provide knowledge about beta-lactam resistant bacteria isolated from the meat production chain. For this feedlot-lambs' feces and retail lamb meat samples will be collected and processed in order to compare the resistance determinants. Escherichia coli isolates will be selected in MacConkey agar supplemented with 4 mg/L of ceftiofur, submitted to antimicrobial susceptibility test and molecular characterization of genes and plasmids responsible for beta-lactam resistance. The isolates will be also compared according to phylogenetic groups, PFGE and MLST. We have been recovered 136 E coli isolates from 105 lambs in two previous years, as being 87 from 2016 and 49 from 2017. Among the characterized isolates from 2016, blaCTX-M variants (including blaCTX-M-14, still scarce in Brazil) and blaCMY-2 were identified as responsible for cephalosporin resistance, with predominance of the second. Molecular typing by ERIC-PCR did not reveal predominance of a specific isolate, although some recovered from different animals are very similar, which leads us to believe in the essential role of plasmids in dissemination of blaCMY-2. Among the characterized isolates from 2017, there is an evident predominance of blaCTX-M-1-like genes, besides other blaCTX-M variants and blaCMY-2, and the ERIC-PCR-typing did also not indicate predominance of a specific strain, once more showing an important role of plasmid in the dissemination of resistance genes. Moreover, in 2017 it was possible to collect samples from lambs' carcass, from which 4 E. coli isolates resistant to ceftiofur were recovered. Among these 4 isolates, 1 is clonally related to 2 other isolates recovered from feces of 2 different lambs by XbaI-PFGE typing. This result demonstrates the sharing of bacterial strains from the gastrointestinal tract of feedlot animals and the durability of them after the animals' slaughter. The evidences obtained until now point out the plausibility of tracing the spread of antimicrobial resistance genes in the meat production chain, the main objective of this scientific project. (AU)