Caracterização fenotípica e genotípica de Escherichia coli isoladas de suínos abatidos no estado de Pernambuco, Brasil

Abstract

Aimed with the present study to analyze phylogenetically, detect the presence of virulence genes and plasmids, determine the antimicrobial susceptibility profile, and verify biofilm production in Escherichia coli strains isolated from healthy pigs slaughtered in Pernambuco state, Brazil. Bacteria isolated from intestinal content were subjected to biochemical tests. 126 strains were confirmed as Escherichia coli, which were subsequently analyzed by genotypic and phenotypic methods like polymerase chain reaction (PCR), electrophoresis, disk diffusion, and adhesion microplates test. The most common phylogenetic group was B1 with 88.10% (111/126) of the strains, followed by 4.76% in group D (6/126), 3.97% (5/126) in group B2, and 3.17% (4/126) in group A. 987P (F6) gene was the most common, found in 96.72 % (118/122) of strains that showed some virulence gene, and followed by BFP in 90.98% (111/122), K88 (F4) in 18.85% (23/122), and STb in 2.46% (3/122). LT, STa, STX2e, K99 (F5), and F18 genes were not detected in any of the strains. 46.03% (58/126) of the tested strains had plasmidial content, and in resistance evaluation test to antimicrobial drugs, all isolates were resistant to erythromycin and lincomycin, while chloramphenicol was the most efficient antibacterial drug in vitro. Multiple resistance index ranged from 0.2 to 0.9, determining multidrug resistance in 99.21% (125/126) of the strains. The ability to produce biofilm was detected in 46.03% (58/126) of the strains. This study was the first of its kind in Pernambuco state. Although the strains analyzed in this study come from healthy animals and most of them have been considered commensal, the presence of virulence genes, as well as high levels of multiple antimicrobial resistance warn about the risks of transmission of bacteria with this profile between livestock and human populations, reinforcing the need for more studies that encourage the adoption of appropriate health managements in herds and presenting alternatives to control these micro-organisms.