Detección de grupo filogénetico y susceptibilidad antimicrobiana de E. coli aislada de leche cruda proveniente de Zamora y Loja

Abstract

Abstract:Escherichia coli, is a gram negative bacillus that is part of the intestinal microbiota of man and animals; Most of them are harmless, but certain strains have the capacity to cause gastrointestinal infections, mainly affecting children, the elderly and immunocompromised people. The objective of the present work was to determine the phylogenetic group and the antimicrobial susceptibility of E. coli strains isolated from raw milk. Using the multiple-PCR technique, 39 strains were analyzed and the four phylogenetic groups A, B1, B2 and D were identified with 15.38%, 7.69%, 66.67% and 10.26% respectively; determining in our study that the source of contamination in raw milk is the E. coli strains from human fecal matter and to a lesser extent from excretion from animals. In relation to antimicrobial susceptibility to 14 antibiotics using the Muller-Hinton agar diffusion method, resistance percentages of less than 10% were evident for tetracycline, streptomycin, ampicillin, and cephalotin; as well as percentages of sensitivity of 100% towards ceftazidime, cefepime and imipenem, therefore no ESBL producing strains were found.