Association of diarrheagenic Escherichia coli with virotypes and sensitivity to antimicrobials in children of the Mexico City

Abstract

Diarrheal diseases continue to be a public health problem worldwide. Escherichia coli is one of the main etiological agents of diarrhea. The aim of the present work was to identify, through the polymerase chain reaction assay, the main virulence genes that characterize the different E. coli pathotypes that cause diarrhea in children under 5 years of age. A total of 151 stool samples from children with diarrhea were analyzed, of which 284 strains of E. coli were identified and DNA extracted. The virulence genes LT, STx1, STx2, EAST1, eaeA, bfpA, ial, aat, and astA were identified. Of the 284 strains analyzed, 179 (63.1%) were positive for at least one of the genes and 105 (36.9%) were negative for the nine genes studied. Of the 63%, enterotoxigenic E. coli was identified in a total of 63%, enterohemorrhagic E. coli in 25.0%, enteroaggregative E. coli in 25%, enteroinvasive E. coli in 20.7%, and enteropathogenic E. coli in 11.4%; These data are due to a strain of E. coli sharing genes with another strain. Children under 2 years old were the most affected. The adhesion phenotype, both aggregative and diffuse, was related to the presence of the aat and astA genes. The antibiogram showed that the strains of E. coli were resistant to more than three antibiotics, mainly ampicillin, cephalothin, amoxicillin/clavulanic acid, sulfamethoxazole-trimethoprim, and sensitive to amikacin, cefotaxime, and cefoxitin