Comparative study between diarrheagenic Escherichia coli virotypes from Mexico City and San Luis Potosí

Abstract

The distribution and frequency of Escherichia coli virotypes can vary considerably from region to region, due to the geographical characteristics, the degree of social lag as well as the population of each region. Therefore, the objective of the present work was to compare Escherichia coli isolated from children with diarrhea obtained from two states with different levels of social lag and establish virotypes, adhesion to HEp-2 cells, biofilm formation, and antimicrobial resistance of this bacterium. In the present work, we compared E. coli isolated from children with diarrhea obtained from the City of San Luis Potosí (S.L.P.) with E. coli isolated from children with diarrhea of Mexico (City CDMX), with the purpose of identifying and establishing vi-rotypes, adherence to HEp-2 cells, formation of biofilms, and antimicrobial resistance of these bacteria. The results showed that the percentage of virotypes found in S.L.P., were higher with respect to the virotypes found in the CDMX, being entero-toxigenic the most frequent virotype for both populations. The incidence of this virotype was higher for E. coli isolated from S.L.P., and the statistical analysis showed p < 0.000. The incidence of the enteroinvasive and EHEC virotypes was higher in the state of S.L.P., with p < 0.000. The adhesion phenotype, both aggregative and diffuse, was related to the presence of the aat and astA genes. The tests to determine the production of biofilms in strains of E. coli, allowed us to determine that the method in Congo red agar, were the most effective for its evaluation. In relation to the antimicrobials tested, a higher percentage of resistance of the E. coli strains of the CDMX was observed, in relation to the strains of S.L.P., with a statistically significant difference of p < 0.05.