Molecular studies on diarrhea-associated Escherichia coli isolated from humans and animals in Egypt

The molecular characteristics of Escherichia coli isolates from Egypt and the relationship of E. coli strains from claves, camels and humans are limited. We analyzed the genetic relationships of 48 diarrhea-associated E. coli strains isolated from sporadic diarrheal cases from humans (n = 26), calves (n = 14) and camels (n = 8) using multilocus sequence type (MLST), virulence genes, and pulsed field gel electrophoresis (PFGE). Enterotoxigenic E. coli (ETEC) accounted for 60.4% of all samples and the rest were Enteropathogenic E. coli (EPEC) 10.4%, Diffuse adhering E. coli (DAEC) 8.3%, Enteroaggreagative E. coli (EAEC) 6.3%, Verotoxigenic E. coli (VTEC) 6.3%, Untypable E. coli. 63% and Atypical enteropathogenic E. coli (aEPEC) 2.1%. We identified 17 new sequence types (ST) and 12 new alleles. Generally, strains divided into 6 clonal complexes, and clonal complex (CC) 10 was the major one, detected in (15/48; 31.3%) strains from humans, calves and camels. The close relationship among the strains from different hosts was regarding to mdh, purA, and recA genes which presented a minor variation in relation to other housekeeping genes. Conclusion: MLST analysis suggested an endemic prevalence of clonal complex (CC) 10 in Egypt. Same sequencing types (ST) could be detected in human, calf and camel, especially 5110, indicating the ability of E. coli to cross the host barrier. Together with PFGE results and virulence genotypes we conclude that human, calf and camel can be colonized and infected with similar E. coli strains and provide evidence of calves and camels role as a reservoir for similar strains of diarrhea-associated E. coli. (C) 2013 Elsevier B.V. All rights reserved.