Enterotoxigenic Escherichia coli (ETEC) are major causes of childhood diarrhea in low and middle income countries including Colombia, South America. To understand the diversity of ETEC strains in the region, clinical isolates obtained from northern Colombia children were evaluated for multiple locus sequencing typing, serotyping, classical and nonclassical virulence genes, and antibiotic susceptibility. Among 40 ETEC clinical isolates evaluated, 21 (52.5%) were positive for LT gene, 13 (32.5%) for ST gene, and 6 (15%) for both ST and LT. The most prevalent colonization surface antigens (CS) were CS21 and CFA/I identified in 21 (50%) and 13 (32.5%) isolates, respectively. The eatA, irp2, and fyuA were the most common nonclassical virulence genes present in more than 60% of the isolates. Ampicillin resistance (80% of the strains) was the most frequent phenotype among ETEC strains followed by trimethoprim-sulfamethoxazole resistance (52.5%). Based on multiple locus sequencing typing (MLST), we recognize that 6 clonal groups of ETEC clinical isolates circulate in Colombia. ETEC clinical isolates from children in northern Colombia are highly diverse, yet some isolates circulating in the community belong to well-defined clonal groups that share a unique set of virulence factors, serotypes, and MLST sequence types.

Introduction: Intestinal Escherichia coli pathogens are major causes of diarrhoeal disease in children under five years of age worldwide. The aim of this study is to evaluate the association of E. coli pathotypes with childhood diarrhoea in Colombia. Methodology: A case-control study was conducted in 815 samples from children younger than five years of age in Cartagena, Colombia (466 cases and 349 controls). Controls were randomly selected 1:1 to cases, to obtain 349 cases and 349 controls. Results: This study revealed that 27 (7.44%) cases and 12 (3.43%) controls were positives for any of the E. coli pathotypes. The difference observed was statistically significant indicating that E. coli pathotypes were associated with cases of childhood diarrhoea. Enterotoxigenic E. coli (ETEC) was the most common pathotype associated with childhood diarrhoea. Additional E. coli pathotypes were also identified. Conclusions: We conclude that after the adjustment by age, sex and socioeconomic stratum, the odds ratio obtained by logistic regression shows an association between infection with ETEC and childhood diarrhoea.

This prospective acute gastroenteritis (AGE) surveillance was conducted in the inpatient and emergency room settings at a referral pediatric hospital to determine the prevalence of diarrheagenic Escherichia coli (DEC) in children<12 years of age with AGE in Davidson County, Tennessee. Subjects 15 days to 11 years of age, who presented with diarrhea and/or vomiting, were enrolled. Stool specimens were processed for detection of DEC using multiplex polymerase chain reaction. From December 1, 2011, to June 30, 2012, a total of 79 (38%) out of 206 stool specimens from children with AGE tested positive for E. coli. A total of 12 (5.8%) out of 206 stool specimens from children with AGE were positive for a DEC. Eight (67%) out of these 12 were positive for enteropathogenic E. coli, and the remaining 4 were positive for enteroaggregative E. coli. DEC clinical isolates clustered with known E. coli enteropathogens according to multilocus sequencing typing.