Circulation of enterotoxigenic Escherichia coli (ETEC) isolates expressing CS23 from the environment to clinical settings

Abstract

Enterotoxigenic Escherichia coli (ETEC) is one of the leading causes of infant diarrhea in low- and middle-income countries (LMICs). Diarrheal pathogens are transmitted through environmental reservoirs; however, the bacterial clones that spread across the human-environment interphases remind unexplored. We aimed to determine the relationship and clonal dissemination of ETEC between children with diarrhea (> 5 years of age) and polluted water samples from local river in La Paz, Bolivia. Our study used whole genome sequencing and phenotypic fingerprinting system (PhenePlates) to analyze ETEC strains. We showed that ST218 and ST410 LT+STh CS23 ETEC were found with high frequency in both samples. The CS23 ETEC isolates were found within several STs, E. coli phylogroups A, B1, C, and D, and across ETEC lineages. Our comparative genomic analysis and PhenePlate screening of globally distributed clinical ETEC strains suggested that virulent CS23 plasmids acquisition occurs independently of the bacterial chromosomal background. Environmental strains were more often multidrug-resistant (MDR) than clinical isolates and harbored the class 1 integron-integrase gene intI1 next to the MDR cassettes. Retrospective analysis of antibiotic resistance in ETEC revealed a high frequency of MDR in clinical isolates. The LT+STh CS23 ETEC isolates showed an increased biofilm ability at environmental temperature, equal cytotoxicity, and significantly lower adherence to human epithelial cells compared to ETEC expressing other CFs. Together, our findings suggest that CS23 is more prevalent in ETEC than previously estimated, and the Choqueyapu River is a reservoir for LT+STh CS23 ETEC containing strains capable of causing diarrheal cases in children.

Metallo-Glycodendrimeric Materials against Enterotoxigenic Escherichia coli

“…Fecal contamination is the main vehicle for zoonotic pathogens [5][6][7][8]. Several pathogenic bacteria, including ETEC, found in livestock can contaminate water, soil and farm environments and cause disease in humans and pets [9,10]. ETEC are characterized by the ability to produce two types of virulent factors: adhesins promoting binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion [11].…”