Sharmistha Goswami

Considering the ecological diversity of E. coli, the main aim of this study was to determine the prevalence, phylogroup diversity, and antimicrobial susceptibility of E. coli isolated from 383 different clinical and environmental sources. In total, varied prevalence was observed of the 197 confirmed E. coli that were isolated (human–100%, animal–67.5%, prawn–49.23%, soil–30.58%, and water–27.88%). Of these isolates, 70 (36%) were multidrug-resistant (MDR). MDR E. coli was significantly associated with their sources (χ² = 29.853, p = 0.001). Humans (51.67%) and animals (51.85%) carried more MDR E. coli than other environments. The eae gene indicative of recent fecal contamination was not detected in any isolate, indicating that these E. coli isolates could be present in these environments for a long time and became naturalized. Phylogroup B1 (48.22%) was the predominant group, being present in all hosts analyzed and with the commensal E. coli group A (26.9%) representing the second predominant group. According to chi-square analysis, phylogroup B1 was significantly associated with E. coli from humans (p = 0.024), soil (p < 0.001) and prawn samples (p < 0.001). Human samples were significantly associated with phylogroup B1 (p = 0.024), D (p < 0.001), and F (p = 0.016) of E. coli strains, whereas phylogroup A (p < 0.001), C (p < 0.001), and E (p = 0.015) were associated with animal samples. Correspondence analysis results also indicated the association of these phylogroups with their hosts/sources. The findings of this study exhibited a non-random distribution of phylogenetic groups, though the diversity index was highest for human E. coli phylogroups.

The burden of street food contamination remains significantly higher among developing countries, making its consumers' health compromised. This study aimed at identifying Escherichia coli in local street foods, track their sources and characterize their virulence properties, antimicrobial susceptibility patterns, and incidence of recent fecal contamination. Twelve E. coli isolates isolated from 28 types of street foods sold at different locations of Dhaka metropolitan city were confirmed by both culture-based and molecular methods. Phylogroup B1 of environment origin was the most predominant (58%, n=12) among the isolates, followed by commensal phylogroup A (16%), phylogroup C (8%), D (8%), and E (8%). Alarmingly, 8% of the isolates were confirmed to be Enteropathogenic E. coli (EPEC), harboring hlyA gene, and 41% were due to recent fecal contamination cases confirmed by the presence of the eae gene. Isolates showed the highest resistance to ampicillin, followed by chloramphenicol. However, resistance could not be correlated to the presence of class 1 integron as isolates sensitive to these antibiotics also harbored this mobile genetic element. The findings of this study demonstrated the presence of antibiotic-resistant, potentially pathogenic E. coli in street food which emphasizes the health hazard associated with consumption of such foods.

The burden of street food contamination remains significantly higher among developing countries, making its consumers’ health compromised. This study aimed at identifying Escherichia coli in local street foods, track their sources and characterize their virulence properties, antimicrobial susceptibility patterns, and incidence of recent fecal contamination. Twelve E. coli isolates isolated from 28 types of street foods sold at different locations of Dhaka metropolitan city were confirmed by both culture-based and molecular methods. Phylogroup B1 of environment origin was the most predominant (58%, n=12) among the isolates, followed by commensal phylogroup A (16%), phylogroup C (8%), D (8%), and E (8%). Alarmingly, 8% of the isolates were confirmed to be Enteropathogenic E. coli (EPEC), harboring hly A gene, and 41% were due to recent fecal contamination cases confirmed by the presence of the eae gene. Isolates showed the highest resistance to ampicillin, followed by chloramphenicol. However, resistance could not be correlated to the presence of class 1 integron as isolates sensitive to these antibiotics also harbored this mobile genetic element. The findings of this study demonstrated the presence of antibiotic-resistant, potentially pathogenic E. coli in street food which emphasizes the health hazard associated with consumption of such foods.