Atypical enteropathogenic Escherichia coli associated with an acute diarrhoeal disease outbreak due to fermented soybean in Keifang, Mizoram, India: a challenge toward food safety and prevention efforts

Introduction Foodborne and waterborne gastrointestinal disease outbreaks are frequently reported from the northeastern region of India. Methods In the present study, an outbreak of acute gastroenteritis in Keifang village of Mizoram, India, was investigated following official notification through the state Integrated Disease Surveillance Program (IDSP) unit. Results The investigation involved descriptive epidemiology and exposure assessment for 40 affected individuals. Stool samples from all affected patients, healthy control individuals ( n = 20), and leftover food specimens ( n = 2) were collected for laboratory analysis. All samples were processed using standard microbiological methods, conventional PCR, and real-time PCR assay for the identification of causative agents. Pure bacterial cultures underwent antimicrobial sensitivity testing. Data were analyzed to determine the attack rate, construct the epicurve, and perform spot mapping of the outbreak. Atypical enteropatho genic Escherichia coli (aEPEC) was isolated from all 40 affected individuals and one food specimen. No other significant microbial pathogens, including bacteria, viruses, or parasites, could be detected in the specimens by any method. Discussion All the aEPEC isolates were sensitive to most antimicrobials, except ampicillin and ceftazidime. Since all the infected patients consumed the same fermented soybean purchased from a single vendor, and aEPEC was isolated from both the patients and the fermented soybean, this suggests a strong correlation between the aEPEC isolates and the outbreak in Keifang, Mizoram, India, which was transmitted through fermented soybean.