Comprehensive Genomic and Pathophysiological Characterization of Diarrheagenic Escherichia coli in a Mouse Model

All three enterotoxigenic E coli were isolated and characterized clinical in the laboratory of Dr. Asish K. Mukhopadhyay and Dr. Goutam Chowdhary's at the ICMR - National Institute for Research in Bacterial Infections, Kolkata, India. Sequencing was carried out in the laboratory of Dr. Yogendra S. Padwad, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India while sequence analysis was performed in the laboratory of Dr. Ravi Shankar at CSIR-Institute of Himalayan Bioresource Technology, Palampur, India. Enterotoxigenic Escherichia coli (ETEC) is a clinically significant diarrheagenic pathotype of E. coli and a major etiological agent of acute secretory diarrhea worldwide. It is a leading cause of travellers diarrhea and pediatric diarrheal illness, particularly in regions with inadequate sanitation and limited access to safe drinking water. Transmission occurs predominantly via the fecal oral route through consumption of contaminated food or water. Following ingestion, ETEC colonizes the small intestine by means of specific colonization factors (CFs) that facilitate adherence to the intestinal epithelium. The pathogenicity of ETEC is primarily mediated by the production of heat labile (LT) and or heat stable (ST) enterotoxins. These toxins activate intracellular signaling pathways, including adenylate cyclase and guanylate cyclase, leading to dysregulation of electrolyte transport, enhanced chloride secretion, and inhibition of sodium absorption. Consequently, excessive fluid secretion into the intestinal lumen results in profuse watery diarrhea without significant intestinal inflammation. Clinically, ETEC infection is characterized by watery stools, abdominal cramps, nausea, and vomiting, with fever and blood in stool typically absent. Severe or prolonged infection may cause dehydration, posing a substantial risk to infants and young children. Preventive measures emphasize improvements in water quality, food safety, and hygiene practices, while treatment primarily involves oral rehydration therapy, with antimicrobial agents considered only in moderate to severe cases.