Isolation and Identification of Enterohaemorrhagic Escherichia coli O157:H7 from Beef and Lambs Meat in Tree Marked (Diguel, Dembe and Gougi) in Ndjamena City-Chad

Abstract: The Enterohaemorrhagic Escherichia coli O157:H7 is emerging and major zoonotic foodborne pathogen. It has and increasing concerning about spread of antimicrobial- resistant strain. This study aimed to isolate and characterize Shiga toxin producing Enterohaemorrhagic Escherichia coli O157:H7 from row beef and lamb meats and determine their and microbial susceptibility pattern from December 2025 to January 2026, and total of 306 beef and lamb meat samples were collected from different Market in Ndjamena city- Chad. The collected sample were analyzed microbiologically for the presence of Enterohaemorrhagic Escherichia coli O157:H7 and Shiga toxin producing E.coli and determination of their antimicrobial susceptibility pattern following the standard bacteriological and total of 306 167 ( 54.57% ) were biologically positive for E.coli and 100 ( 33.66% ) were positive of Shiga toxin E.coli O157:H7. Respectively E.coli isolates showed the highest level of susceptibility to the tetracycline, Ciprofloxacin and cefepime (100%), but the highest level of resistance to Ampicillin and Amoxicillin (100%) and intermediate susceptibility to Gentamicin, ofloxacin, ceftriaxone of the tested isolate, 0(0%) of E.coli showed multidrug resistant. This study revealed the occurrence of Shiga- toxin producing E.coli O157:H7 in beef and lambs meat. In conclusion, a nationwide phenotypic characterization, in depth-typing, and drug- resistant identification of E.coli O157:H7.