Antimicrobial Resistance, Integron and Class 1 Integron in E. coli isolated from Ready-to-Eat Foods

A total of 740 ready-to-eat food samples were collected from roadside shops in Tiruchirappalli, Tamil Nadu, to assess E. coli contamination. Among these, 500 (68%) samples tested positive for E. coli, while 240 were negative. Biochemical characterization confirmed 162 (32.4%) isolates. Simultaneously, water samples from these shops were analysed, revealing E. coli contamination in 295 samples, with bacterial counts ranging from 8.4×10⁵ to 9.5×10⁸ CFU/ml. Molecular detection confirmed the uidA gene in 139 (85.8%) isolates. Antibiotic susceptibility testing of 139 strains revealed 96 (69.1%) as drug-resistant, with 16.7% showing 100% resistance. Multidrug-resistant isolates exhibited 75.9% resistance to streptomycin. Integron integrase was detected in 57 (59.37%) isolates, with 56 (98.2%) carrying the intI1 gene. Contamination was linked to water and human handling (p≤0.01). Implementing hygiene practices among food handlers is crucial to mitigating the risk of E. coli contamination.