Abstract
<title>Abstract</title> <p>Background Chicken eggs are an important source of high-quality protein but may serve as vehicles for antibiotic-resistant enterobacteria and antibiotic residues, posing a potential public health risk. Data on the occurrence of these hazards in eggs from Bangladesh remain limited. Objectives This study aimed to isolate and identify Escherichia coli and Salmonella spp. from chicken eggs, determine their antimicrobial susceptibility profiles, and detect antibiotic residues in egg samples. Methods A total of 63 chicken eggs (21 brown-shell, 21 white-shell, and 21 indigenous eggs) were collected from three upazilas of Bogura district, Bangladesh. Isolation and identification of bacteria were performed using standard cultural, staining, and biochemical methods. Antimicrobial susceptibility was assessed by the Kirby–Bauer disc diffusion method. Antibiotic residues were screened in 14 additional egg samples using thin-layer chromatography (TLC). Results E. coli was detected in 36.50% (23/63) of eggs, comprising 23.80% shell contamination and 12.69% egg-content contamination. Salmonella spp. were isolated from 22.22% (14/63) of eggs, including 19.04% shell and 3.17% content contamination. Indigenous eggs showed higher bacterial prevalence than commercial layer eggs. Both bacterial species exhibited complete resistance to penicillin and high resistance to ampicillin, amoxicillin, tetracycline, and ciprofloxacin, while maintaining high susceptibility to ceftriaxone and gentamicin. Antibiotic residues were detected in 2 of 14 (14.28%) samples, with one positive for oxytetracycline and one for ciprofloxacin. Conclusion Chicken eggs marketed in the study area may act as reservoirs of multidrug-resistant enterobacteria and occasionally contain antibiotic residues. Strengthening farm hygiene, antimicrobial stewardship, and compliance with withdrawal periods is essential to improve egg safety and protect public health.</p>