Prevalence and Antimicrobial Resistance Profiles of Salmonella Isolated From Table Eggs in Rupandehi, Nepal

Non-typhoidal Salmonella (NTS) is a leading cause of foodborne illness globally, with poultry eggs serving as a primary vehicle for human infection. The emergence of antimicrobial resistance (AMR) in Salmonella, particularly to critically important antibiotics, compounds this public health threat.

This cross-sectional study, conducted in the Rupandehi district of Nepal, aimed to assess Salmonella prevalence in table eggs and characterize the AMR profiles of recovered isolates.

A total of 150 eggs were collected from layer farms (n = 45), retail shops (n = 60) and restaurants (n = 45). Salmonella was isolated using standard culture-based methods, and antimicrobial susceptibility was determined via the Kirby-Bauer disk diffusion method.

The overall prevalence of Salmonella was 10.0% (95% CI: 5.6%-16.2%). A statistically significant contamination gradient was observed across the supply chain, with prevalence increasing from 2.2% at farms to 15.0% at retail shops and 11.1% at restaurants (Fisher's exact test, p < 0.05). Logistic regression analysis identified retail shops as a significant risk factor for contamination compared to farms (OR = 7.6). Antimicrobial susceptibility testing of 17 isolates revealed alarmingly high resistance rates to ciprofloxacin (88.2%), tetracycline (76.5%) and ampicillin (70.6%). Furthermore, 58.8% of isolates were multidrug-resistant (MDR).

These findings reveal systemic failures in post-farmgate hygiene and underscore the urgent need for integrated One Health interventions, including enhanced surveillance, improved food handling practices and stringent antimicrobial stewardship in the poultry sector to mitigate this pressing public health risk.