Microbiological quality, virulence attributes and antimicrobial resistance of ready-to-eat foods served at mass gatherings of Pakistan: a cross-sectional pilot surveillance study.

Abstract

This cross-sectional observational pilot study evaluated microbial quality, bacterial contaminants, their virulence determinants, and antimicrobial resistance profiles in RTE foods sold during MGs in Pakistan. A total of 74 RTE food samples were collected from 26 different festivals using convenience sampling approach. Based on Punjab Food Authority criteria (>10⁵ CFU/g), 63.5% (47/74) of samples were deemed unsatisfactory for consumption. Golgappa samples exhibited the highest polymicrobial contamination. Higher median microbial loads were found in outdoor (3.3 × 10³-1.7 × 10⁷CFU/g),single-day events with uncovered food and inadequate hygiene practices. Microbial loads differed significantly across MG categories (p = 0.015). Logistic regression revealed that RTE collected from religious (OR = 7.81, 95% CI: 1.39-56.87) and social gatherings (OR = 8.29, 95% CI: 1.51-57.78) had significantly higher odds of exceeding microbial safety limits. Enterobacter spp. (48.6%; 36/74) was predominantly isolated, while Shigella spp. (6.7%; 5/74) was least prevalent. Enterobacter spp. showed significant association with cooked pulses (p = 0.0132), whereas cooked rice samples showed fourfold higher odds of Staphylococcus spp. detection compared to other food categories (p = 0.012, OR = 4.05, 95%CI = 1.3-12.5). Network analysis identified Enterobacter spp. as dominant hub contaminant, exhibiting strong tendency to form biofilms (p = 0.0006) with significantly increased likelihood of gentamicin (OR = 3.9) and ciprofloxacin (OR = 1.6) resistance. Overall, 78.9% (15/19) of Staphylococcus spp., 66.6% (10/15) of E. coli, and 5.5% (2/36) of Enterobacter spp. showed virulence potential.