Antimicrobial Resistance Profiling of Fecal Indicator Bacteria from Poultry in Informal Markets in Maputo, Mozambique

Abstract

Background: Informal, open-air markets, an important source of food and livelihood for people in low and middle-income countries, present risks for emerging respiratory and enteric infections. This analysis reports on the baseline findings, prior to implementation of a poultry market-level intervention conducted through the ChEEP ChEEP 2 (Chicken Exposures and Enteric Pathogens in Children Exposed through Environmental Pathways) Study. The study uses mixed methods to evaluate the impact of market improvements on hygiene practices, antimicrobial resistance (AMR), and occupational exposure risks in informal markets in Maputo, Mozambique. Methods: We collected 90 whole raw chicken carcass samples (30 per market) from three informal markets representing different infrastructure and hygiene conditions (Recently Upgraded, Intervention, and Unimproved) between July 21, 2025, and August 12, 2025, in Maputo, Mozambique. Escherichia coli isolates (n=90, 1 per chicken carcass) were cultured and tested for susceptibility to six antibiotics: Trimethoprim-sulfamethoxazole, Ciprofloxacin, Cefepime, Ceftriaxone, Gentamicin, and Tetracycline using Kirby-Bauer disk diffusion susceptibility testing. Market-level differences in AMR outcomes were assessed using Fisher’s exact tests. Hygiene practices were observed using a structured checklist and summarized into slaughtering and processing hygiene indices. Logistic regression models were used to assess whether slaughtering and processing hygiene indices were associated with resistance to individual antibiotics and with multidrug resistance (MDR). MDR was defined at different thresholds and represents the number of antibiotics to which an isolate was resistant. Results: Across E. coli isolates (n=90), resistance to several antibiotics was high, particularly tetracycline (96.67%) and ciprofloxacin (95.56%), while resistance to cefepime (2.22%) and ceftriaxone (12.22%) was low. Gentamicin resistance among E. coli isolates differed significantly (p= 0.00495), ranging from 76.67% in the Recently Upgraded market to 100% resistance in the Intervention market. After Holm correction, only the Intervention vs. Recently Upgraded market comparison remained significant (p=0.047). However, resistance to the other five antibiotics showed no statistically significant differences in resistance between markets. Hygiene practices were consistently poor across all three markets (30 vendors per market). Personal protective equipment use was minimal (0-3.3% gloves; 10-70% aprons 0-20% facemasks). Handwashing was largely absent at key contamination points (3.3% before slaughtering; 0-3.3% after scalding/before defeathering; 0-6.7% before evisceration; and 0-3.3% before carcass rinsing. Surface sanitation remained limited (3.3-36.7% of vendors per market), and proper waste disposal was infrequent (0-6.7%). Logistic regression models showed no associations between slaughtering or processing hygiene indices and resistance to individual antibiotics or MDR. Conclusion: We found that poultry sold in Maputo’s informal markets carried a high burden of AMR, and vendor hygiene practices were consistently poor. Although summary hygiene indices were not associated with AMR, observed conditions indicate poor hygiene practices during slaughtering and processing. These baseline results establish the foundation for pre/post comparisons, following the ChEEP ChEEP 2 intervention, to evaluate changes in hygiene behavior, pathogen exposure risks, and AMR patterns.