Household wastewater as a sentinel for community-level antimicrobial resistance: a cross-sectional study in Gombe, Nigeria

Antimicrobial resistance (AMR) represents a critical global health challenge, with projections suggesting 10 million annual deaths by 2050. Environmental transmission routes, particularly through wastewater, remain understudied despite their significant role in resistance development and spread. This study investigated household wastewater as a sentinel for community-level AMR patterns in Gombe, Nigeria. A cross-sectional study was conducted between December 2024 and February 2025, collecting 320 household wastewater samples across seven districts in Gombe using multi-stage sampling techniques. Bacterial isolation followed standard conventional methods. Antibiotic susceptibility testing was performed using the disc diffusion method. Extended-spectrum beta-lactamase (ESBL) production was confirmed using double-disc synergy tests, and PCR detected key resistance genes in selected isolates. Microbiological analysis yielded 402 bacterial isolates, with 81% classified as multidrug-resistant (MDR). MDR prevalence across districts ranged from 60.3% to 95.9% (p < 0.01). Gram-negative bacteria predominated, with Escherichia coli (32.7%), Klebsiella pneumoniae (19.2%), and Pseudomonas aeruginosa (11.2%) being the most common. ESBL production was detected in 54% of tested isolates. MDR isolates demonstrated resistance to approximately 8 antibiotics (median), while non-MDR isolates showed resistance to only 1-2 antibiotics. Molecular analysis revealed a high prevalence of clinically significant resistance genes, with blaCTX-M detected in 100% of tested isolates. This study demonstrates household wastewater's value as a community-level antimicrobial resistance indicator. The high prevalence of MDR bacteria (81%) highlights significant environmental reservoirs that could contribute to community AMR transmission. Wastewater-based epidemiology can serve as a cost-effective complement to traditional clinical surveillance, especially in resource-limited settings.