Abstract

Rapid urbanization in Asaba, Delta State, has increased municipal solid waste generation, leading to extensive open dumping. Dumpsites harbor diverse microbial communities, including pathogenic and antibiotic-resistant organisms, posing environmental and public health risks. This study assessed the microbial composition, diversity, and antimicrobial resistance of bacteria and fungi in market-related dumpsites in Asaba, providing baseline data to inform waste management and public health strategies. Soil, decomposed waste, and leachate samples were collected from seven market dumpsites. Determination of microbial loads and identification of bacteria and fungi were by standard microbiological techniques. Antibiotic susceptibility of bacterial isolates was evaluated using the Kirby–Bauer disk diffusion method. Bacterial loads exceeded fungal counts in all sample types, with leachates exhibiting the highest densities. Dominant bacteria included Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Salmonella typhi. Fungal isolates were mainly Aspergillus, Penicillium, Mucor, Rhizopus, and Candida albicans. Enteric bacteria were concentrated in leachates, confirming fecal contamination. Antibiotic resistance was prevalent, with MAR indices ranging from 0.2 to 0.82; highest resistance occurred against ampicillin, tetracycline, and erythromycin. Dumpsites in Asaba serve as reservoirs for pathogenic and multidrug-resistant microorganisms. Leachates facilitate microbial spread, amplifying environmental and health risks. Effective waste management, routine microbial monitoring, and antimicrobial resistance surveillance are urgently needed to safeguard public health.