Antibiotic Resistance Gene Profiling of Bacteria Isolated from Effluent Discharge Points of Abuja Pharmaceutical Manufacturing Plants

Pharmaceutical effluents are increasingly recognized as hotspots for antibiotic-resistant bacteria and resistance gene reservoirs in urban environments. This study profiled antibiotic resistance genes in bacteria isolated from effluent discharge points of three pharmaceutical manufacturing plants located in the Idu Industrial Area, Federal Capital Territory (FCT), Abuja. Effluent and receiving water samples were collected monthly over three months and processed for bacterial isolation on selective media. Minimum inhibitory concentrations were determined by broth microdilution. Multiplex PCR was employed to detect resistance genes including blaTEM, aac(6')-Ib, tetA, sul1, and integron-associated intI1 genes. A total of 116 bacterial isolates were obtained, predominantly Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. Resistance gene prevalence was high, with sul1 detected in 71% and blaTEM in 58% of multi-drug resistant isolates. Class 1 integrons, which facilitate horizontal gene transfer, were detected in 49% of isolates. The study demonstrates the role of pharmaceutical effluents in disseminating antimicrobial resistance determinants into the urban water environment of Abuja. Keywords: antibiotic resistance genes, pharmaceutical effluent, integrons, Abuja, multidrug resistance.