Detection and Antimicrobial Susceptibility Patterns of Bacterial Isolates from Poultry Farm Environments Using Microbact™ ID 24E

The extensive prophylactic and therapeutic administration of antibiotics within commercial poultry operations has heightened international public health concerns regarding the diversification and environmental dissemination of antimicrobial-resistant bacterial populations. This investigation evaluated the phenotypic, morphological, and biochemical profiles and antimicrobial susceptibility spectra of bacterial isolates recovered from poultry farm environments in Kwara State, Nigeria. Approximately 25 poultry dropping samples were collected aseptically across three commercial production facilities and processed using selective media (MacConkey agar and Eosin Methylene Blue agar) following standard microbiological dilution techniques. Nine representative Gram-negative bacterial isolates were selected on the basis of distinct colonial morphology and characterised using conventional biochemical protocols in conjunction with the miniaturised Microbact™ ID 24E identification system. The identified isolates comprised Pantoea agglomerans, Enterobacter asburiae, Pseudomonas fluorescens, Pasteurella multocida, Aeromonas hydrophila, Brevundimonas diminuta, Vibrio parahaemolyticus, Burkholderia cepacia, and Klebsiella pneumoniae. Comprehensive biochemical fingerprinting revealed pronounced metabolic divergence in enzymatic expression and carbohydrate fermentation profiles. Antimicrobial susceptibility testing using the Kirby–Bauer disk diffusion method in accordance with Clinical and Laboratory Standards Institute (CLSI M100) criteria demonstrated complete (100.0%) resistance to all evaluated β-lactam antibiotics (ceftazidime, cefuroxime, and amoxicillin–clavulanate). By contrast, high to moderate susceptibility was exhibited towards gentamicin (55.6% susceptible, 22.2% resistant) and ofloxacin (44.4% susceptible, 11 . 1% resistant), whereas nitrofurantoin exhibited intermediate to resistant activity across 88.9% of the isolates. These findings demonstrate that poultry housing environments represent formidable environmental reservoirs of multidrug-resistant opportunistic enterobacteria and environmental saprophytes, underscoring the urgent imperative for strict veterinary antimicrobial stewardship and standardised phenotypic surveillance in resource-constrained settings