The detection of multidrug-resistant (MDR) Aeromonas spp. in aquatic environments presents a growing public health concern. This study focused on the Adi Ganga River, a heavily urbanized and polluted tributary of the Ganga River in West Bengal, India. Surface water samples were collected from multiple locations along the Adi Ganga, and 33 distinct Aeromonas spp. were isolated. The study aimed to investigate the prevalence of MDR, extended-spectrum β-lactamase (ESBL), and plasmid-mediated AmpC-producing Aeromonas spp.
The isolates demonstrated high levels of resistance to β-lactam/β-lactamase inhibitor combinations (ampicillin/sulbactam: 94%, amoxicillin/clavulanic acid: 67%), carbapenems (imipenem: 91%), and cephalosporins (cephalexin: 61%, cefepime: 55%, ceftazidime: 47%, ceftriaxone: 39%). Resistance to tetracycline (18%) and chloramphenicol (15%) was comparatively lower.
ESBL production was confirmed in 56% of isolates, with blaTEM (94%), blaSHV (39%), and blaCTX-M group (27%) genes detected. Additionally, plasmid-mediated AmpC β-lactamase genes were found in 15% of isolates. The presence of MDR and ESBL-producing Aeromonas spp. in the Adi Ganga River underscores the environmental risk of antimicrobial resistance dissemination, posing serious implications for human, animal, and aquatic health.