Prevalence and Antibiotic Resistance Profiles of Enterobacteria in Cynopterus sphinx (Fruit Bats) in Chattogram, Bangladesh

Abstract

Antimicrobial resistance (AMR) in wildlife is an emerging global health challenge that connects environmental interactions with the spread of antibiotic-resistant bacteria, with potential impacts on biodiversity. This study evaluates the presence of antimicrobial-resistant enterobacteria in Cynopterus sphinx and assesses their role in wildlife-human interaction dynamics. Bats, as potential reservoirs of resistance, were sampled through rectal swabs, yielding bacterial cultures that formed distinct colonies on different agar with their specific characters. The bacterial identification was confirmed using biochemical tests, including Indole and MR tests. To assess antibiotic resistance, the disk-diffusion method was employed on Mueller-Hinton agar, with antibiotics selected according to the CLSI, 2017 guidelines. The study also analyzed the morphometric data of Cynopterus sphinx that depicted female bats were generally more prominent than males regarding body weight, but other measurements showed no significant sex-based differences. The antibiogram of Salmonella spp. and Enterobacter spp. isolated from rectal swabs revealed alarming resistance patterns. Salmonella spp. demonstrated 100% resistance to Amoxicillin, Erythromycin, Sulfamethoxazole, and Amoxicillin/Clavulanic acid, while also showing high resistance (92-93%) to Colistin and Ceftazidime. However, Salmonella isolates exhibited complete susceptibility to Gentamicin, Tetracycline, Nalidixic acid, and Chloramphenicol. Enterobacter spp. exhibited resistance to several antibiotics, including Amoxicillin, Colistin, Ceftazidime, Erythromycin, Streptomycin, and Sulfamethoxazole, but showed 100% susceptibility to Cefotaxime, Ciprofloxacin, Nalidixic acid, Amikacin, Gentamicin, Tetracycline, Ceftriaxone, Chloramphenicol, Cotrimoxazole, and Sulfamethoxazole. These findings highlight the critical issue of AMR in wildlife, particularly bats, suggesting that they may play a significant role in the transmission of antibiotic-resistant pathogens. The results emphasize the importance of monitoring antimicrobial use in both human and veterinary medicine to mitigate the spread of resistance.