Molecular Identification and Antimicrobial Resistance Characteristics of Extended-Spectrum Beta-Lactamase Producing Klebsiella pneumoniae Isolated from Captive Wild and Migratory Birds

The emergence and dissemination of antibiotic-resistant Klebsiella pneumoniae, particularly those are extended-spectrum beta-lactamase (ESBL) producers, thought to pose a serious threat to global health. This study aimed to isolate and identify the ESBL-producing K. pneumoniae from captive wild and migratory birds in Bangladesh along with their antimicrobial resistance characteristics. In this investigation, standard bacteriological methods were used to detect K. pneumoniae in 219 fecal samples. The positive isolates were confirmed by PCR and antibiotic susceptibility testing was performed by disk diffusion method. K. pneumoniae was detected in 93 (42.47%, 95% CI: 35.8–49.3) out of 219 fecal samples. The prevalence of K. pneumoniae was higher in captive wild birds (50%; 40/80) compared to migratory birds (38.1%; 53/139). The isolates showed high resistance to ampicillin (69.9%) and streptomycin (64.5%). Conversely, the highest sensitivity was recorded for trimethoprim-sulfamethoxazole (84.95%), followed by levofloxacin (79.57%) and gentamicin (69.89%). Molecular screening revealed that all positive isolates harbored bla_TEM-1&2 encoding genes, with 45.2% and 15.1% carried bla_SHV-1 and bla_OXA-1,4&30, respectively. Additionally, resistance genes strA (30.1%), tetA (9.7%), and sul1 (9.7%) were detected. The Multiple Antibiotic Resistance (MAR) index ranged from 0.18 to 0.64, with 63.4% of isolates classified as MDR. The isolation of MDR and ESBL producing K. pneumoniae from captive wild and migratory birds suggests that these birds may serve as reservoirs for the spread of these bacteria, potentially impacting public health in the study region.