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 <i>Klebsiella pneumoniae</i>, 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 <i>K. pneumoniae</i> from captive wild and migratory birds in Bangladesh along with their antimicrobial resistance characteristics. In this investigation, standard bacteriological methods were used to detect <i>K. pneumoniae</i> in 219 fecal samples. The positive isolates were confirmed by PCR and antibiotic susceptibility testing was performed by disk diffusion method. <i>K. pneumoniae</i> was detected in 93 (42.47%, 95% CI: 35.8-49.3) out of 219 fecal samples. The prevalence of <i>K. pneumoniae</i> 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 <i>bla</i>_TEM-1&2 encoding genes, with 45.2% and 15.1% carried <i>bla</i>_SHV-1 and <i>bla</i>_OXA-1,4&30, respectively. Additionally, resistance genes <b><i>strA</i></b> (30.1%), <b><i>tetA</i></b> (9.7%), and <b><i>sul1</i></b> (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 <i>K. pneumoniae</i> 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.