Multidrug-resistant Klebsiella pneumoniae and Klebsiella oxytoca isolated from backyard broiler chickens and their contacts with antimicrobial resistance genes of Klebsiella pneumoniae

The objective of this study was to investigate the prevalence and phenotypic identification of antimicrobial resistance of K. pneumoniae and K. oxytoca recovered from backyard broiler chickens and their human contacts. The serotypes and genotypes of antibiotic resistance genes of K. pneumoniae isolates were investigated. A total of 80 samples were collected from backyard broiler chickens that showed signs of illness, sneezing, coughing, and diarrhea. Twenty stool samples were collected from individuals who had been in contact simultaneously. In total, 19 Klebsiella species were isolated, 12 of which were from broiler chicken samples and seven from human stool samples. Recovery rates of K. pneumoniae were 11.3% (n = 9/80) and 15% (n = 3/20) of broiler and human stool samples, respectively. K. oxytoca was detected in 3 of 80 (3.75%) broiler chicken and 4 of 20 (20%) human stool samples. Antimicrobial susceptibility showed that all 19 Klebsiella isolates were resistant to erythromycin and clindamycin (100%), followed by penicillin (94.7%) and ampicillin (84.3%). Within the 12 K. pneumoniae isolates, the most common serotype was K1. Antibiotic resistance gene profile of K. pneumoniae isolates was observed, with a high carrying rate of the macrolide gene ermB (91.7%), followed by the β-lactam genes bla_TEM (75%) and bla_CTX-M1 (66.7%). In conclusion, the emergence of multidrug-resistant (MDR) bacteria, K. pneumoniae and K. oxytoca in broiler backyard chickens and their human contacts is alarming, particularly for erythromycin and clindamycin. This underscores the need for alternatives like vaccination, probiotics, and better biosecurity to combat antimicrobial resistance.