Abstract: [Objective] To investigate the infection of Klebsiella oxytoca in the swabs of pigs from a large-scale pig farm in Kuqa City, and to study its biological characteristics. [Methods] 80 nasal swab samples with respiratory tract infection symptoms were collected from the pig farm, and the bacterial species were identified by bacterial isolation and 16S rDNA sequencing. The drug resistance of the isolated strains was understood by detecting the drug sensitivity of the isolated strains to antibiotics and the carrying of drug resistance genes. The pathogenicity was evaluated by animal infection test. [Results] Bacterial isolation and culture were performed on 80 pig nasal swab samples. After morphological identification, 18 strains of suspected Klebsiella bacteria were initially isolated. After 16S rDNA sequencing and comparison analysis, three of the 18 strains were identified as K. oxytoca. 14 antimicrobial drugs from 10 classes were selected for drug sensitivity test, and threestrains of K. oxytoca were multidrug-resistant strains. The isolates were tested for 20 drug-resistant genes, and a total of 8 resistance genes were detected in the three strains of K. oxytoca, including bla_TEM, tetA, sul1, sul2, tetB, aac （3′）-IIa, aadA and qnrB. It was found that all the three isolates of acid-producing K. oxytoca could cause the death of mice and had strong pathogenicity. [Conclusion] The acid-producing K. oxytoca isolated from the large-scale pig farm showed multidrug resistance, carried multidrug-resistant genes, and had strong pathogenicity to mice. The results of this study provided basic data for the prevention and control of acid-producing K. oxytoca in this large-scale pig farm in Kuqa.

Key words: Klebsiella oxytoca, isolation and identification, drug resistance, pathogenicity, pig