Abstract:

Objective To investigate the distribution and drug resistance characteristics of Bacteroides，and to investigate the genotyping characteristics of bft gene in Bacteroides fragilis. Methods Totally，147 isolates of Bacteroides were collected from the Affiliated Hospital of Inner Mongolia Medical University from June 2016 to June 2019，and they were identified by in vitro drug susceptibility test. Polymerase chain reaction（PCR） was used to determine bft gene in Bacteroides fragilis. Results In the 147 isolates of Bacteroides，100 isolates of Bacteroides fragilis were determined，accounting for 68.0%，25 isolates of Bacteroides thetaiotaomicron accounted for 17.0%，and 9 isolates of Bacteroides ovalis accounted for 6.1%. The highest drug resistance rate of Bacteroides was 78.9% to clindamycin. The clindamycin resistance rate for Bacteroides fragilis was 85.0%，which was higher than those of other Bacteroides（66.0%）. Imipenem and meropenem resistance rates were 13.6% and 4.7% for Bacteroides，respectively. Bacteroides showed different degrees of resistance to other drugs，and the most drug resistance rates of Bacteroides fragilis to drugs were higher than those of other Bacteroides. The positive rate of bft gene was 38.0% in Bacteroides fragilis. The main genotype was bft-1（28.0%），followed by bft-2（10.0%），and no bft-3 was found. The positive rate of bft gene of Bacteroides fragilis isolated from non-abdominal specimens（55.6%） was higher than that of Bacteroides fragilis isolated from abdominal specimens（36.3%）. Conclusions Bacteroides fragilis has the highest isolation rate in Bacteroides，and it has certain resistance to common clinical drugs. The prevalence of enterotoxin-producing isolates of Bacteroides fragilis isolated from non-abdominal specimens is higher，which should be widely paid attention in clinic.

Key words: Bacteroides, Bacteroides fragilis, Drug resistance, bft gene