OBJECTIVETo investigate the characteristic of integrons and the relationship between integrons and antimicrobial resistance in Shigella spp.

METHODSNinety Shigella strains (83 S. flexneri and 7 S. sonnei) were isolated from the stools of patients in China. Susceptibility to 8 antimicrobials was tested for all isolated strains. PCR, RFLP and sequencing analysis of integrons were applied to all of them.

RESULTSHigh prevalence of multi-drug resistance (95.6%) was identified. Of the isolates 79 (87.8%) carried integrase genes of class 1 integron (3.3%), class 2 integron (10.0%) or both (74.4%). No intI3 was detected in the tested isolates. The prevalence of intI2 was significantly higher in isolates with multi-drug resistance to at least 3 antibiotics than that in isolates with resistance to 2 and less antibiotics (P<0.05). Gene cassettes dfrA17-aadA5, dfrA12-orfF-aadA2 of class 1 integron and dfrA1-sat1-aadA1 of class 2 integron were identified.

CONCLUSIONThe class 2 integron may play a role in the emergence of multi-drug resistance in Shigella spp.

Base Sequence ; China ; DNA Primers ; Drug Resistance, Microbial ; Drug Resistance, Multiple ; Integrons ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Shigella ; drug effects ; genetics