Objective To investigate the distribution of integrons and the molecular characteristics of variable region resistance gene cassettes of integron-positive strains of Morganella morganii isolated from our hospital and their relationship with drug resistance.Methods Ninety-seven strains of non-replicated M.morganii clinically isolated from November 2015 to August 2021 at our hospital were collected and detected by PCR for class 1,2 and 3 integrons.Homology analysis of integron-positive strains was performed by ERIC-PCR.Results Among the 97M.morganii strains,28 strains were positive for class 1 integrons,accounting for 28.9％.Five strains were positive for class 2 integrons,accounting for 5.2％,of which one strain carried both class 1 and class 2 integrons,and no class 3 integrons were detected.PCR products were successfully amplified in the variable region of 26 of the 32 integron-positive strains.The drug resistance gene cassettes carried by the variable region of the class 1 integron-positive strains were mainly dfrA17-aadA5,and those carried by the variable regions of the class 2 integron-positive strains were mainly dfrA1-sat2-aadA1.The resistance rates of cotrimoxazole,ampicillin/sulbactam,ciprofloxacin were 90.6％,81.3％,78.1％,respectively,which were higher than those of integron-negative strains(P＜0.05).The 32 integron-positive M.morganii strains were mainly of two genotypes,A and B.Conclusion Variable regions of class 1 integrons in M.morganii mainly carry aminoglycoside and trimethoprim drug resistance gene cassettes and are highly correlated with host bacterial drug resistance,with high homology among integron-positive strains and possible intra-hospital clone and transmission.
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