Relationship between integrons and antibiotic resistance of Salmonella isolated from food

  Objective   To investigate the relationship between antibiotic tesistance of Salmonella spp strains isolated from food and the integrons they harbored.

  Methods   PCR amplifying intI gene and the variable region between the conserved segments(CS-PCR)were performed for class 1, class 2, and class 3 integr on.And the integr on content of every isolate was characterized by restriction fragment length polymorphisms(RFLP)analysis and sequencing.

  Results   25 of 69 isolates were identified as being positive for integrase 1 gene in the total DNA.Most of the integron-positive strains were resistant to more than 4 antibiotics.Most of the gene cassettes integrated in the integrons conferred resistant against trimethoprim and streptomycin-spect inomycin, and the integrons with the dfr 1-aadA 1 gene cassettes combination were predominant.

  Conclusion   There is a good correlation between integron-carrying and the antibiotic resistance of Salmonella spp strains isolated from food.