Analysis of the effect of integrons on drug-resistant Staphylococcus aureus by multiplex PCR detection.

The aim of this study was to detect class Ⅰ, II and III integrons using multiplex PCR, and to analyze the role that these integrons play in mediating multidrug-resistant Staphylococcus aureus (SA). The sensitivity of SA to 20 types of antibiotics was examined using the K-B method. A genomic DNA extraction kit was used for extracting genomic DNA and a high-purity 96 plasmid extraction kit was used for extracting plasmid DNA. Class Ⅰ, II and III integrons were amplified using multiplex PCR. Agarose gel electrophoresis was used for analysing amplification products. The positive rate of class Ⅰ and II integrons in the plasmid DNA from SA was higher compared to that of the genomic DNA. The positive rate of class Ⅰ integrons was highest in the group with multidrug resistance to amoxicillin/clavulanic acid, piperacillin/tazobactam, ciprofloxacin, tetracycline, rifampin, imipenem, cefazolin, cefuroxime, levofloxacin and gentamicin. As regards integron detection in the plasmids from drug-resistant SA strians obtained from sputum, blood, cerebrospinal fluid, drainage fluid, excretion and urine specimens, the difference in the detection rate of class Ⅰ integrons among the six types of specimens was significant. Multiplex PCR is an effective method to detect class Ⅰ, II and III integrons. The SA plasmid is the main carrier transferring integrons. Integrons mediate the formation of SA multidrug resistance.