Isolation of the drug-resistant Staphylococcus aureus strains from burn wound flora and analysis of norA genetic mutation / 中华创伤杂志

ABSTRACT

Objective To investigate the genetic mutation of the norA gene and its promotor from the wild-type drug-resistance Staphylococeus aureus(S.aureus)strains. Methods A total of 10 antibiotic-resistant S.aureus strains were isolated and screened from the burn wound for the sequencing and analysis of the nora gene and its promoter. Results There isolated 87 S.aureus strains from the burn wound flora,which were completely sensitive to vacomycin,highly sensitive to Quinupristin and Nitrofurantoin,but highly resistant to the other antibiotics,even up to91.7% of MRSA.There found the same point mutation(G→A) located at 1 349 sites of the norA gene coding region in all the S.aureus strains,saying that the amino acid was changed from Gly(glycin)to Asp(agpartic acid) in 291 sites.The resetpine reverse test showed that the MICs value of three antibiotics was lowered at various degrees in all 10strains.Conclusion NorA gene mutation is one of the mechanisms for antibiotic-resistance of S.aureus.