ABSTRACT
OBJECTIVE To understand the epidemic condition on the resistant plasmids and their homology of the Staphylococcus aureus obtained from two hospitals in Gansu Province.METHODS The antibiotic sensitivity test,plasmid elimination,plasmid profile,and restriction endonuclease profile were used in analyzing the S.aureus resistant plasmids.RESULTS We isolated 15 strains of S.aureus from 196 samples in two different hospitals,the isolation rate was 7.7%.From them 86.7% isolates were resistant to the seven commonly used antibiotics in different degree.Only 13.3% strains were just resistant to one antimicrobial,the multi-resistant strains amounted for 46.7%.There were 12 isolates carried plasmids(80.0%).The results of plasmid elimination showed 11 strains carried resistant plasmids,and the one with 38 kb was a popular plasmid.The endonuclease profiles revealed that the same source strains had certain homology,there were similiar endonuclease profiles among strains in different wards.CONCLUSIONS The popular plasmids in different wards have certain homology,and they can be transferred among different strains of bacteria.