Iron-uptake System of Staphylococcus aureus According to the Antibiotic Susceptibility / 감염

ABSTRACT

OBJECTIVE: It was reported that a few antimicrobial agents influenced on the activity of bacterial iron- uptake system (IUS). In the present study, we tried to investigate the relatedness between the resistance of antibiotics and the activity of the two high-affinity IUS, siderophore-mediated IUS and transferrin-binding protein (SA-tbp)-mediated IUS, of Staphylococcus aureus clinical isolates. METHODS: Total 71 strains including the standard ATCC 6538 strain were used. Seventy strains were isolated from the second or third line general hospitals from 1998 to 1999. Antimicrobial susceptibility test was performed by disk diffusion method. CAS agar diffusion assay was used for the measurement of staphylococcal siderophore. To visualize the expression of SA-tbp, Western blotting using human transferrin conjugated with horseradish peroxidase was performed. RESULTS: Among the nine antimicrobial agents, only the susceptible strains to oxacillin produced more siderophore compared to the resistant strains (P0.05). There were no antibiotics related to the expression of SA-tbp (P>0.05). CONCLUSION: These results indicate that only oxacillin (OXAC) influences on the production of staphylococcal siderophore and the further consecutive study about the action mechanism of OXAC is necessary.