|
 |
 Home > Available Issues |
|
|
 Original Articles |
| Antimicrobial susceptibility of Stenotrophomonas maltophilia |
| Yeon Joon Park, Myung Shin Kim, Byung Kee Km, Sun Moo Kim, and Sang In Shin |
| Department of Clinical Pathology, Catholic University of Korea, College of Medicine, Seoul, Korea |
Vol.15 Num.4 (p403~409)
|
|
|
Background : In recent years, a significant increase in the incidence of Stenotrephomonas maltophilia has occurred. In addition to antimicrobial pressure, long-term hospitalization and catheterization are contributory factors to the increased S. maltophilia isolation rate. Dilution method is recommended for antimicrobial susceptibility testing, but it is not practical in clinical microbiology laboratories. In this study, we compared the disk diffusion, commercial microbroth dilution(Microscan) and agar dilution methods in testing antimicrobial susceptibility of S. maltophilia.
Methods : We compared antimicrobial susceptibility data of 6 tertiary-care hospitals using disk diffusion or Microscan(Dade International Inc., USA). We tested the susceptibility of 19 clinical isolates to four antimicrobials(trimethoprim-sulfa-methoxazole, ticarcillin-clavulanate, ciprofloxacin, doxycycline) which are known to be active for S. maltophilia.
Results : From the comparison of antimicrobial susceptibility of 6 tertiary-care hospitals using disk diffusion or commercial microbroth dilution method, the disk diffusion method revealed higher susceptibility rates in aminoglycosides, ceftazidime and ciprofloxacin. From the comparison of disk diffusion and agar dilution methods, trimethoprim-sulfamethoxazole disk showed excellent predictive values. The 24h disk diffusion method the activity of ciprofloxacin(11 % very major errors, 4% minor errors). The nine strains which showed minor errors coincided with the agar dilution method after 4%h incubation. With ticarcillin-clavulanate, the 24h disk diffusion method revealed 5% major errors and 63% minor errors, which did not change after 48h. From the comparison of microscan and agar dilution method, 5% major errors and 11% minor errors were observed for ciprofloxacin. For ticarcillin-clavulanate, 5% major errors and 47% minor errors were observed.
Couclusion : In testing antimicrobial susceptibility of S. malatophilia disk diffusion and microdilution methods need to be modified in order to better correlate with agar dilution method.
|
|
|
Keywords : Stenotrophomonas maltophilia, antimicrobial susceptibily, disk diffusion, microbroth dilution, agar dilution |
|
|
|
|
|
|
|
|
