IN-VITRO ACTIVITY OF SCH-56592 AND COMPARISON WITH ACTIVITIES OF AMPHOTERICIN-B AND ITRACONAZOLE AGAINST ASPERGILLUS SPP

In this study, we investigated the in vitro activity of SCH-56592 (SCH ), a new triazole antifungal agent, We compared the activity of SCH wi th those of itraconazole (ITZ) and amphotericin B (AB) against 60 clin ical isolates of Aspergillus spp, by using a microtiter format, Incuba tion was done at 37 degrees C for 48 h, and MIC endpoints (no growth) were read visually, The medium used for all of the drugs was RPMI 1640 buffered with morpholinepropanesulfonic acid (MOPS) and supplemented with 2% glucose, MICs and minimum fungicidal concentrations (MFCs; kil ling of greater than or equal to 99.99%) were measured for all isolate s, The geometric mean (GM) MICs and ranges (in micrograms per millilit er) sere as follows: SCH, 0.09 and less than or equal to 0.01 to 1; IT Z, 0.25 and 0.06 to 32; AB, 1.46 and 0.25 to 32, Aspergillus terreus ( n = 7) was markedly more susceptible to SCH (GM, 0.05 mu g/ml) and ITZ (GM, 0.07 mu g/ml) than to AB (GM, 8.8 mu-g/ml). For all isolates, th e GM MFCs and ranges (in micrograms per milliliter) were as follows: S CH, 3.64 and 0.125 to 16; ITZ, 15.09 and 0.125 to 32; AB, 10.3 and 1 t o 32, In the drug concentration range tested, 71, 32, and 64% of the i solates against which SCH, ITZ, and AB, respectively, were tested were killed, A reproducibility study was performed with 20% Of the isolate s; for 11 of the 12 isolates retested, the MIC was the same or within 1 well of the original MIC of each drug, Therefore, in vitro mould tes ting of SCH is feasible and reproducible, SCH was found to be very act ive against all species of Aspergillus and at loser concentrations tha n either ITZ or AB.