MW4412 Maeski

Persistent or recurrent oropharyngeal candidosis (OPC) caused by Candida albicans is common in patients with AIDS. Fluconazole has been used widely to treat OPC, but several publications have described its failure in the treatment of patients with advanced AIDS, particularly when used over a long period of time. 3 The Subcommittee for Antifungal Susceptibility Testing of the National Committee for Clinical Laboratory Standards (NCCLS) has collaborated with many other investigators to develop the Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts. Now, NCCLS has published its approval-level version as document M27-A. Interpretive breakpoints were proposed for the antifungal testing of Candida spp. with fluconazole by the NCCLS M27-T broth macrodilution method, with MICs of 64 mg/L indicating resistance. The trailing growth phenomenon remains a problem in antifungal testing of certain yeast isolates by the NCCLS method. The M27-A method addressed this problem by requiring an 80% reduction in growth after 48 h of incubation; MICs are several dilutions above the 24 h results. The development of another test for the detection of azole-resistant C. albicans strains may be helpful for the clinical laboratory. Many studies have investigated the mechanisms of azole resistance in C a n d i d a spp. isolates. – 9 The results of these studies indicate that resistance to azole antifungal agents may be a consequence of one or more mechanisms. One of the major mechanisms imparting resistance to azole antifungal agents can be drug efflux, similar to the multidrugresistant (MDR) pumps in tumour cells. Among the MDR genes, C D R 1 has been cloned in C. albicans and the level of mRNA of the C D R 1 gene was found to be signific a n t l y higher in fluconazole-resistant strains than in sensitive s t r a i n s . 0 The product of another C. albicans gene, C a M D R 1, formerly known as B E N, resembles proteins of the major facilitator superfamily (MFS) class of MDR proteins. 1