DETECTION OF CANDIDA-DUBLINIENSIS IN OROPHARYNGEAL SAMPLES FROM HUMANIMMUNODEFICIENCY VIRUS-INFECTED PATIENTS IN NORTH-AMERICA BY PRIMARY CHROMAGAR CANDIDA SCREENING AND SUSCEPTIBILITY TESTING OF ISOLATES

Candida dubliniensis has been associated with oropharyngeal candidiasi s in patients infected with human immunodeficiency virus (HIV), C, dub liniensis isolates may have: been improperly characterized as atypical Candida albicans due to the phenotypic similarity between the two spe cies. Prospective screening of oral rinses from 63 HIV-infected patien ts detected atypical dark green isolates on CHROMagar Candida compared to typical C, albicans isolates, which are light green, Forty-eight a typical isolates and three control strains were characterized by germ tube formation, differential growth at 37, 42, and 45 degrees C, ident ification by API 20C, fluorescence, chlamydoconidium production, and f ingerprinting by Ca3 probe DNA hybridization patterns. All isolates we re germ tube positive, Very poor or no growth occurred at 42 degrees C with 22 of 51 isolates. All 22 poorly growing isolates at 42 degrees C and one isolate with growth at 42 degrees C showed weak hybridizatio n of the Ca3 probe with genomic DNA, consistent with C. dubliniensis i dentification. No C. dubliniensis isolate but only 18 of 28C, albicans isolates grew at 45 degrees C, Other phenotypic or morphologic tests were less reliable in differentiating C, dubliniensis from C, albicans , Antifungal susceptibility testing showed fluconazole MICs ranging fr om less than or equal to 0.125 to 64 mu g/ml. Two isolates were resist ant to fluconazale (MIC, 64 mu g/ml) and one strain was dose dependent susceptible (MIC, 16 mu g/ml). MICs of other azoles, including vorico nazole, itraconazole, and SCH 56592, for these isolates were lower. C, dubliniensis was identified in 11 of 63 (17%) serially evaluated pati ents, Variability in phenotypic characteristics dictates the use of mo lecular and biochemical techniques to identify C, dubliniensis, This s tudy identifies C, dubliniensis in HIV-infected patients from San Anto nio, Tex,, and shows that C, dubliniensis is frequently detected in th ose patients by using a primary CHROMagar screen.