Yeasts isolated from intensive care unit patients and their susceptibilities against antifungal agents

2. SUMMARY Yeasts Isolated From Intensive Care Unit Patients and Their Susceptibilities Against Antifungal Agents Due to the advances in medical and surgical treatment, new therapy technologies such as organ transplantions and invasive diagnostic methods, the number of the patients who are at risk for developing opportunistic fungal infections has increased. Intensive care units (ICU) are the services where the highest nosocomial infection rates are detected. Patients who are hospitalized in these services are at greater risk for developing opportunistic fungal infections. Candida spp. are the most frequent species that are isolated from these infections. It is important to determine species distribution, susceptibility patterns and resistance rates of the yeast isolates recovered from ICU patients as yeast species show discrepancies about virulence and resistance to antifungal agents and cause infections with high mortality and morbidity. In our study, identification of 113 yeast isolates recovered from clinical specimens of ICU patients had been performed by investigating colony morphology, germ tube formation, microscopic morphology on corn meal agar with Tween 80 and activity of urease. Susceptibilities of the isolates to amphotericin B, fluconazole, itraconazole and ketoconazole had been determined with microdilution technique done according to the standards of NCCLS M27-A. Fifty five of 1 1 3 yeast isolates had been identified as C. albicans, 22 as C. glabrata, 13 as C. tropicalis, seven as Trichosporon spp., six as C. parapsilosis, four as C. /cruse/, three as C. guilliermondii, two as C. kefyr and one as G. candidum. According to the results of antifungal susceptibility tests, MIC ranges for amphotericin B, fluconazole, itraconazole and ketoconazole were between 0.06-1 ug/ml, 0.125-64 ug/ml, 0.015-8 ug/ml and 0.03-8 ug/ml, respectively. While no resistance against amphotericin B had been detected among our isolates, the4 resistance rates for. fluconazole and itraconazole among Candida spp were 8.6%- and 13.3% respectively. As a result, we conclude that identification and detection of antifungal susceptibilities of the yeast isolates recovered from ICU patients are essential. According to our results, we can say that amphotericin B is still an effective antifungal agent. The increase in the incidence of C. glabrata isolation and the detection of high rate of resistance against azoles among this species are important. Although resistance against azoles were detected among Candida species other than C. glabrata, we think that azoles can still be used in treatment when it is evaluated together with identification results. Key words: Intensive care unit, yeasts, antifungal susceptibility, microdilution method