Role of yeasts as nosocomial pathogens & their susceptibility to fluconazole & amphotericin B

A total of 213 and 208 yeasts were isolated as nosocomial pathogens from va rious infected specimens during 1996 and 1997 respectively. Yeasts ranked f ifth among uropathogens in both the years and from eighth to eleventh in ot her specimens. Increasing trend in nosocomial urinary tract yeast infection (11.9 in 1996 to 12.6 in 1997) and decreasing trend in wound and other inf ections (5.1 in 1996 to 2.9 in 1997) per 1000 patients' discharges were obs erved; blood stream infection remained unchanged (2/1000 discharges) in bot h the years. Eighty two (41 from each year) randomly selected yeasts were i dentified to species level following standard protocol and tested for antif ungal susceptibility against fluconazole and amphotericin B by reference br oth macrodilution technique and agar dilution (AD) method. The frequency of various yeast species identified was Candida albicans 39 (47.6%), C. tropi calis 29 (35.4%), C. krusei 4 (4.9%), C. glabrata 3 (3.7%), C: zeylanoides 2 (2.4%), C. guilliermondii 2 (2.4%), one strain (1.2%) each of C. kefyr, C . parapsilosis, and Trichosporon beigelii. Resistance to fluconazole (MIC g reater than or equal to 64 mu g/ml) as per NCCLS criteria was observed in 2 Candida sp; (2.4%). Significantly higher number of non-albicans Candida sp . (8/43; 18.6%) had MIC > 8 mu g/ml as compared to C. albicans (2/39; 5.1%) (P < 0.05). Only one strain of C. tropicalis had MIC 8 mu g/ml to amphoteri cin B and none had MIC > 8 mu g/ml. Agreement between the reference and the AD methods for fluconazole was 88 per cent and for amphotericin B was 94 p er cent. The present study indicates that Candida sp. are emerging as impor tant nosocomial pathogens and the tendency of yeasts to develop resistance to antifungal agents appears to be a challenge for patient management.