Candida (Torulopsis) glabrata: a 19-year epidemiological study in a university hospital; susceptibility

Introduction. The emergence of non-albicans Candida species, such as Candid a (Torulopsis) glabrata, calls for epidemiologic and colonization studies. Identifying the isolate species and evaluating their susceptibility would l ead to early, specific treatment of infections. Objective. We retrospectively studied the incidence of C. glabrata and its evolution between 1980 and 1998 in a university hospital (C.H.U. Nord, Mars eille, France). We investigated different body sites in units following or not the colonization. We also presented the susceptibility of 63 C. glabrat a strains to amphotericin B, flucytosine, itraconazole, and fluconazole. Methods. The 16 years were divided into 4 periods (I: 1980-1983, II: 1984-1 987, III: 1988-1993, IV: 1994-1998) according to collection methods and con trol programs. Yeast isolates, both colonizing and pathogenic, were collect ed in this hospital without units for highly immunocompromized patients. Fl uconazole prophylactic treatment is not used; rather, since 1991, there has been selective decontamination of the digestive tract with amphotericin B in intensive care units for polytraumatized patients with ventilatory suppo rt. The isolates were identified by microscopic and macroscopic morphology, and the physiological characteristics were determined by different commerc ially available kits. The susceptibility of strains to amphotericin B and f lucytosine was evaluated by the ATB-fungus (R) system, and that of itracona zole and fluconazole by Etest (R). Results. Over the 16 years, the progress in techniques did not affect the i ncidence of C. glabrata. Although awareness grew, in particular from 1988 w hen intensive care units started monitoring colonization, the frequency of isolates in the various body sites was similar for period I relative to oth er periods, except for urine and genital samples. Globally C. glabrata was the second most frequent species. Its frequency increased by increments, fr om 8.95 % (period I) to 7.57 % 8.80 %, and to 10.74 %, respectively for the other 3 periods. For body sites, the emergence of C. glabrata is clearer, with a progressive increase in the number of body sites for which C. glabra ta is the second most common species following Candida albicans. Among the 5 body sites for which C. glabrata incidence was the second highest, the fr equency exceeded 10 % at deep levels as well as genital and urinary tracts. The frequency of the various species in the intensive care units was close to that in the hospital as a whole. In contrast, the frequency of some spe cies in pediatric intensive care units and in gynecology-obstetrics unit di ffered from that of the overall hospital population. All the strains tested were susceptible to amphotericin B and flucytosine. Seventy-nine per cent of the strains had a fluconazole MIC between 2 and 16 mg/l and 73 % an itra conazole MIC less than or equal to 2 mg/l. Eighty per cent of the strains r esistant to fluconazole were cross resistant to itraconazole. Conclusion. Even if C, albicans remains by far the most frequently found sp ecies, C. glabrata has become the second most common species in our hospita l, as reported for other treament centers where patients were at a high ris k for fungal infections. The increase of the incidence of C. glabrata in ad ults was due neither to fluconazole prophylactic treatment nor to selective decontamination of the digestive tract. This higher incidence probably res ults from modification of the flora of the gastrointestinal and genital muc osa because of physiological and extrinsic risk factors such as the adminis tration of antibacterial agents, immunodepressants, or catheterization. Per haps also involved is the dietary intake of yeasts or antibacterial or anti fungal agents. Studies should be done on the pathophysiology of this specie s to better understand how it causes such severe infections in deeply debil itated patients. For C. glabrata, the fluconazole MIC must be established t o determine the adequate treatment and dosage.