Candidosis in the intensive care unit: a 20-year survey.

Deep-seated candidosis is a major problem in critically ill patients. Colonization with candida has been identified as an important independent risk factor for the development of candidaemia. Since the 1980s routine surveillance cultures have been performed on patients admitted for six or more days to the 'E. Vecla' intensive care unit (ICU) of the IRCCS Ospedale Maggiore di Milano. Colonization was observed on admission to the ICU in 59 of 117 (50%) patients in 2000 and 10 others developed colonization during their stay on the unit. A similar colonization rate was found in a survey performed 16 years earlier. The incidence of non-albicans Candida species, however, increased in 2000. In particular, 24 patients were culture positive for Candida glabrata at some point during their hospital stay, whereas this species was isolated from only one patient in 1983-1984. Antifungal susceptibility testing performed by Sensititre Yeast One revealed no resistance among 19 C. albicans strains tested. In contrast, fluconazole resistance was observed in two of 39 (5%) C. glabrata isolates from 23 patients. In the period 1983-2002, 28 candida bloodstream infections were identified and 12 were considered to be ICU-acquired (2.6/1000 hospitalized patients; 0.33/1000 patient days). The low rate of ICU-acquired candidaemia despite the inclusion of severely compromised patients in this study confirms the usefulness of routine mycological surveillance in preventing deep-seated candidosis.

Effect of medium composition on static and cidal activity of amphotericin B, itraconazole, voriconazole, posaconazole and terbinafine against Aspergillus fumigatus: a multicenter study.

The effect of the medium composition on the fungistatic (MIC) and fungicidal (MLC) activity of amphotericin B, itraconazole, voriconazole, posaconazole and terbinafine against four Aspergillus fumigatus strains has been investigated by four European laboratories. MICs were determined by broth microdilution, using RPMI 1640 and Antibiotic Medium 3 (AM3), three times in three independent determinations by the four laboratories. MLCs were determined for the three independent determinations by the four laboratories, subculturing 100 microl from each well showing no visible growth after 48 hours. Except for a 2-dilution difference observed in three cases, no differences were observed between MICs determined on the two media. In contrast, a 3- to 6-dilution discrepancy between the MLCs was observed for the azoles. Endpoints on RPMI were higher than those on AM3. A 1-2 dilution difference was noted between both the endpoints of amphotericin B and of terbinafine. The highest inter- and intra-laboratory agreements were reached on AM3. The azoles showed a medium-dependent fungicidal activity.

Comparison of three methods for testing azole susceptibilities of Candida albicans strains isolated sequentially from oral cavities of AIDS patients.

Three susceptibility testing procedures were compared to determine fluconazole, itraconazole, and ketoconazole MICs against 47 Candida albicans strains isolated sequentially from the oral cavities of five AIDS patients undergoing azole therapy. They included the broth microdilution method (BM), performed according to the National Committee for Clinical Laboratory Standards' tentative standard, the agar dilution method (AD), and the Etest; the latter two tests were performed both in Casitone agar (AD-Cas and Etest-Cas) and in RPMI (AD-RPMI and Etest-RPMI). Twenty-four- and 48-h MICs obtained by AD and Etest were compared with 48-h MICs obtained by BM. The MICs of all the azoles determined by BM were usually lower than those obtained by the other methods, mainly due to different reading criteria. In order to assess the most appropriate way of evaluating the agreement of MICs obtained by different methods with those produced by the proposed reference method (BM), we used the mean differences calculated according to Bland and Altman's method. Comparison of fluconazole MICs obtained by BM and AD-Cas yielded a mean difference of 3, and the percentages of agreement within +/-2 dilutions were 98 and 100% at 24 and 48 h, respectively. For ketoconazole and itraconazole MICs, lower mean differences were noted, and agreement ranged from 96 to 100%. Agreement between the AD-RPMI and BM results was poor for all azoles, and an increase in MICs was always observed between the 1st- and 2nd-day readings. Similarly, Etest-Cas gave better agreement with BM than did Etest-RPMI for all the azoles. BM, AD-Cas, and Etest-Cas each demonstrated a progressive increase in fluconazole MICs against strains isolated sequentially from a given patient, in accordance with the decreased clinical response to fluconazole.

Prevalence of serotype D in Cryptococcus neoformans isolates from HIV positive and HIV negative patients in Italy.

Cryptococcus neoformans strains isolated from 207 HIV positive and HIV negative patients hospitalized in Northern Italy were serotyped by slide agglutination. One Brazilian HIV negative woman was infected by var. gattii serotype B and all the other patients by var. neoformans, serotype D in 71%, serotype A in 24.6% and serotype AD in 3.4%. No difference was observed between subjects with serotypes A and D in HIV coinfection, exposure categories for AIDS, age, sex, and CD4 count of HIV positive patients. Meningeal and respiratory tract involvements and prostatic reservoir occurred with comparable frequency in AIDS patients infected by serotypes A and D. Skin lesions were observed only in serotype D infections, occurring in 12.6% of HIV positive and 58.3% of HIV negative patients infected by this serotype. Serotype A was found less susceptible to fluconazole than serotype D: 53.7% of serotype A strains had a MIC > or = 25 micrograms ml-1 compared to 17.7% of the serotype D isolates. On the other hand, both serotypes were highly susceptible to itraconazole.