Fluconazole susceptibilities of 150 Candida isolates were determined by a 25-g fluconazole disk diffusion agar test and compared with the microdilution NCCLS M27-A method. The agar test used three different media and was read at 24 and 48 h. When only the susceptible and nonsusceptible categories were used, disk diffusion with Müeller-Hinton agar supplemented with 2% glucose and 0.5 g of methylene blue (MHGM) per ml had a 95.37% correlation with the MIC method at 24 h, followed by RPMI 1640-2% of glucose agar (correlation, 94%) and Shadomy medium (SHDM) (correlation, 92.6%). The growth of microcolonies inside the inhibition zones was common (>63%) in the RPMI and SHDM media and minimal with MHGM (8.7%). At 48 h, MHGM and SHDM still had a >91% correlation with the MIC, while RPMI results had dropped to 75%. The best overall agreement was obtained with C. dubliniensis (100%).Fungal infection with Candida species is still an important cause of morbidity and mortality in immunocompromised patients. With the widespread use of fluconazole for the treatment and prevention of oropharyngeal and/or esophageal candidiasis, particularly in AIDS patients, clinical resistance is becoming a serious problem (5,7,8,12,21).What is needed is a rapid, easy, reproducible, and inexpensive in vitro method of obtaining susceptibility data which can guide the treatment of clinical yeast infections.The M27-A and M27-A2 reference NCCLS methods for antifungal susceptibility testing (15, 17) are cumbersome and costly, and reading the endpoints of the azoles is difficult. Alternative methods such as the broth microdilution adaptation of the M-27A and M27-A2 methods or the E test are simplified tests but are not easily adapted to the screening of yeasts for fluconazole susceptibility, nor are they cost-effective enough to be performed routinely in most clinical microbiology laboratories (6,18,20,24).Recent studies (2, 4, 9, 11, 13, 14, 19; C. Durussel, A. M. Daoui-Hassani, and J. Bille, Abstr. 38th Intersci. Conf. Antimicrob. Agents Chemother., abstr. J120, 1998) have demonstrated that an agar disk diffusion method similar to that used for testing antibacterial agents (NCCLS M2-A6) (16) can reproducibly and accurately determine the susceptibility of yeasts to fluconazole and can easily be incorporated into a clinical laboratory as an effective means for fluconazole susceptibility screening.The aim of this report is to study the agreement between the broth microdilution NCCLS method and a 25-g fluconazole disk diffusion test performed using RPMI 1640-2% glucose agar (RPMIG), Müeller-Hinton agar supplemented with 2% glucose and 0.5 g of methylene blue (MHGM) per ml, and Shadomy medium (SHDM).A total of 150 isolates of Candida spp. were collected from the clinical microbiology laboratory of Hospital Clínico Universitario Lozano Blesa (Zaragoza, Spain) and submitted for fluconazole susceptibility testing by microdilution and agar diffusion. The Candida species tested were 63 C. albicans isolates, 25 C. dubliniensis isolates, 25 C. glabrata isolat...

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This study determines the optimal number of faecal samples that should be examined in order to minimize the occurrence of false-negative results in the diagnosis of cryptosporidiosis using routine techniques. A total of 23,023 faecal samples from 10,870 patients submitted for parasitological examination were processed by the formalin-ethyl acetate concentration technique and stained using a modified Ziehl-Neelsen method. Cryptosporidiosis was diagnosed in 232 patients (2.13%), 44 of whom were infected by HIV, the prevalence rate in this population group being 15.54%. The increase in the number of diagnoses obtained by the examination of n and (n-1) specimens was evaluated statistically. This study found that three is the optimal number of faecal samples that should be examined when cryptosporidiosis is suspected in immunocompetent patients; whereas, only two samples are required for diagnosing this protozoosis in AIDS patients.

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