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.

Fluconazole susceptibility and strain variation of Candida albicans isolates from HIV-infected patients with oropharyngeal candidosis

Over a 16 month period we conducted a prospective study in a cohort of 45 HIV-positive patients to detect the development of resistance to fluconazole and to analyse the epidemiology of oropharyngeal candidosis (OPC). Each episode was treated with fluconazole 100 mg/day po for 10 days. All yeast isolates were tested for their in-vitro susceptibility to fluconazole. Multiple strains of Candida albicans simultaneously isolated from a given patient were typed by electrophoretic karyotyping. Overall, 106 episodes of OPC were diagnosed among the 45 patients: 18/45 patients (40%) had only one episode, 11/45 (24%) had two episodes, and the remaining 16/45 (36%) had three or more episodes (range 3-7). Cure (complete resolution of signs and symptoms and negative post-treatment cultures) and improvement (complete resolution of signs and symptoms but positive post-treatment cultures) were observed in 30/106 (28%) and 69/106 (65%) episodes of OPC, respectively. Failure (absence of improvement or exacerbation of signs and symptoms) was observed in seven episodes (7%) from four patients. In two of these four patients a significant and progressive increase in fluconazole MICs was observed: from 0.25 to 16 mg/L in one patient, and from < or = 0.125 to 32 mg/L in the second one. Tests on multiple colonies from individual isolation plates showed that it was not unusual to obtain different fluconazole MICs, indicating that, in order to avoid misleading results, one should perform in-vitro susceptibility testing by using a multiple colony inoculum rather than an inoculum made from a single colony. A total of 213 strains of C. albicans isolated from seven patients who suffered from four or more episodes of OPC through the course of the study were typed by electrophoretic karyotyping. Five individuals (71%) were infected with yeasts with only one DNA type, while the other two patients showed the presence of two or three different DNA types. The simultaneous presence of multiple types was found only in one of the seven subjects. Our data confirm the efficacy of fluconazole 100 mg/day for the treatment of OPC in HIV patients. Isolation of fluconazole-resistant strains of C. albicans with this regimen is rare. The vast majority of HIV patients are infected with a unique strain of C. albicans throughout each episode of infection. A minority of patients, however, can harbour strains of C. albicans with variable patterns of fluconazole susceptibility simultaneously.

In-vitro interaction of terbinafine with amphotericin B, fluconazole and itraconazole against clinical isolates of Candida albicans

A chequerboard titration broth microdilution method, performed according to the recommendations of the National Committee for Clinical Laboratory Standards, was applied to study the in-vitro interaction of terbinafine with amphotericin B, fluconazole and itraconazole against 30 strains of Candida albicans isolated from the oral cavities of AIDS patients. MICs were determined spectrophotometrically at 490 nm and read at either 24 h or 48 h. The end-point was defined as the drug concentration resulting in > or = 90% inhibition of growth relative to control growth. Synergy, defined as a fractional inhibitory concentration (FIC) index of < or = 0.50, was observed in 93% (28 of 30) of terbinafine-amphotericin B interactions, in 47% (14 of 30) of terbinafine-fluconazole interactions and in 43% (13 of 30) of terbinafine-itraconazole interactions; antagonism (FIC > 2.0) was not observed. Where synergy was not achieved, there was still a decrease, although not as dramatic, in the MIC of one or both drugs when used in combination. Reading the MICs on day 2 did not significantly affect the mode of interaction of terbinafine-triazoles, while for terbinafine-amphotericin B the proportion of synergic interactions dropped from 93% (28 of 30) to 30% (nine of 30; P = 0.0001). Antagonism was not observed for any drug combination even at 48 h. Minimum fungicidal concentrations (MFCs) of all drugs alone and in combination were determined against five isolates. Neither terbinafine nor the two triazoles showed fungicidal activity when tested alone or in combination. The fungicidal activity of amphotericin B was slightly enhanced when combined with terbinafine, there being a decrease of two-fold dilutions in the amphotericin B MFCs against all five isolates tested. Thus terbinafine enhances the activities of amphotericin B and triazoles against C. albicans in vitro. Clearly, clinical studies are warranted to elucidate further the potential utility of these combination therapies.

In vitro activities of terbinafine in combination with fluconazole and itraconazole against isolates of Candida albicans with reduced susceptibility to azoles

A checkerboard microdilution method was applied to study the in vitro interaction of terbinafine with either fluconazole and itraconazole against 30 strains of Candida albicans. Synergy was observed in 40% of the terbinafine-fluconazole interactions and in 43% of the terbinafine-itraconazole interactions, while antagonism was not observed. Even when only additivity was achieved, the combinations still showed beneficial effects since at least twofold reductions in the MICs of both drugs were found in 100% of the terbinafine-fluconazole interactions and in 76% of the terbinafine-itraconazole interactions.

Genotypic identification of sequential Candida albicans isolates from AIDS patients by polymerase chain reaction techniques

Random amplification of polymorphic DNA and inter-repeat polymerase chain reaction (IR-PCR) were compared with restriction fragment length polymorphism (RFLP) analysis as methods for DNA typing of Candida albicans. Forty-seven strains of Candida albicans isolated from the oral cavities of five AIDS patients undergoing fluconazole therapy were analyzed. There was an excellent correspondence between the DNA types obtained by both PCR-based techniques and by RFLP. With the exception of one patient who was infected with three DNA types of Candida albicans during a five-year observation period, the patients each harboured only one major strain, which became progressively less susceptible to fluconazole. Each DNA type was unique to a patient. The data suggest that these typing methods are suitable for investigating the epidemiology of oropharyngeal candidiasis in this patient group.

Variation in fluconazole efficacy for Candida albicans strains sequentially isolated from oral cavities of patients with AIDS in an experimental murine candidiasis model

Four strains of Candida albicans, isolated from two patients with AIDS who had undergone prolonged fluconazole therapy for oral candidiasis, were studied in a model of disseminated murine candidiasis. Pre- and posttreatment isolates from each patient were genetically related, and the fluconazole MICs for the strains had increased significantly, from 0.25 to 32 micrograms/ml for the strains isolated from patient 1 and from 1.0 to 16 micrograms/ml for the strains isolated from patient 2. Mice were infected intravenously and were treated orally with fluconazole. For survival studies, mice were treated from day 1 to day 10 postinfection and were observed through day 30. The fluconazole dosages were as follows: 0.25, 0.5, 1.0, and 5.0 mg/kg of body weight twice a day. For tissue burden studies, two groups of mice (each group received fluconazole at 0.25 or 5.0 mg/kg) were treated from day 1 to day 7 and were sacrificed 1 day later for quantitative tissue cultures of the spleen and both kidneys. For pretreatment isolates from both patients, all fluconazole dosing regimens were effective at prolonging survival compared with the survival of the control groups. For posttreatment isolates, only fluconazole at 5.0 mg/kg was effective at prolonging survival. Both fluconazole dosing regimens used in the tissue burden studies significantly reduced the counts of the pretreatment isolate from patient 1 in the spleen and kidney, while fluconazole at 5.0 mg/kg was effective at reducing the counts of the posttreatment isolate. For both isolates from patient 2, only fluconazole at 5.0 mg/kg was effective at reducing the counts in the spleen and kidney. The study indicates that C. albicans mutation to resistance to fluconazole may play a critical role in fluconazole-refractory oral candidiasis in AIDS patients.

Electrophoretic karyotype and in vitro antifungal susceptibility of Cryptococcus neoformans isolates from AIDS patients

Electrophoretic karyotype (EK) was used to type 13 clinical isolates of Cryptococcus neoformans from eight AIDS patients. All of the isolates were also tested for their in vitro susceptibilities to fluconazole, itraconazole, D0870, flucytosine, and amphotericin B by a broth macrodilution technique performed according to the National Committee for Clinical Laboratory Standards recommendations. Although all strains were isolated from a limited geographic area, DNA typing showed a wide genetic variation in this group of patients, yielding seven different patterns. Two patients in whom C. neoformans was isolated in the same time period shared similar EK profiles, suggesting the possibility of cross-infection. In three patients, sequential isolates were evaluated: in two of them, EK analysis showed the persistence of the same genotype throughout the infection, whereas from the third, two isolates of C. neoformans with two different DNA profiles were obtained. Despite the small number of strains considered in this study, our susceptibility data indicate that C. neoformans isolates are very susceptible to the new triazoles.

Transmission of fluconazole-resistant Candida albicans between patients with AIDS and oropharyngeal candidiasis documented by pulsed-field gel electrophoresis

Electrophoretic karyotype and restriction endonuclease analysis of genomic DNA were used for the typing of nine isolates of Candida albicans from the oral cavities of two patients with AIDS--a husband and wife--whose infections became resistant to treatment with fluconazole (400 mg/d). The in vitro susceptibilities of sequential isolates to fluconazole and two other triazoles, itraconazole and the investigational drug D0870, were also evaluated. DNA analysis showed that the isolates responsible for fluconazole-resistant episodes of oropharyngeal candidiasis in the two patients were genetically related. In vitro susceptibility to fluconazole correlated well with clinical outcome. Although the minimal inhibitory concentrations of itraconazole and D0870 for fluconazole-resistant isolates were higher than those for fluconazole-susceptible isolates, both of the former triazoles exhibited good in vitro activity against the isolates tested.

In vitro evaluation of combination of fluconazole and flucytosine against Cryptococcus neoformans var. neoformans

Amphotericin B and fluconazole are current acceptable therapies for cryptococcal meningitis; however, their effect remains suboptimal. The combination of fluconazole and flucytosine has yielded encouraging clinical results in human immunodeficiency virus patients with cryptococcal meningitis. To investigate the biological basis of this finding, we performed in vitro combination testing of fluconazole and flucytosine against 50 clinical strains of Cryptococcus neoformans var. neoformans. Synergy (fractional inhibitory concentration index of < 1.0) was observed in 62% of cases, while antagonism (fractional inhibitory concentration index of > 2.0) was not observed. For cases in which synergy was not achieved (autonomous or additive effects), the beneficial effect of the combination was still seen (i.e., there was still a decrease, although not as dramatic, in the MIC of one or both drugs when used in combination). The in vitro inhibitory action of flucytosine was greatly enhanced by the addition of fluconazole; the flucytosine MICs for Cryptococcus isolates were markedly decreased to concentrations which were severalfold lower than the achievable cerebrospinal fluid flucytosine concentration. On the other hand, the addition of flucytosine did not greatly enhance the in vitro activity of fluconazole if the initial fluconazole MIC for the isolate was > or = 8 micrograms/ml. Controlled clinical studies are warranted to further elucidate the potential utility of fluconazole-flucytosine combination therapy.

Evaluation of the E test system versus a microtitre broth method for antifungal susceptibility testing of yeasts against fluconazole and itraconazole

The E test strip (AB Biodisk, Solna, Sweden) as an antimicrobial susceptibility testing method is a new and promising tool with broad application in microbiology. This method is less labour intensive than broth dilution methods and may be useful for testing individual clinical isolates. In contrast to several publications comparing E test antibacterial strips with NCCLS reference methods, there is little information about the performance of E test antifungal strips. This study compared fluconazole and itraconazole MICs obtained by E test with a microbroth dilution method performed to NCCLS guidelines. Fluconazole and itraconazole E test results exhibited good correlation with the broth microdilution (82% and 81% agreement within +/- 1 two-fold dilution, respectively). The E test is easy to perform and generates MICs for Candida species in 24 h.

Comparison of Etest and National Committee for Clinical Laboratory Standards broth macrodilution method for azole antifungal susceptibility testing

The use of Etest strips for antimicrobial susceptibility testing is a new and promising method with broad applications in microbiology. Since these strips contain a predefined continuous gradient of a drug, it is possible to obtain a reproducible, quantitative MIC reading. We performed a prospective and double-blinded study to compare the Etest and National Committee for Clinical Laboratory Standards (Villanova, Pa.) broth macrodilution methods for determining the MICs of fluconazole, itraconazole, and ketoconazole for 100 clinical isolates (25 Candida albicans, 25 Cryptococcus neoformans var. neoformans, 20 Torulopsis [Candida] glabrata, 15 Candida tropicalis, and 15 Candida parapsilosis). The Etest method was performed according to the manufacturer's instructions, and the reference method was performed according to National Committee for Clinical Laboratory Standards document M27-P guidelines. Despite differences between results for some species-drug combinations, Etest and macrobroth MICs were, in general, in good agreement. The MIC agreement rates for the two methods, within +/- 1 dilution, were 71% for ketoconazole, 80% for fluconazole, and 84% for itraconazole. According to our data, Etest has potential utility as an alternative method.

DNA subtypes and fluconazole susceptibilities of Candida albicans isolates from the oral cavities of patients with AIDS

Sixty-two Candida albicans isolates from the oral cavities of 28 patients with AIDS who were receiving fluconazole therapy were typed by restriction endonuclease analysis followed by pulsed-field gel electrophoresis; these isolates were then tested for fluconazole susceptibility by a standard broth dilution method. Sequential isolates (range, 2-4) were evaluated for 22 patients; only one isolate was evaluated for six patients. DNA subtyping revealed a total of 37 different DNA subtypes. Twelve (54.5%) of 22 patients with multiple episodes of oropharyngeal candidiasis were infected with a single DNA subtype throughout the observation period. Ten (45.5%) of 22 patients with multiple episodes of oropharyngeal candidiasis were infected with two or three DNA subtypes during the observation period. In vitro susceptibility tests revealed that MICs of fluconazole ranged from < or = 0.125 microgram/mL to 64 micrograms/mL, with an MIC50 of 0.5 microgram/mL and an MIC90 of 4 micrograms/mL. A significant increase in the MICs (fourfold or greater) of fluconazole for sequential C. albicans isolates was found for 66.6% of the patients infected with a single DNA subtype and for 50% of the patients infected with multiple DNA subtypes. Despite a limited number of patients and isolates, our data suggest that C. albicans isolates that are susceptible to fluconazole at MICs of > or = 8 micrograms/mL in vitro will be less susceptible in vivo to standard doses (100-200 mg/d) of this drug.

Turbidimetric and visual criteria for in vitro susceptibility testing of Cryptococcus neoformans clinical isolates

The drug concentration which inhibited 50% of growth (IC50), the lowest drug concentration at which growth was less than 30% of that in a positive control well (IC30), the visual minimal inhibitory concentration (MIC visual), were applied to study the effects of fluconazole, itraconazole, amphotericin B and flucytosine against 27 isolates of Cryptococcus neoformans by a broth microdilution technique. When the recommendations established by NCCLS Subcommittee on Antifungal Susceptibility Test were applied for the visual reading of the microplates, the results were comparable with those obtained by the turbidimetric method. No statistically significant differences between MIC visual and IC30 readings were observed with the azoles. There were, however, differences with amphotericin B and flucytosine. In absolute terms MICs of amphotericin B and flucytosine showed higher values than IC30s and IC50s.

In vitro activity of a new antifungal triazole, D0870, against Candida albicans isolates from oral cavities of patients infected with human immunodeficiency virus

We investigated the in vitro activity of a new antifungal triazole, D0870, against 100 Candida albicans isolates from the oral cavities of patients infected with human immunodeficiency virus by using a broth macrodilution method following the recommendations provided by the National Committee for Clinical Laboratory Standards (document M27-P). All of the isolates were chosen from C. albicans isolates already tested for fluconazole susceptibility by the procedure of the National Committee for Clinical Laboratory Standards. Fifty isolates were considered fluconazole susceptible (MICs, < or = 4 micrograms/ml), and 50 isolates were considered fluconazole resistant (MICs, > or = 8 micrograms/ml). The in vitro data demonstrated that D0870 had good activity against isolates tested; for 90% of all strains of C. albicans, MICs were 0.5 micrograms/ml. However, the D0870 MICs for the fluconazole-susceptible isolates were lower than those for the fluconazole-resistant isolates; MICs for 50 and 90% of the isolates tested were < or = 0.0078 and 0.06 micrograms/ml, respectively, for fluconazole-susceptible isolates and 0.25 and 2 micrograms/ml, respectively, for fluconazole-resistant isolates (P < 0.001). Our data suggest that this new triazole could represent a valid alternative in the treatment of oral candidiasis in human immunodeficiency virus-infected patients.

Comparative study of broth macrodilution and microdilution techniques for in vitro antifungal susceptibility testing of yeasts by using the National Committee for Clinical Laboratory Standards' proposed standard

A comparative study of broth macro- and microdilution methods for susceptibility testing of fluconazole, itraconazole, flucytosine, and amphotericin B was conducted with 273 yeasts. The clinical isolates included 100 Candida albicans, 28 Candida tropicalis, 25 Candida parapsilosis, 15 Candida lusitaniae, 15 Candida krusei, 50 Cryptococcus neoformans var. neoformans, 25 Torulopsis (Candida) glabrata, and 15 Trichosporon beigelii strains. Both methods were performed according to the National Committee for Clinical Laboratory Standards' (NCCLS) recommendations (document M27-P). For fluconazole, itraconazole, and flucytosine, the endpoint was the tube that showed 80% growth inhibition compared with the growth control for the macrodilution method and the well with slightly hazy turbidity (score 1) compared with the growth control for the microdilution method. For amphotericin B, the endpoint was the tube and/or well in which there was absence of growth. For the reference macrodilution method, the MICs were determined after 48 h of incubation for Candida spp., T. glabrata, and T. beigelii and after 72 h for C. neoformans var. neoformans. For the microdilution method, either the first-day MICs (24 h for all isolates other than C. neoformans and 48 h for C. neoformans var. neoformans) or the second-day MICs (48 and 72 h, respectively) were evaluated. The agreement within one doubling dilution of the macrodilution reference for all drugs was higher with the second-day MICs than with the first-day MICs for the microdilution test for most of the tested strains. General agreement was 92% for fluconazole, 85.7% for itraconazole, 98.3% for flucytosine, and 96.4% for amphotericin B. For C. neoformans var. neoformans and T. beigelii, the agreement of the first-day reading was higher than that of the second-day reading for fluconazole (94 versus 92%, respectively, for C. neoformans var. neoformans, and 86.7 versus 80%, respectively, for T. beigelii). Our studies indicate that the microdilution technique performed following the NCCLS guidelines with a second-day reading is a valid alternative method for testing fluconazole, itraconazole, flucytosine, and amphotericin B against these eight species of yeasts.

In vitro activity of itraconazole against fluconazole-susceptible and -resistant Candida albicans isolates from oral cavities of patients infected with human immunodeficiency virus

A broth macrodilution technique, which was performed by following the recommendations provided by the National Committee for Clinical Laboratory Standards (document M27-P), was applied to study the in vitro activity of itraconazole against fluconazole-susceptible and -resistant Candida albicans isolates from the oral cavities of 100 patients infected with human immunodeficiency virus. The in vitro data demonstrated that itraconazole had good activity against the tested isolates; for 90% of all strains of C. albicans, MICs were 1 microgram/ml, and only one isolate was highly resistant to this triazole (MIC, > 16 micrograms/ml). However, the itraconazole MICs for the fluconazole-susceptible isolates were significantly lower than those for the fluconazole-resistant isolates; the MICs for 50 and 90% of the isolates tested were < or = 0.03 and 0.25 microgram/ml, respectively, for the fluconazole-susceptible isolates and 0.5 and 1 microgram/ml, respectively, for the fluconazole-resistant isolates (P = 0.00001). Our findings could be of clinical relevance because human immunodeficiency virus-infected patients who fail fluconazole therapy for oral and/or esophageal candidiasis may require itraconazole at doses higher than those used in standard therapy.

Comparison of broth dilution and semisolid agar dilution for in vitro susceptibility testing of Cryptococcus neoformans

We compared the in vitro activity of amphotericin B, flucytosine, itraconazole, fluconazole, ketoconazole and miconazole against 18 strains of Cryptococcus neoformans by using two methods: microbroth dilution and semisolid agar dilution. By both of the methods minimum inhibitory concentrations (MICs) showed a wide range for all antifungal agents but not for amphotericin B. Statistically significant differences between the two methods were observed only with amphotericin B and flucytosine, p = 0.048 and p = 0.045 respectively. Our study suggests that azole susceptibility testing for C. neoformans may be performed by the broth microdilution as well as the semisolid agar test. The choice of the method when testing amphotericin B and flucytosine is more problematic.

Turbidimetric and visual criteria for determining the in vitro activity of six antifungal agents against Candida spp. and Cryptococcus neoformans

The drug concentration which inhibited 50% of growth (IC50), the lowest drug concentration at which growth was less than 30% of that in a positive control well (IC30), the visual minimal inhibitory concentration (MIC), and the minimum fungicidal concentration (MFC), were applied to study the effects of fluconazole, itraconazole, ketoconazole, miconazole, flucytosine, and amphotericin B against 36 isolates of Candida spp. and Cryptococcus neoformans by a broth microdilution technique. When the recommendations established by the NCCLS Subcommittee on Antifungal Susceptibility Tests were applied for the visual reading of the microplates, the results were comparable with those obtained by the turbidimetric methods. Differences between MICs and IC30s were observed with miconazole against strains of C. glabrata (p = 0.014) and with flucytosine against strains of C. neoformans (p = 0.041). Differences between MICs and IC50s were observed with fluconazole against strains of C. albicans (p = 0.027), C. tropicalis (p = 0.046), and C. neoformans (p = 0.041); with miconazole against strains of C. glabrata (p = 0.014); and with amphotericin B against strains of C. parapsilosis (p = 0.025). Ten additional isolates of C. albicans from AIDS patients suffering from recurrent episodes of oral candidiasis and clinically resistant to fluconazole also were included in this study. The MICs of fluconazole of these strains were significantly higher than those of the control group (p = 0.003). When the turbidimetric parameters were applied for testing the in vitro activity of fluconazole against the above isolates, both IC30 and IC50 were capable of discriminating the strains of the two groups (p = 0.002, p = 0.001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Fluconazole and ketoconazole in the treatment of oral and esophageal candidiasis in AIDS patients

In our study 77 AIDS patients suffering from oral and/or esophageal candidiasis were evaluated: 38 received fluconazole, 39 ketoconazole. We analyzed the rates of clinical and mycological responses, relapses and toxicities. In vitro susceptibility tests for both antifungal drugs were performed by evaluating their Minimal Inhibitory Concentrations (MICs). The azole drugs investigated show a good activity in the treatment of oropharyngeal and esophageal candidiasis also in advanced stages of HIV infection. Clinical cure or improvement were achieved in 29 (76.3%) and 31 (79.4%) of the patients treated with fluconazole or ketoconazole respectively. Clinical or laboratory adverse experiences related to fluconazole were seen in 7 (21.2%) patients while ketoconazole provoked adverse experiences in 9 (26.4%) patients. In vitro susceptibility tests, if repeated more than once, both in primary infection and relapses, could be important to demonstrate a probable sensitivity change or resistance of the tested strains.

Fluconazole, itraconazole and ketoconazole in-vitro activity. A comparative study

We compared in-vitro activity of fluconazole, itraconazole and ketoconazole by evaluating their Minimal Inhibitory Concentrations (MICs) for 100 fungal strains isolated from different biological specimens of ARC/AIDS patients. A semisolid agar medium was used: this method is suitable for testing molds and yeasts, and can be applied to all azole antifungal drugs. Fluconazole had higher MICs than two other tested drugs, especially for Candida krusei strains; however it never had a MIC higher than 40 mg/l. Itraconazole and ketoconazole had MICs higher than 40mg/l for one Cryptococcus neoformans strain. There were no significant differences for itraconazole and ketoconazole among the tested strains.