In vitro susceptibility of yeasts for fluconazole and itraconazole. Evaluation of a microdilution test

In vitro susceptibilities were determined for a total of 159 clinical isolates and 12 reference strains of yeasts belonging to different Candida species including 94 Candida albicans strains, and further genera such as Cryptococcus, Trichosporon, Geotrichum and Saccharomyces. Minimum inhibitory concentration (MIC) values for fluconazole and itraconazole were assessed using a microdilution technique with the semisynthetic high resolution (HR) medium supplemented with glucose and asparagine but without sodium hydrogen carbonate (pH 7.0), according to a proposal of the working group 'Clinical Mycology' of the German Speaking Mycological Society. Fluconazole MIC values for C. albicans were between 0.125 and > or = 128 micrograms ml-1. Thus, the median of 1 microgram ml-1 showed that the overall fluconazole susceptibility was good. As expected, Candida krusei (seven strains) exhibited diminished in vitro susceptibility with MIC values for fluconazole of 8 to 128 micrograms ml-1 with a median of 64 micrograms ml-1. Some Candida kefyr strains seemed to be less susceptible against fluconazole which was indicated by a MIC90 of 64 micrograms ml-1. Surprisingly, no Candida glabrata isolate exhibited a MIC value greater than 16 micrograms ml-1. Other Candida species, Trichosporon cutaneum, Geotrichum candidum and Saccharomyces cerevisiae showed low MICs to fluconazole. In vitro susceptibility testing of itraconazole revealed that all Candida species except C. albicans, but also Trichosporon cutaneum, Geotrichum candidum, and Saccharomyces cerevisiae exhibited acceptable low MIC values against itraconazole (0.03-2 micrograms ml-1). Their MIC90 values for itraconazole were in the close range between 0.125 and 2 micrograms ml-1. MIC values between 0.125 and 2 micrograms ml-1 were obtained, even for C. krusei strains. On the other hand, the range of C. albicans MICs was between 0.0125 and > or = 16 micrograms ml-1 with MIC50 and MIC90 values of 0.125 and > or = 16 micrograms ml-1, respectively, indicating that a considerable number of yeast strains have high MICs. The comparative evaluation of different experimental conditions revealed that there exists a marked influence both of inoculum size and incubation time on the results of susceptibility testing. Therefore, for routine usage 10(2) CFU ml-1 and 18-24 h incubation time for this microdilution method with HR medium are recommended.     

In vitro activity of rilopirox against fluconazole-susceptible and fluconazole-resistant Candida isolates from patients with HIV infection

The in vitro antifungal activity of the new hydroxypyridone antimycotic rilopirox has been evaluated against 38 fluconazole-susceptible and -resistant clinical isolates of Candida albicans together with other Candida species isolated from patients with human immunodeficiency virus (HIV) infection and oropharyngeal candidosis. Minimum inhibitory concentrations (MICs) of both rilopirox and fluconazole were measured by a microdilution method using high-resolution medium supplemented with asparagine and glucose at pH 7.0. In comparison, an agar dilution technique was carried out for susceptibility testing of the antifungal agents. Rilopirox was found to be able to inhibit growth of all clinical yeast isolates. The rilopirox MICs at which 50% and 90% of strains were inhibited (MIC50 and MIC90 respectively), as determined by the microdilution method, were 4 and 8 micrograms ml-1 respectively. The highest MIC values for rilopirox using microdilution and the agar dilution method were 32 or 25 micrograms ml-1 respectively. On the other hand, for fluconazole, the MIC50 and MIC90 achieved were 0.5 and 128 micrograms ml-1, respectively, which means that the MIC90 value of fluconazole was 16-fold higher than that of rilopirox. Using the agar dilution technique, the MIC values of rilopirox were in the range 0.006-25 micrograms ml-1 with a median of 3.12 micrograms ml-1. For fluconazole, the MIC90 value was four-fold higher than that for rilopirox, indicating a considerable proportion of yeast strains with high MICs of 100 micrograms ml-1, suggesting in vitro resistance to this azole antifungal. All strains with diminished fluconazole susceptibility were susceptible to rilopirox. Even Candida krusei and Candida glabrata exhibited good in vitro susceptibility to rilopirox. Therefore, this new antifungal agent may be used as an alternative not only in the treatment of vaginal candidosis, but also in oropharyngeal Candida infections, e.g. in AIDS patients.     

Vergleich von drei Antimykotika-Empfindlichkeitsprüfungs-Methoden für die In-vitro-Testung von Candida-Isolaten von Patienten mit HIV-Infektion

Zusammenfassung. Es wurden die MHK-Werte für Fluconazol von 90 Candida -Isolaten (56 C. albicans , 15 C. glabrata , 9 C. krusei und 10 C. tropicalis ) untersucht. Zur Antimykotika-Resistenztestung wurden die Mikrodilutionsmethoden nach dem Protokoll M27-P des NCCLS (M27-Pmicro) mit RPMI 1640-Medium sowie der Methode nach Troke & Pye mit HR-Medium (HRmicro) als auch die Agardiffusionsmethode mit dem Etest (YNB-Agar) verwendet. Die Ergebnisse mit diesen Methoden wurden mit den klinischen Befunden verglichen. Sämtliche C. albicans -Isolate von AIDS-Patienten mit Fluconazol-refraktärer Candidose hatten MHK-Werte entweder ≥ 6,25 μg/ml (M27-Pmicro) oder ≥ 25 μg/ml (HRmicro und Etest). Andererseits lagen die MHK-Werte von C. albicans -Isolaten bei AIDS-Patienten mit Fluconazol-empfindlicher Candidose teil-weise ebenfalls über diesen Endpunkten. Ein mögliches Ansprechen auf eine Fluconazol-Therapie kann somit nicht zwangsläufig von dem MHK-Wert abgeleitet werden.
Summary. The MIC values of fluconazole were determined for 96 Candida isolates (56 C. albicans , 15 C. glabrata , 9 C. krusei and 10 C. tropicalis ). The methods employed for antifungal susceptibility testing were: microdilution according to the protocol M27-P of the NCCLS (M 27-Pmicro) using RPMI 1640 medium or HR medium following Troke & Pye (HRmicro) as well as the agar diffusion method by means of the Etest (YNB agar). The in vitro results were compared with the clinical outcome of patients. All C. albicans isolates received from AIDS patients with fluconazole-refractory candidosis showed MICs of ≥ 6,25 mg/ml (M27-Pmicro) or ≥ 25 mg/ml (MRmicro) and Etest). On the other hand some MICs of C. albicans isolates from AIDS patients with fluconazole-sensitive candidosis were also beyond these breakpoints. Therefore a possible success of a fluconazole therapy cannot unequivocally be predicted from the MIC value determined in vitro.     

Fluconazole and itraconazole susceptibilities of Candida spp. isolated from oropharyngeal specimens and blood cultures of paediatric haematology/oncology patients

This study examined the in vitro susceptibilities to fluconazole and itraconazole of isolates of Candida spp. from surveillance oropharyngeal specimens and blood cultures from paediatric patients with malignancy. The species distribution of 100 isolates from oropharyngeal specimens was C. albicans 86%, C. glabrata 7%, C. lusitaniae 4%, C. parapsilosis 2% and C. tropicalis 1%. From a total of nine isolates from blood cultures the species distribution was C. albicans 33.3%, C. parapsilosis 33.3 % and C. guilliermondii 33.3%. Only three of the oropharyngeal isolates were resistant to fluconazole (MIC > or = 64 mg l(-1)) and only two were resistant to itraconazole (MIC > or = 1 mg l(-1)). None of the blood culture isolates was resistant to either agent. At this centre, C. albicans is the predominant species from oropharyngeal specimens, but non-albicans Candida species predominate in blood cultures. Although resistance to fluconazole and itraconazole is rare at present, continued surveillance is warranted to monitor trends in species distribution and antifungal susceptibility.     

Phenotypic variation and antifungal susceptibility patterns of Candida albicans strains isolated from neutropenic patients

The aim of this study was to investigate the relationship between phenotypes of Candida albicans strains isolated from clinical specimens and the susceptibility of the strains to three antifungal agents, fluconazole, amphotericin B and flucytosine. Oropharyngeal, gastrointestinal and urogenital tract specimens were collected from 122 neutropenic patients who had received no previous prophylactic treatment. Each of 122 C. albicans strains recovered was found to express one of the six phenotypes: smooth, fuzzy, irregular, star, ring and stipple. The mean minimum inhibitory concentrations (MICs) of fluconazole was consistently higher for C. albicans strains expressing the stipple phenotype. The mean MICs for the six phenotypes of C. albicans strains ranged between 1.22 and 7.94 micrograms ml-1 for fluconazole, 0.99 and 2.55 micrograms ml-1 for amphotericin B and 1.23 and 1.83 micrograms ml-1 for flucytosine. The antifungal susceptibility of the stipple phenotype requires attention, especially in patients who are clinically unresponsive to fluconazole chemotherapy or in cases of life-threatening C. albicans infections of immunocompromised hosts. Long-term use of fluconazole may explain the outcome of the resistant stipple phenotype.     

Posaconazole susceptibility testing against Candida species: comparison of broth microdilution and E-test methods

Posaconazole (POS) is a newer triazole with activity against yeasts and moulds. POS and fluconazole were tested in vitro against 32 Candida albicans, 30 C. glabrata, 21 C. tropicalis, 29 C. krusei, 28 C. parapsilosis, 50 C. inconspicua, 13 C. kefyr and 5 C. famata isolates using CLSI broth microdilution method (BMD). We compared E-test and a modified BMD using polyethylene-glycol (PEG) as solvent to the CLSI method. BMDs and E-test were performed according to CLSI and the manufacturer's instructions respectively. Geometric means of POS MICs using BMD were 0.71, 0.22 and 0.21 microg ml(-1) against C. glabrata, C. krusei and C. inconspicua, respectively, and remained below 0.1 microg ml(-1) against all other species tested. One of two C. albicans and two of three C. glabrata isolates resistant to fluconazole showed MICs above 8 microg ml(-1) to POS. The impact of using PEG instead of DMSO had only a minor effect (agreements above 95% with the exception of C. parapsilosis). E-tests read after 24 h showed good agreement with the BMD. POS exhibited excellent in vitro activity against Hungarian Candida strains. E-test showed good correlation with the CLSI method, but to facilitate the comparability of results we believe that DMSO should be used as solvent in the BMD.     

Molecular epidemiology of Candida species isolated from urine at an intensive care unit

Candida spp. has been the leading microorganism isolated from the urine specimens of patients hospitalized at the Anesthesiology and Reanimation intensive care unit (ICU) of Dokuz Eylul University Hospital, Izmir, since 1998. This study was undertaken to investigate the clonal relationship of Candida urine isolates in order to find the mode of spread among the patients. Epidemiological surveillance of 38 Candida albicans, 15 Candida tropicalis and 12 Candida glabrata recovered from the urine specimens of patients who were hospitalized in the ICU between June 11, 2000 and October 15, 2001 was carried out by antifungal susceptibility testing and randomly amplified polymorphic DNA (RAPD) analysis. Two short primers [Cnd3 (5'-CCAGATGCAC-3') and Cnd4 (5'-ACGGTACACT-3')] were used for RAPD. None of the isolates had high minimal inhibitory concentration (MIC) values (>1 microg ml(-1)) against amphotericin B with MIC50 values of 0.5 microg ml(-1), 0.5 microg ml(-1) and 0.125 microg ml(-1) for C. albicans, C. tropicalis and C. glabrata isolates, respectively. However, three C. glabrata isolates were resistant and one C. albicans and five C. glabrata isolates were dose-dependent susceptible (D-DS) to fluconazole. Among C. albicans isolates 19 and 20 patterns were detected with primers Cnd3 and Cnd4, respectively. When primers Cnd3 and Cnd4 were evaluated together, three and four genotypes were identified for C. tropicalis and C. glabrata isolates, respectively. Our results suggest that the source of C. albicans isolates was mostly endogenous. It is difficult to interpret the mode of spread of C. tropicalis and C. glabrata urine isolates as we obtained insufficient banding patterns for these species.     

In vitro susceptibility of 545 isolates of Candida spp. to four antifungal agents

Summary. The in vitro susceptibility to amphotericin B, fluconazole, itraconazole and ketoconazole of 545 Candida strains from patients treated at the University Hospital of the Canaries was determined by means of a microdilution test. The distribution of the species was as follows: Candida albicans (342), Candida tropicalis (70), Candida glabrata (68), Candida parapsilosis (65). Of Candida albicans isolates, 8.5% and 7.6% showed resistance to itraconazole and fluconazole respectively. Of C. tropicalis isolates 34.3%, 27.1% and 2.9% were resistant to itraconazole, fluconazole and ketaconazole respectively. For C. glabrata , 10.3% and 4.4% of the isolates under study demonstrated resistance to fluconazole and itraconazole respectively. Only 4.6% and 1.5% of C. parapsilosis isolates demonstrated resistance to fluconazole and itraconazole respectively. C. tropicalis was the most resistant strain and C. parapsilosis the most sensitive. The greatest percentages of resistance in vitro were seen with the triazoles.
Zusammenfassung. Es wurde die Empfindlichkeit von 545 Candida -Stämmen für Amphotericin B, Fluconazol, Itraconazol und Ketoconazol in vitro in einem Mikrodilutionstest bestimmt. Bei den Stämmen handelte es sich um Isolate von Patienten, die in der Universitäts-Klinik der Kanarischen Inseln behandelt worden waren. Das Untersuchungsgut war wie folgt verteilt: 342 Candida albicans , 70 C. tropicalis , 68 C. glabrata , 65 C. parapsilosis. Bei C. albicans waren 8.5% gegen Itraconazol und 7.6% gegen Fluconazol resistent. Bei C. tropicalis wurden 34.3% resistent gegenüber Itraconazol befundet, 27.1% gegen Fluconazol und 2.9% gegen Ketoconazol. Bei C. glabrata waren 10.3% resistent gegen Fluconazol und 4.4% gegen Itraconazol. Candida parapsilosis wurde zu 4.6% gegen Fluconazol und zu 1.5% gegen Itraconazol als resistent befundet. Somit erwies sich C. tropicalis als die resistenteste und C. parapsilosis als die sensibelste Art.     

Identification of Candida species isolated from patients in intensive care unit and in vitro susceptibility to fluconazole for a 3-year period

Species level identification of Candida and antifungal susceptibility testing is not generally performed in routine laboratory practice. There is limited information about the distribution of Candida species and antifungal susceptibility in Turkey. In this study, we aimed at identifying Candida isolates to species level from various samples obtained from patients treated in an intensive care unit between 2002 and 2005 and to evaluate fluconazole susceptibilities of the isolates. A total of 320 Candida isolates obtained from 270 patients were identified by conventional methods and using API (Candida and/or 20C AUX) system. Antifungal susceptibility testing was performed by broth microdilution method. Candida albicans was isolated with the highest frequency (65.6%) followed by C. parapsilosis (11.3%), C. glabrata (8.8%) and C. tropicalis (7.8%). Of all the isolates, 92.9% revealed susceptibility to fluconazole. Susceptibility to fluconazole was highest for C. albicans followed by C. parapsilosis and C. glabrata. The MIC(90) values for C. albicans, C. parapsilosis, C. glabrata and C. tropicalis were 1, 2, 8 and 4 mug ml(-1) respectively. Fluconazole remains effective against both C. albicans and the majority of non-albicans Candida species. In this study, we determine the distribution of Candida species and evaluate the susceptibilities of the isolates, particularly for the azoles.     

In vitro comparative evaluations of the postantifungal effect: synergistic interaction between flucytosine and fluconazole against Candida albicans

In vitro comparative evaluations were performed to study the efficacy of combinations of flucytosine and fluconazole in producing a postantifungal effect (PAFE) on Candida albicans. Initial studies were done to determine MIC, FIC (fractional inhibitory concentration) and optimal PAFE parameters. A turbidometric method was used to measure yeast cell growth following exposure to different concentrations of the two drugs for periods of 0.5, 1 or 2 h at temperatures of 30 degrees C and 37 degrees C. The PAFE was determined by the difference in time (h) required for growth of the control and test cultures to reach the 0.5 absorbance level following removal of the drug by dilution. Ten strains of C. albicans were then assayed (30 degrees C; 2 h exposure time) and a synergistic PAFE was evidenced with the two drugs at concentrations well below their individual MICs. PAFEs ranging from 3.8 to 10.5 h, which persisted for 1.2-2.5 h longer than those achieved with either agent separately, were evidenced when flucytosine and fluconazole were combined (flucytosine: fluconazole ratios of 1:16-1:32) at concentrations ranging from 0.024 to 0.098 micrograms ml-1 and 0.78 to 1.56 micrograms ml-1 respectively. The concentrations of each agent required to produce an optimal PAFE varied according to the C. albicans strain being assayed.     

Phospholipase and protease activities in clinical Candida isolates with reference to the sources of strains

The present study was aimed at determining in vitro phospholipase and protease activities in 95 clinical isolates of various Candida species (C. albicans, C. glabrata, C. guilliermondii,C.kefyr, C. krusei, C. lipolytica, C. lusitaniae, C. parapsilosis, C.rugosa and C. tropicalis). 59 (62.1%) of isolates examined were phospholipase positive and 75 (78.9.9%) were protease positive. 56 (93.3%) of C.albicans isolates tested were phospholipase producers - however only a few strains of C. glabrata and C. kefyr behaved in the same way. Protease activity was detected in 57 (95%) of C. albicans strains tested and in a few strains of C. kefyr, C.lipolytica, C. parapsilosis and C. tropicalis- the remaining isolates were negative. 56 strains of C.albicans and 2 strains of C. kefyr tested produced both phospholipase and protease.     

In Vitro Antifungal Activity of Saperconazole (R 66905) Against Candida and Torulopsis Die antimyzetische Aktivität von Saperconazol (R 66905) in vitro gegen Candida und Torulopsis

The susceptibility of several strains of Candida and Torulopsis to saperconazole, a new triazole antifungal compound, was compared to that of ketoconazole. The MICs of the two antifungal agents were determined against 70 strains of Candida albicans, 10 strains of C. guilliermondii, 10 strains of C. krusei, 10 strains of C. parapsilosis, 10 strains of C. pseudotropicalis, 10 strains of C. tropicalis and 15 strains of Torulopsis glabrata. The fungistatic activity was evaluated by the agar dilution method using BHI and casitone media after incubation for 48 hours at 28-30 degrees C. The in vitro activity of saperconazole was similar to that of ketoconazole for most of the Candida spp. tested except for C. krusei in particular. An MIC of less than or equal to 3.12 micrograms/ml for saperconazole was found with 92% of the C. albicans strains tested. In contrast, T. glabrata was more susceptible to ketoconazole.     

Emergence of Candida tropicalis as the major cause of fungaemia in India.

The fungal isolates (n = 191) from 1970 consecutive blood cultures over a 9-year period were identified. Candida tropicalis was the predominant isolate accounting for 66% of all isolates whereas Candida albicans ranked only a distant second with 21%. The difference was highly significant (P < 0.00001) The other isolates included C. parapsilosis (5.8%), C. glabrata (2.1%), C. pelliculosa (1.2%), C. lipolytica (1.0%) C. krusei (1.0%) and Trichosporon beigelii (2.6%). The isolates were obtained predominantly from postoperative patients on therapy with more than one antibiotic.     

Evaluation of the "Yeast-IDENT System" for the Identification of Medically Important Yeasts./Bewertung des "Yeast-IDENT-Systems" zur Identifizierung medizinisch wichtiger Hefen

Summary: Ninety-one coded cultures belonging to nine genera of medically important yeasts were used to evaluate the newly marketed “Yeast-IDENT” (Y-I) system for identification. The results were compared with conventional procedures which included microscopic morphology, carbohydrate assimilation and fermentation tests, other nutritional tests, and/or API 20C. The Y-I system identified isolates of Candida albicans, C. guilliermondii, C. lusitaniae, C. pseudotropicalis, Cryptococcus albidus, Cr. neoformans, Rhodotorula rubra, Saccharomyces cerevisiae, Sporobolomyces salmonicolor, Torulopsis candida and T. glabrata with 100% accuracy. With the Y-I system, other species identified with variable degree of accuracy (50–89%) included C. krusei, C. parapsilosis, C. rugosa, C. tropicalis, Cr. laurentii, Hansenula anomala and Trichosporon beigelii. One isolate each of Cr. luteolus, Cr. terreus and Prototheca wickerhamii (an achlorophyllous alga) were not identified with the Y-I system. Overall accuracy of the Y-I system was 87.2% when compared with the conventional and/or API 20C. The Y-I system is rapid and requires only 4h of incubation at 35–37°C compared with 72h to 14 d necessary for the other two procedures. Zusammenfassung: Einundneunzig verschlüsselte Kulturen von neun Genera medizinisch wichtiger Hefen wurden zur Bewertung eines neuen »Yeast-IDENT«-(Y-I)-Systems für die Hefeidentifizierung verwendet. Die Resultate wurden mit konventionellen Methoden unter Einschluß der mikroskopischen Morphologie, der Kohlenhydratassimilation und -fermentation sowie anderer Verwertungsteste und/oder mit dem API 20 C-System verglichen. Das Y-I-System identifizierte Isolate von Candida albicans, C. guilliermondii, C. lusitaniae, C. pseudotropicalis, Cryptococcus albidus, Cr. neoformans, Rhodotorula rubra, Saccharomyces cerevisiae, Sporobolomyces salmonicolor, Torulopsis candida und T. glabrata mit 100%iger Genauigkeit. Andere Hefearten wurden mit dem Y-I-System in unterschiedlichem Ausmaß (50–80%) erkannt, darunter C. krusei, C. parapsilosis, C. rugosa, C. tropicalis, Cr. laurentii, Hansenula anomala und Trichosporon beigelii. Je ein Isolat von Cr. luteolus, Cr. terreus und Prototheca wickerhamii (einer chlorophyllfreien Alge) wurden mit dem Y-I-System nicht identifiziert. Die Gesamtgenauigkeit des Y-I-Systems lag bei 87,2%, verglichen mit den konventionellen Methoden und/oder API 20 C. Das Y-I-System ist schnell und erfordert nur 4 h Bebrütungsdauer bei 35–37°C im Vergleich zu 72 h bis 14 d, die bei den beiden anderen Methodiken benötigt werden.     

In vitro susceptibilities of cerebrospinal fluid isolates of Cryptococcus neoformans collected during a ten-year period against fluconazole,voriconazole and posaconazole (SCH56592)

We investigated the in vitro susceptibilities of 213 cerebrospinal fluid isolates of Cryptococcus neoformans isolated from 192 patients through a 10-year period, 1990-99, against fluconazole, voriconazole and posaconazole (SCH56592) by using the NCCLS (National Committee for Clinical Laboratory Standards) macrodilution method, M27-A. The overall MICs50 and MICs90 of fluconazole, voriconazole and posaconazole were found to be 2 and 8 micro g ml-1, 相似文献   

Comparative evaluation of Candi Select test and conventional methods for identification of Candida albicans in routine clinical isolates

The Candi Select test (Sanofi Diagnostics, Pasteur, Marnes-La-Coquette, France) is a new yeast-selective medium for the identification of Candida albicans in the clinical laboratory. The performance of this test was compared with the conventional methods of chlamydospore formation, germ tube formation and carbohydrate fermentation. Four hundred and twenty clinical yeast isolates from 412 fresh clinical specimens, including 283 C. albicans, 59 C. tropicalis, 39 Trichosporon spp., 19 C. glabrata, 11 Cryptococcus neoformans and 9 other yeasts, were evaluated. Colonies of C. albicans produced a blue-green colour on the Candi Select media which could be distinguished from the other yeasts with the naked eye within 24-48 h. The sensitivity and specificity of the Candi Select test for the identification of C. albicans were 99.65% and 97.08%, respectively. The blue-green colonies of C. albicans were easy to identify and recognize in mixed cultures and did not need detailed microscopic examination.     

A head-on comparison of the in vitro antifungal activity of conventional and lipid-based amphotericin B: a multicenter study

A comparative study of conventional amphotericin B, Abelcet and AmBisome was performed using a microdilution format of the NCCLS M27-A methodology for susceptibility testing against 300 fungal isolates (152 yeasts, 148 filamentous fungi) in both RPMI-1640 and antibiotic medium #3 (AB3). The clinical isolates included Candida albicans (n=54), Candida glabrata (n=25), Candida parapsilosis (n=23), Candida krusei (n=19), Candida lusitaniae (n=14), Cryptococcus neoformans (n=5), Candida tropicalis (n=12), Aspergillus flavus (n=34), Aspergillus fumigatus (n=46) and 68 other filamentous fungi encompassing 22 different genera. The minimal inhibitory concentrations (MIC) for all drugs were defined as the lowest concentrations in which there was no visible growth. MICs were determined after 48 h for yeasts and 72 h for filamentous fungi. The mean MICs +/- standard error (microg/ml) for yeasts and filamentous fungi, respectively, were: Abelcet, 0.51+/-0.21, 4.34+/-0.61; AmBisome, 1.28+/-0.24, 5.68+/-0.57; amphotericin B, 0.29+/-0.11, 1.12+/-0.19, respectively. Overall, against both yeasts and filamentous fungi Abelcet proved to have more potent antifungal activity than AmBisome. Using AB3 as opposed to RPMI-1640 generally produced lower MIC values but did not have any effect on the order of relative activity with all of the antifungal agents tested. In conclusion, our data shows that Abelcet is more active than AmBisome against pathogenic yeast and filamentous fungi when assayed in AB3 in vitro. Comparison of the activities of these antifungals in experimental animal models is necessary to determine whether these in vitro findings are correlated with in vivo efficacy.     

Adherence of Candida strains isolated from the human gastrointestinal tract

The adherence of different Candida strains isolated from the human gastrointestinal tract was studied. The 23 Candida strains isolated from faeces were C. albicans (12), C. glabrata (2), C. krusei (2), C. parapsilosis (2), C. tropicalis (2), C. colliculosa (1), C. kefyr (1) and C. lusitaniae (1). Buccal epithelial cells from different healthy donors were used. Adherence values were maximal for C. albicans and minimal for C. krusei. A relation exists between yeast adherence capacity and the ability to colonize mucosal surfaces.     

Susceptibility of Candida Species to Cilofungin (LY-121019)

The antifungal activity of a new semi-synthetic lipopeptide named cilofungin (LY-121019) was studied in vitro on 102 strains of Candida and Torulopsis glabrata. A standardized protocol for susceptibility testing by means of a microtiter Sabouraud broth dilution was used. The minimal inhibitory concentrations of cilofungin for C. albicans (N = 50) ranged from 0.039 to 5.0 micrograms/ml with a geometric mean of 0.47 micrograms/ml. The same results were obtained with C. tropicalis but one strain showed higher resistance (40 micrograms/ml) suggesting an Eagle effect. The MIC for T. glabrata ranged from 5.0-40.0 micrograms/ml. C. parapsilosis and C. krusei were less susceptible (5.0-40.0 micrograms/ml). These results indicate that cilofungin exhibits a potent inhibitory action on C. albicans and C. tropicalis. This effect was lower against the other species of Candida and T. glabrata studied.