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Candida nivariensis and Candida bracarensis were isolated from patients with vulvovaginal candidiasis (VVC). Candida nivariensis and Candida bracarensis were found in presumptive Candida glabrata isolates, which were identified using the API Candida system. We retrospectively re-examined vaginal presumptive Candida glabrata isolates for Candida nivariensis and Candida bracarensis from January 1, 2003, through December 31, 2012, via detection of the ITS1 region and the 5.8S ribosomal RNA gene. Among 301 presumptive Candida glabrata isolates, 293 isolates were confirmed as C. glabrata (97.34 %), 7 isolates were identified as C. nivariensis (2.33 %) and 1 isolate was identified as C. bracarensis (0.33 %). The C. nivariensis and C. bracarensis isolates were confirmed by sequencing. All C. nivariensis isolates were susceptible to nystatin and susceptible or susceptible dose-dependent to fluconazole, itraconazole, miconazole, and clotrimazole. The C. bracarensis isolate was susceptible to nystatin and the tested azoles. Among the seven patients with VVC caused by C. nivariensis and who were treated with various antifungal agents, only one patient achieved mycological eradication at both the day 7-14 and day 30-35 follow-ups. The C. bracarensis isolate was isolated from a symptomatic pregnant woman; additional data for this patient were unavailable. We conclude that C. nivariensis and C. bracarensis existed in the vaginal samples of patients with VVC. Therapeutic efficacy in the patients with C. nivariensis was poor and inconsistent with the observed in vitro antifungal susceptibility, which requires further study.

Malassezia pachydermatis is a yeast that is frequently involved as a secondary/perpetuating factor in canine otitis externa. Topical therapies with different antifungal agents, mainly azole compounds, are generally successful in controlling the yeast overgrowth, but treatment failure and rapid recurrences are common. This study compared the in vitro antifungal susceptibility of M. pachydermatis isolates obtained from chronic and acute cases of otitis externa. The aim was to assess the possible onset of resistance mechanisms in isolates involved in long-lasting episodes with poor response to treatment. We evaluated the in vitro susceptibility to miconazole (MCZ) and clotrimazole (CTZ) of 42 isolates of M. pachydermatis obtained from dogs with chronic (group A, n = 25) and acute otitis (group B, n = 17), using a modified CLSI M27-A3 microdilution method. All isolates were inhibited by the antifungal agents employed, but Malassezia isolates from group A were significantly associated with higher minimum inhibitory concentration (MIC) values for both agents (Median MIC values: MCZ group A 2 µg/ml, group B 1 µg/ml; CTZ group A 8 µg/ml, group B 4 µg/ml). These findings prove that these isolates had a reduced in vitro susceptibility to the antifungal agents tested. However, it is unlikely that this could have any influence on the outcome of a topical treatment. Indeed, marketed products include concentrations of the tested agents that largely exceed even the highest MICs found in this study (in most cases at least 1,000 × the MIC, or greater). In conclusion, this study suggests that isolates of M. pachydermatis involved in chronic cases of canine external otitis and exposed to repeated antifungal treatments are unlikely to develop mechanisms of resistance of clinical relevance.

Neoscytalidium dimidiatum is an opportunistic fungus causing cutaneous infections mostly, which are difficult to treat due to antifungal resistance. In Malaysia, N. dimidiatum is associated with skin and nail infections, especially in the elderly. These infections may be mistaken for dermatophyte infections due to similar clinical appearance. In this study, Neoscytalidium isolates from cutaneous specimens, identified using morphological and molecular methods (28 Neoscytalidium dimidiatum and 1 Neoscytalidium sp.), were evaluated for susceptibility towards antifungal agents using the CLSI broth microdilution (M38-A2) and Etest methods. Amphotericin B, voriconazole, miconazole and clotrimazole showed high in vitro activity against all isolates with MIC ranging from 0.0313 to 1 µg/mL. Susceptibility towards fluconazole and itraconazole was noted in up to 10% of isolates, while ketoconazole was inactive against all isolates. Clinical breakpoints for antifungal drugs are not yet available for most filamentous fungi, including Neoscytalidium species. However, the results indicate that clinical isolates of N. dimidiatum in Malaysia were sensitive towards miconazole, clotrimazole, voriconazole and amphotericin B, in vitro.

Denture stomatitis is often treated with antifungal agents but recurrences or new episodes are common, and certain episodes can be resistant. New triazoles, such as posaconazole and voriconazole, may represent useful alternatives for management. In vitro activities of amphotericin B, nystatin, miconazole, fluconazole, itraconazole, posaconazole and voriconazole against 150 oral Candida (101 C. albicans, 18 C. tropicalis, 12 C. glabrata, 11 C. guilliermondii, 4 C. parapsilosis, 2 Saccharomyces cerevisiae, 1 C. dubliniensis and 1 C. krusei) from 100 denture wearers were tested by the CLSI M27-A3 method. Resistant isolates were retested by Sensititre YeastOne and Etest. Most antifungal agents were very active. However, 4 C. glabrata (33.3%), 2 C. tropicalis (11.1%), 6 C. albicans (5.6%) and 1 C. krusei were resistant to itraconazole. Posaconazole was active against 143 yeast isolates (95.3%): 6 C. albicans (5.9%) and 1 C. tropicalis (5.6%) were resistant. Geometric mean MICs were 0.036 μg/ml for C. parapsilosis, 0.062 μg/ml for C. albicans, 0.085 μg/ml for C. tropicalis, 0.387 μg/ml for C. guilliermondii and 0.498 μg/ml for C. glabrata. Voriconazole was active against 148 isolates (98.7%) with geometric mean MICs ranging from 0.030 μg/ml for C. parapsilosis, 0.042 μg/ml for C. albicans, 0.048 μg/ml for C. tropicalis, 0.082 μg/ml for C. guilliermondii, to 0.137 μg/ml for C. glabrata. Only 2 C. albicans (2%) were resistant to voriconazole showing cross-resistance to other azoles. Posaconazole and voriconazole have excellent in vitro activities against all Candida isolates and could represent useful alternatives for recalcitrant or recurrent candidiasis.

Unlike various disinfectants, antifungals have not been commonly incorporated so far in medical devices, such as catheters or prostheses, to prevent biofilm formation by Candida spp. In the present study, five antimycotics were added to polydimethyl siloxane (PDMS) disks via admixture (nystatin) or impregnation (trimethylsilyl-nystatin (TMS-nystatin), miconazole, tea tree oil (TTO), zinc pyrithione). Nystatin-medicated PDMS disks exhibited a concentration-dependent inhibitory effect on biofilm formation in a microtiter plate (MTP) but not in a Modified Robbins Device (MRD). This observation, together with HPLC data and agar diffusion tests, indicates that a small fraction of free nystatin is released, which kills Candida albicans cells in the limited volume of a MTP well. In contrast, biofilm inhibition amounted to more than one log unit in the MRD on disks impregnated with miconazole, TTO, and zinc pyrithione. It is hypothesized that the reduction in biofilm formation by these compounds in a flow system occurs through a contact-dependent effect.

Four strains of Ochroconis gallopava from 3 out of 15 Japanese hot springs were isolated. Colonies of the hot spring isolates were uniformly floccose and dark olive green on the surface and dark brown on their reverse side on potato dextrose agar (PDA) plates, however, they became felty, flat, and brownish-black, and produced a reddish-brown pigment after several times of subculture at room temperature. Shapes and sizes of conidia of the four strains were individual, while the D1/D2 domain of the large subunit ribosomal RNA gene sequences showed 99.7% identity in the GenBank database. The DNA pattern of the hot spring isolates amplified by species specific loop mediated isothermal amplification method were as the same pattern as that of a clinical isolate. The minimum inhibitory concentrations of antifungal agents to O. gallopava isolated from the hot springs were ranged from 0.5 to 1 microg/ml in amphotericin B, 1 to 16 microg/ml in flucytosine, 0.125 to 0.25 microg/ml in itraconazole, 1 to 4 microg/ml in miconazole, 16 to 64 microg/ml in flconazole and 0.03 to 0.5 microg/ml in micafungin. The isolates had fatal outcome in experimentally infected mice intravenously with severe invasiveness to brains and kidneys. These findings suggested that O. gallopava habitats in hot springs could be one of sources for infection.

A total of 200 samples of Candida spp. that are responsible for fingernail infections were isolated in Belo Horizonte, MG, Brazil from April 2004 to May 2005. The samples were identified by routine microbiological techniques and had the following distribution: Candida parapsilosis (40.5%), C. albicans (31.5%), C. tropicalis (26%), and C. guilliermondii (2%). We performed in vitro susceptibility tests with ciclopiroxolamine, terbinafine, ketoconazole, itraconazole, and fluconazole using the CLSI (Clinical and Laboratory Standards Institute) and EUCAST (European Committee on Antibiotic Susceptibility Testing) methodologies. The percentages of agreement between the two methodologies varied from 48 to 100% (the percentage increased to more than 60% for the majority of the samples). Percentages of agreement between the methodologies lower than 60% were seen with ketoconazole (57%) and itraconazole (48%) for samples of C. albicans and with fluconazole (54%) for samples of C. tropicalis. In general, we observed higher agreement between the values of the MICs obtained with both methodologies for ciclopiroxolamine and terbinafine for all tested species. With azoles, lower percentages of agreement between the methodologies were observed for samples C. albicans and C. tropicalis.

Trichosporon species are opportunistic yeasts which can cause infections, especially in immunocompromised patients. This is a report of Trichosporon ovoides that caused subcutaneous infection in a patient with underlying ischemic heart disease. The identification of fungal isolate was confirmed by PCR sequencing of ITS and large subunit regions in rRNA gene. In vitro susceptibility study showed that the isolate was susceptible to amphotericin B, fluconazole and voriconazole, and resistant to caspofungin, anidulafungin and itraconazole. The lesion improved after treatment with oral fluconazole and topical miconazole.

Vulvovaginal candidiasis is a common mucosal infection caused by opportunistic yeasts of the Candida genus. In this study, we isolated and identified the yeast species in the vagina of patients treated in the gynecology clinic and tested in vitro activities of fluconazole and itraconazole against 227 clinical yeast isolates by the NCCLS microdilution method. C. albicans (87.6%) was the most frequently identified species followed by C. glabrata (6.2%) and C. krusei (2.2%). Almost thirteen percent of yeast strains were resistant to fluconazole and 18.5% were resistant to itraconazole. Cross-resistance analyses of C. albicans isolates revealed that fluconazole resistance and itraconazole resistance were also associated with decreased susceptibilities to other azole derivatives mainly to ketoconazole and miconazole. At the same time no cross-resistance to polyene antibiotics amphotericin B and nystatin was observed. These results support the notion that antifungal agents used to treat vaginitis may be contributing to the drug resistance problem by promoting cross-resistance to a range of clinically used antifungals.

This study aimed to determine the clinical characteristics and in vitro susceptibilities of Candida parapsilosis sensu stricto, Candida orthopsilosis and Candida metapsilosis isolates from patients with vulvovaginal candidiasis (VVC). We analysed 63 vaginal C. parapsilosis specimens. After the molecular analyses, the isolates were characterised as C. parapsilosis sensu stricto (77.8%), C. orthopsilosis (7.9%) and C. metapsilosis (14.3%). The signs and symptoms of VVC caused by C. parapsilosis sensu lato, including itching, erythema and abnormal discharge, were milder than those caused by C. albicans. None of the C. parapsilosis sensu lato isolates were resistant to fluconazole, miconazole or itraconazole. The resistance rates of C. albicans to fluconazole, itraconazole, miconazole and clotrimazole were 2.3, 1.5, 3.1 and 0.8%, respectively. Both C. parapsilosis sensu lato and C. albicans were susceptible to nystatin. The mycological eradication rate at follow-up days 7-14 and 30-35 were 77.8% (49/63) and 76.2% (48/63), respectively, when treated with various antifungal agents and regimens. We conclude that C. parapsilosis sensu stricto and the closely related species C. orthopsilosis and C. metapsilosis were present in the vaginal samples of VVC patients. The symptoms and signs of VVC caused by C. parapsilosis are milder than those caused by C. albicans. The antifungal susceptibility and therapeutic efficacy in patients colonised by C. parapsilosis sensu lato were similar to those observed in C. albicans-colonised patients.

A total of 102 Candida species were isolated from blood cultures from January 1997 to October 1999. Using assimilation of carbohydrate test, 52 (51.0%) of the Candida sp. were identified as C. parapsilosis, 25.5% (26) were C. tropicalis. C. albicans made up 11.8% (12), 6.9% (7) were C. rugosa, 3.8% (4) C. glabrata and 1% (1) C. guilliermondii. No C. dubliniensis was found in the study. In vitro antifungal susceptibility tests showed that all Candida species were sensitive to nystatin, amphotericin B and ketoconazole. Although all isolates remained sensitive to fluconazole, intermediate susceptibility was found in 3 C. rugosa isolates. Antifungal agents with high frequency of resistance were econazole, clotrimazole, miconazole and 5-fluorocytosine. Candida species found to have resistance to these antifungal agents were non-C. albicans.

A 57-year-old female, born in Laos and who had lived in Thailand prior to immigrating to Canada in 1989, was seen by her physician with a chief complaint of cough and dyspnea. Her chest X-ray showed bilateral pulmonary air fluid levels. A fungus, with a diffusible red pigment, tentatively identified as Penicillium marneffei, was isolated from the patient's bronchial washings and sputum specimens. At 37 degrees C, the fungus converted to a yeast form when cultured on brain heart infusion agar. Microscopic examination of this culture revealed yeast cells that reproduced by fission. The identity of the patient's isolate was confirmed as P. marneffei with an exoantigen test. The patient's serum demonstrated specific antibodies to P. marneffei antigen. Treatment with amphotericin B and ketoconazole resulted in clinical improvement, clearing of chest X-rays and conversion to sero-negativity. Our case is the first recorded diagnosis of imported penicillosis marneffei in Canada. The minimal inhibitory concentrations recorded for the patient's isolate to fluconazole, 5-fluorocytosine, itraconazole and miconazole were 12.5, 0.39,0.195 and0.195 micrograms/ml, respectively.

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 ofCandida spp. andCryptococcus 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 ofC. glabrata (p=0.014) and with flucytosine against strains ofC. neoformans (p=0.041). Differences between MICs and IC50s were observed with fluconazole against strains ofC. albicans (p=0.027),C. tropicalis (p=0.046), andC. neoformans (p=0.041); with miconazole against strains ofC. glabrata (p=0.014); and with amphotericin B against strains ofC. parapsilosis (p=0.025). Ten additional isolates ofC. 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). Only amphotericin B demonstrated fungicidal activity against all the tested yeasts.

The in vitro activity of several new imidazoles, cloconazole, sulconazole, butoconazole, isoconazole and fenticonazole, were compared with those of amphothericin B, flucytosine, and three azoles: econazole, miconazole and ketoconazole against isolates of pathogenic Candida. A total of 186 clinical isolates of 10 species of the genus Candida and two culture collection strains were tested by an agar-dilution technique. Isoconazole was the most active azole, followed by butoconazole and sulconazole. Differences between some of the species in their susceptibility to the antifungal agents were noted. Sulconazole and cloconazole had the highest activity in vitro against 106 isolates of C. albicans. Butoconazole and isoconazole were also very active against isolates of C. albicans, and were the most active azole compounds against 80 isolates of Candida spp.

Chromoblastomycosis, a well-documented chronic fungal infection, represents a specific clinical entity with typical warty cutaneous nodules and a worldwide distribution. Although more prevalent in tropical and subtropical regions, only a few reports are available from Sri Lanka or from Asia. Five etiologic agents of chromoblastomycosis have been recognized worldwide. Of these the majority of infections have been caused by Fonsecaea pedrosoi. During the period from 1952 to 1962, only twelve culturally proven cases of this disease had been recorded from Sri Lanka. The fungus responsible was F. pedrosoi. The present report presents a study of the clinical and mycological features of 71 Sri Lankan patients with chromoblastomycosis for the 16-year period from 1978 to 1993. It documents three etiological agents. Culture identification was made in 69 cases. The three fungal species were Fonsecaea pedrosoi (64), Phialophora verrucosa (3) and a fungus compatible morphologically with F. compacta (2). The isolation of a fungus morphologically compatible with F. compacta is of significance since only 12 cases have been documented in the world's literature so far.

A total of 110 patients of symptomatic otomycosis was investigated, prospectively. Aural swabs were collected on 1st, 7th and 14th day and examined by direct microscopy and culture for fungi. Of these, 80 patients found to be having pure fungal infection, were taken up for mycological and therapeutic study. Fungi belonging to genus Aspergillus were isolated in 76 (95.0%) patients of which Aspergillus niger was the commonest isolate in 46 (57.5%), followed by A. flavus in 27 (33.7%), A. fumigatus in 3 (3.7%), Candida species in 3 (3.7%) and Mucor in 1 (1.2%). The patients were of all age groups but majority were between 21 and 30 years and the male-female ratio was equal. Of the total of 40 male patients, twenty-one were Sikhs using turban. Before developing the symptoms, forty five patients used oil, mixture of oil and garlic juice, antibiotics, steroids, antiseptics or wax solvent as ear drops. Only two patients were diabetic. No patient had fungal infection elsewhere in the body. The patients were called for regular follow-up for three weeks. In forty cases mercurochrome was applied as the antifungal agent after cleaning the external auditory canal, in twenty-three clotrimazole and in rest of the seventeen patients miconazole was used. On 7th day, only 11 (13.7%) patients grew different fungi in culture. They became symptom-free on 14th day and no fungal material could be seen on otoscopy, direct microscopy or culture. Mercurochrome was found to be most effective in these patients.

The imidazole group of miconazole is subject to protonation (pKa approximately 6.5). Earlier we suggested that the direct lethal action (DLA) of miconazole against Candida albicans requires nonprotonated drug molecules. DLA declined in intensity as pH was decreased from 6.0. At pH6.5 most molecules of miconazole exist in the nonprotonated state, but drug also becomes less soluble. Viability studies were designed to assess DLA in relation to alkaline pH. DLA was clearly inhibited with increasing as well as decreasing pH (i.e., pH6.0 and7.0), suggesting that nonprotonated neutral drug molecules must be in solution or in extremely small aggregates to elicit DLA, and that the nonprotonated species itself is more soluble at pH 6.0-7.0 than under more alkaline conditions.

In the late logarithmic or very early stationary phase of the growth cycle, yeast cells of Candida albicans undergo a shift from susceptibility to resistance to the direct lethal action of miconazole. Regulation of this phenotypic shift was examined. Experiments based on viable count determinations and the construction of time-kill curves showed that reestablishment of resistance is independent of both pH and the attainment of some critical viable cell density. However, it was found that development of resistance requires the continued availability of an appropriate energy source toward the end of exponential growth.

A 66-year-old woman presented 3 groups of scaly granulomatous lesions on the right forearm and elbow of six months duration. Direct examination of the scales showed hyphae and culture in lactrimel medium grew Alternaria sp. considered a contaminant. No improvement was observed after six months of treatment with oral griseofulvin. A second culture using half of a biopsy grew Alternaria sp. again and in histologic examination short pigmented fragments of hyphae surrounded by a granulomatous reaction were seen in the derma. The patient had marked improvement after treatment with erythromycin per os and miconazole topically; an atrophic scar remained as the only sign of the fungal infection.

At 5 microM, miconazole prevented the growth of Aspergillus parasiticus Speare in a number of media. Sensitivity to miconazole was increased approximately 10-fold in a medium containing glycerol. At sub-inhibitory concentrations, miconazole stimulated aflatoxin synthesis on media which normally support toxin formation. Miconazole inhibited respiration and altered mitochondrial ultrastructure, suggesting that miconazole inhibits growth and stimulates aflatoxin production by depressing mitochondrial activity.

The in vitro sensitivity (minimum inhibitory concentrations; MICs) of 42 environmental isolates of pathogenic dematiaceous fungi to 7 azole compounds, viz. thiabendazole, ketoconazole, miconazole, econazole bifonazole, Bay n 7133, Bay 1 9139 and phenylpropyl-morpholine derivative, Ro14-4767/002 was studied by an agar dilution method using Emmon's Sabouraud dextrose agar (ESDA) as the culture medium. The isolates of Fonsecaea pedrosoi, Cladosporium carrionii, Exophiala jeanselmei and Ramichloridium subulatum were most sensitive to bifonazole with mean MICs of 0.06 microgram/ml or less; Phialophora verrucosa had an MIC of 0.05 microgram/ml to ketoconazole and Ro14-4767/002, respectively. Ochroconis sp had an MIC of 0.025 microgram/ml to Ro14-4767/002 and Cladosporium tennuisimum 0.39 microgram/ml to ketoconazole. Econazole and thiabendazole also showed good antifungal activity. The fungi were relatively resistant to the more recently developed azoles, viz. Bay n 7133 and Bay 1 9139, the later failing to inhibit C. tennuisimum at a concentration of 100 micrograms/ml. The minimum fungicidal concentrations (MFC) of the drugs were mostly within 2 to 8 fold of the MICs.

Bay n 7133 and Bay L 9139 (Bayer AG, Wuppertal, Fed. Rep. Germany) are new, orally absorbable, antifungal imidazole derivatives. In vitro, Bay n 7133 was comparable to ketoconazole and miconazole when tested against isolates of Candida albicans and Cryptococcus neoformans. Bay L 9139 also was active against these organisms but to a lesser degree than the other imidazoles. LY 121019, an analog of echinocandin B, was also tested. It proved to be the most active antimycotic against C. albicans but the least active against C. neoformans. Optimal results were obtained in tests employing Kimmig's agar, a medium previously described for use in susceptibility tests with antifungal agents.

The susceptibility of 21 strains of Aspergillus (11 of A. fumigatus, 8 of A, niger, and 2 of A. flavus) isolated from human pathologic specimens to Amphotericin B and Miconazole has been comparatively studied. Determination of the minimal inhibitory concentration of both drugs in a liquid medium showed a noticeably variability for the different strains. The values obtained for Amphotericin B varied between 0.25 microgram/ml (2 strains) and 1.25 microgram/ml (5 strains) after 48 hours, and between 1,25 microgram/ml (1 strain) and 50 microgram/ml (1 strain) after 10 days. For Miconazole the results varied between 0.1 microgram/ml (1 strain) and 25 microgram/ml (1 strain) after 48 hours of incubation, and between 0.5 microgram/ml (5 strains) and greater than 100 microgram/ml after 10 days. The variability of these results indicates the usefulness of carrying our in vitro sensitivity studies whenever it is possible.

The authors used a semi-automatic device, Pfizer Autobac 1, to standardize antifungal antibiotic sensitivity testing. The first trials gave quite satisfying results for true (polyene) antibiotics, but more questionable results were obtained for imidazole derivatives and 5-fluorocytosine.

Thirty-nine isolates of Cryptococcus neoformans, nineteen serotype AD and twenty serotype BC, were assayed for susceptibility to eight antifungal agents using an in vitro agar dilution assay. Media employed were Kimmig agar and yeast nitrogen base supplemented with 10% glucose. The antifungal agents used were ketoconazole, amphotericin B, 5-fluorocytosine, nystatin, miconazole, BAY N 7133, ICI 153,066, and itraconazole. No clinically significant differences in in vitro minimum inhibitory concentrations were detected between serotypes AD and BC against any of the compounds tested. An adverse medium effect was observed in two of the assays, but the outcome of the AD/BC comparison was not affected. This is the first report in which the in vitro antifungal susceptibilities of Cryptococcus neoformans serotypes are analyzed.

The inhibitory activity of some antifungal agents against 17 strains of genus Epidermophyton have been studied. The behaviour of Epidermophyton stockdaleae against antifungal agents tested is clearly different from that observed in the strains belonging to Epidermophyton floccosum, since all of the latter were sensitive to the antifungal agents used and the geophilic species showed resistance to griseofulvin, isoconazole, natamycin and nystatin, and intermediate sensitivity to ketoconazole and miconazole. The low sensitivity of E. stockdaleae (and other geophilic dermatophytes) to antifungal agents could be a problem in the current therapy if further studies or case reports demonstrate their pathogenic role.

A mycotic keratitis case which was caused by Curvularia lunata var. aeria in a patient with an injury in the eye is described. The diagnosis was based on the mycologic analysis of several samples taken from the ulcer of cornea. In vitro tests of the sensitivity of the isolated species to several antifungal drugs were made. The results were related to the response in vivo to the treatment.

The antimicrobial activity of amphotericin B, 5-fluorocytosine, nystatin, clotrimazole and miconazole were compared in vitro against 244 strains of yeasts that had been isolated from clinical specimens. The yeasts used in this study included 20 species of Candida, Cryptococcus, Saccharomyces Geotrichum, Rhodotorula, Torulopsis and Trichosporon. The majority of the strains (78%) had an MIC of less than or equal to 0.5 microgram/ml for amphotericin B, 81% an MIC of less than or equal to 1 microgram/ml for 5-fluorocytosine, 99% less than or equal to 8 micrograms/ml for nystatin, 91%, less than or equal to 8.0 micrograms/ml for clotrimazole and 98% had an MIC of less than or equal to 4.0 for miconazole. Of the anti-fungal agents tested, 5-fluorocytosine and nystatin were found to have the greatest antifungal activity.

Recent studies in our laboratory clearly showed that 4 • 10 -5 M tioconazole or miconazole (i.e. 15-16/xg/ml) caused rapid 2to 3-log reductions in colony forming units (CFU)/ml when added to early logarithmic phase yeast cultures of Candida albicans or Candida parapsilosis growing at 37 ~ with aeration (1, 2). In a more recent report concerned with effects of antifungal azoles on the ATP content of C albicans, Odds, Cheesman & Abbott (3) incidentally mentioned that they were unable to demonstrate the lethal action observed in our experiments. More specifically, it was stated that: 'in our hands neither miconazole nor tioconazole caused the rapid diminution of viable counts described by Beggs, even with exponential-phase yeast cells (E C. Odds & A. B. Abbott, unpublished results)'. Here I wish to provide the most probable explanation of this apparent discrepancy. In our azole drug studies we routinely use a pH 7.0 liquid medium containing yeast nitrogen base, Lasparagine, and glucose (1). After dissolving these three major components in deionized water, the broth is adjusted from pH 5.3 to pH 7.0 with 2 N NaOH and filter sterilized. Cultures are incubated at 37 ~ with shaking at 150 rpm. Details of the unpublished viability studies mentioned by Odds et al. (3) were not given, but in the methods section they stated: 'Yeast-form cells were grown in a broth containing Mycological peptone (Oxoid), 10 g 1-1 and glucose, 40 g 1.2 shaken at 160 rpm and 37~ in air'. The pH of this mycological peptone medium was not stated, but in company literature prepared in England and obtained from Oxoid U.S.A. Inc. (Columbia, Maryland) a dilute solution of the peptone is reported to be at pH 5.4. Details of the viable count time-kill type of experiment presented in Fig. 1 were outlined in our earlier report (1). Data graphically summarized in Fig. 1 clearly show that the fungicidal action of tioconazole against C albicans that occurred in pH 7.0 medium did not occur when the same medium was used at pH 5.5. We recently have made similar observations with miconazole and have confirmed the findings with another strain of C albicans (i.e. ATCC 26790). Thus, the rapid fungicidal action of tioconazole, miconazole, and probably certain other azoles appears to be a highly pH-dependent phenomenon that does not occur under even moderately acidic conditions.

At greater than or equal to 10(-5) M, miconazole (MCZ) can exert a direct physicochemical cell-damaging lethal action against logarithmic phase yeasts of Candida albicans. The imidazole moiety of MCZ has a pKa approximately 6.5. Thus, in media of pH greater than 6.5 most drug molecules are nonprotonated (MCZ degrees). Conversely, at pH less than 6.5 the majority are protonated and carry a positive charge (MCZH+). Our earlier work suggesting that MCZ degrees is required for direct lethal action was tested further. In support of such a requirement, we established a minimal lethal concentration of MCZ degrees (i.e. 5 x 10(-6) M) that was relatively independent of pH, MCZ concentration, and MCZ degrees:MCZH+ ratio.

We describe a case of tinea unguis in a 20 year old female student from Caracas. The peri-ungual skin of a thumb appeared altered first and, since 6 months, the lamina was being progressively invaded and destroyed. At the direct mycologic examination numerous, regular and irregular, hyaline fungal hyphae were visible. Culture was performed 9 times: several molds did grow, among which, eight times, we got numerous colonies of a strain that has been identified to Nannizzia gypsea (+). Owing to the rarity of the observation the bases for the diagnosis are discussed and the pertinent literature is reviewed.