Oral Candida isolates in patients undergoing radiotherapy for head and neck cancer: prevalence, azole susceptibility profiles and response to antifungal treatment.

Oral pseudomembranous candidiasis and mucositis were assessed in 39 patients receiving a total dose of 39-70 Gy radiotherapy for head and neck cancer. Mucositis was scored using the Radiation Therapy Oncology Group criteria, and oral candidiasis was diagnosed on the basis of clinical evaluation and quantitative laboratory findings. Radiation-induced mucositis was observed in 9/39 patients. Only 3/39 patients discontinued radiotherapy due to acute severe mucosal effects. Candidiasis (colony-forming units 35 to > or = 60/lesion) associated with mucositis was diagnosed in 30/39 patients: the most frequent aetiology of the infection was Candida albicans (n = 23), followed by Candida glabrata (n = 3), Candida krusei (n = 2), Candida tropicalis (n = 1) and Candida kefyr (n = 1). Patients with confirmed oral pseudomembranous candidiasis were treated with either fluconazole 200 mg/day or itraconazole 200 mg/day for 2 weeks. Clinical improvement and concomitant negative Candida cultures (mycologic cure) were the criteria determining a response to antifungal treatment. Etest revealed very low voriconazole MICs (0.004-0.125 microg/ml) for all isolates, and fluconazole resistance for eight C. albicans strains (MIC > 64 microg/ml) and for the C. krusei isolates (MIC > 32 microg/ml). The same strains showed itraconazole susceptibility dose dependence (MIC 0.5 microg/ml). Despite the itraconazole susceptible dose dependent MIC readings, all patients with oral pseudomembranous candidiasis caused by these strains responded to antifungal treatment with 200 mg/day itraconazole. Oral mycologic surveillance of patients undergoing radiotherapy for head and neck malignancies and susceptibility testing of isolates may be indicated in cases with mucositis-associated confirmed oral pseudomembranous candidiasis to ensure prompt administration of targeted antifungal treatment. On the basis of the low MIC values found, clinical evaluation of voriconazole is indicated for management of oral pseudomembranous candidiasis refractory to other azoles.

First report of Cryptococcus laurentii meningitis and a fatal case of Cryptococcus albidus cryptococcaemia in AIDS patients.

We report the first case of Cryptococcus laurentii meningitis and a rare case of Cryptococcus albidus cryptococcaemia in AIDS patients. Both infections were treated with amphotericin B and flucytosine. The C. laurentii meningitis was controlled after 2 weeks of treatment with no evidence of infection 20 months later. The patient with C. albidus cryptococcaemia, despite the amphotericin B/flucytosine combination therapy, died on the 14th day of treatment. The minimum inhibitory concentrations (MICs) for C. laurentii, as determined by Etest on RPMI 1640 agar, were 0.25 microg ml(-1) of amphotericin B, 1.25 microg ml(-1) flucytosine, 4 microg ml(-1) fluconazole, 0.50 microg ml(-1) itraconazole and 1.0 microg ml(-1) of ketoconazole. The MIC of amphotericin B for C. albidus was 0.5 microg ml(-1), flucytosine 1.25 microg ml(-1), fluzonazole 4 microg ml(-1), itraconazole 0.5 microg ml(-1) and ketonazole 0.25 microg ml(-1). The agreement of the amphotericin B MIC values obtained in antibiotic medium 3 by the broth microdilution method, with those obtained on casitone medium by Etest, was within a two-dilution range for both isolates. C. laurentii may cause meningitis and may also involve the lungs in AIDS patients.

Effect of glucose and thiamine concentrations on the formation of macroconidia in dermatophytes. Occurrence of dysgonic Microsporum canis strains in Athens, Greece.

Data collected from multiple trials with 110 fresh and preserved clinical isolates of Trichophyton mentagrophytes var. mentagrophytes, T. violaceum, T. rubrum, T. verrucosum, Microsporum canis and Epidermophyton floccosum revealed that production of macroconidia depends on glucose and thiamine concentrations in the medium. Optimal macroconidia production was obtained at the critical concentrations of 5 g l-1 glucose and 0.6 g l-1 thiamine when the two compounds were used in combination. The same conditions also encouraged macroconidia production in aconidial strains of T. verrucosum. Cutaneous inoculation in immunocompetent laboratory rabbits further enhanced the macroconidia producing capacity of the tested strains. Emphasis was placed on the occurrence of dysgonic/atypical strains of M. canis, which readily reverted to their typical phenotypes after growth on medium supplemented with 0.6 g l-1 thiamine, a process greatly augmented after cutaneous animal inoculation. It was verified that selective exogenous factors affect macroconidial production and that the dysgonic group of M. canis constitutes an epidemiologically significant group in the Greater Athens area. This is the first report of the occurrence of such M. canis strains from Greece.