In vitro susceptibility of dermatophytes to oral antifungal drugs and amphotericin B in Uttar Pradesh, India.

BACKGROUND: Dermatophytosis is a major public health problem in our country. Although resistance to conventional oral and topical antifungal agents is being increasingly encountered, the sensitivity pattern of dermatophytes has not been systematically analysed. AIMS: We aimed to determine the sensitivity pattern of dermatophyte isolates to amphotericin B and six oral antifungal drugs. MATERIALS AND METHODS: Patients with dermatophytosis attending the outpatient department of dermatology were enrolled in the study. Samples were collected for mycological examination and in vitro antifungal sensitivity testing was done by broth microdilution as per the Clinical and Laboratory Standard Institute M38-A standards. RESULTS: A total of 804 patients were enrolled. Specimens from 185 patients (23%) were both KOH and culture positive, and 44 of these isolates (41 Trichophyton mentagrophytes and 3 Trichophyton rubrum) were subjected to sensitivity testing. Minimum inhibitory concentrations (MIC) of itraconazole, ketoconazole, voriconazole and amphotericin B were comparable. The median MIC to fluconazole was higher than the other tested drugs. Dermatophytes were most susceptible to ketoconazole and voriconazole, followed by itraconazole, amphotericin B, fluconazole and griseofulvin. A high incidence of resistance was found to terbinafine and the difference was statistically significant in comparison to fluconazole, itraconazole, voriconazole, ketoconazole (P = 0.001) and griseofulvin (P = 0.003). The strains were more sensitive to amphotericin B as compared to griseofulvin (P = 0.02) and terbinafine (P < 0.001). LIMITATIONS: This was a hospital-based study and may not reflect the true pattern in the community. Only a few of the isolates were selected for study. The clinical response of patients, whose isolates were studied for in vitro sensitivity of the antifungals, was not studied. CONCLUSIONS: The sensitivity pattern of dermatophytes to various antifungals including amphotericin B, ketoconazole, voriconazole and itraconazole were determined. The studied isolates were least susceptible to terbinafine.

Diversity, in-vitro virulence traits and antifungal susceptibility pattern of gastrointestinal yeast flora of healthy poultry, Gallus gallus domesticus.

BACKGROUND: Poultry farming and consumption of poultry (Gallus gallus domesticus) meat and eggs are common gastronomical practices worldwide. Till now, a detailed understanding about the gut colonisation of Gallus gallus domesticus by yeasts and their virulence properties and drug resistance patterns in available literature remain sparse. This study was undertaken to explore this prevalent issue. RESULTS: A total of 103 specimens of fresh droppings of broiler chickens (commercial G domesticus) and domesticated chickens (domesticated G domesticus) were collected from the breeding sites. The isolates comprised of 29 (33%) Debaryozyma hansenii (Candida famata), 12 (13.6%) Sporothrix catenata (C. ciferrii), 10 (11.4%) C. albicans, 8 (9.1%) Diutnia catenulata (C. catenulate), 6 (6.8%) C. tropicalis, 3 (3.4%) Candida acidothermophilum (C. krusei), 2 (2.3%) C. pintolopesii, 1 (1.1%) C. parapsilosis, 9 (10.2%) Trichosporon spp. (T. moniliiforme, T. asahii), 4 (4.5%) Geotrichum candidum, 3 (3.4%) Cryptococcus macerans and 1 (1%) Cystobasidium minuta (Rhodotorula minuta). Virulence factors, measured among different yeast species, showed wide variability. Biofilm cells exhibited higher Minimum Inhibitory Concentration (MIC) values (µg/ml) than planktonic cells against all antifungal compounds tested: (fluconazole, 8-512 vs 0.031-16; amphotericin B, 0.5-64 vs 0.031-16; voriconazole 0.062-16 vs 0.062-8; caspofungin, 0.062-4 vs 0.031-1). CONCLUSIONS: The present work extends the current understanding of in vitro virulence factors and antifungal susceptibility pattern of gastrointestinal yeast flora of G domesticus. More studies with advanced techniques are needed to quantify the risk of spread of these potential pathogens to environment and human.