The effects of peracetic acid solution on the treatment of otomycosis in an animal model: a new antifungal drug?

OBJECTIVE: This study aimed to investigate the therapeutic effects of 1 per cent and 0.01 per cent peracetic acid as an antifungal agent in animal otomycosis. METHOD: After creating a superficial scratch in the external auditory canal of guinea pigs, a suspension of Aspergillus niger, Aspergillus fumigatus and candida were inoculated into the ears of the animals. After otomycosis, the effect of 1 per cent or 0.01 per cent peracetic acid on otomycosis was evaluated by otomicroscopy and culture at 10 days post-treatment and compared with 2 per cent acetic acid as the control. RESULTS: A 10-day treatment with 1 per cent peracetic acid and 2 per cent acetic acid (control) showed normal otomicroscopy and negative cultures compared with 0.01 per cent peracetic acid. Drug sedimentation or other side effects in the external auditory canal or tympanic membrane were not observed during treatment with peracetic acid. CONCLUSION: The findings of this study confirm that the treatment of otomycosis with 1 per cent peracetic acid in an animal model is beneficial and may be a novel therapeutic treatment for otomycosis.

Voriconazole resistance genes in Aspergillus flavus clinical isolates.

OBJECTIVE: The present study was designed to discover novel biomarkers involved in voriconazole resistance in clinical isolates of Aspergillus flavus. MATERIALS AND METHODS: Two voriconazole non-wild-type and two voriconazole-wild-type A. flavus clinical isolates were selected to evaluate possible molecular mechanism involved in A. flavus resistance to voriconazole using the mutation assessment, Quantitative real- time PCR of cyp51A and cyp51C genes and complementary DNA- amplified fragment length polymorphism technique. RESULTS: No mutations were seen in the cyp51A and cyp51C genes in voriconazole non-wild-type isolates compared to wild- type and reference strains. Regarding to mRNA expression results, no changes were observed in expression fold of cyp51A and cyp51C mRNA expression level in first non- wild- type isolate compared to wild-type isolate. For second isolate cyp51C mRNA expression level was down regulated (5.6 fold). The set of genes including ABC fatty acid transporter XM- 002375835 and aldehydereductase XM- 002376518 and three unknown functional genes were identified. Based on results, the over-expression of AKR1 and ABC fatty acid transporter in the voriconazole non- wild- type isolates suggests these genes could represent a novel molecular marker linked to the voriconazole resistance in A. flavus. CONCLUSION: The results obtained in this study showed a novel finding as the authors identified AKR1 and ABC fatty acid transporter genes as possible voriconazole target genes in Iranian clinical isolates of A. flavus.

Comparative in vitro activities of seven antifungal drugs against clinical isolates of Candida parapsilosis complex.

OBJECTIVE: Candida parapsilosis species complex, an important set of non-albicans Candida species, is known to cause candidaemia particularly in neonates and infants. However, the incidence has increased in recent years, owing to higher numbers of at individuals at risk for these infections. Our objective was to evaluate the in vitro susceptibility of clinical isolates of C. parapsilosis complex isolates from Iran to seven antifungal drugs. MATERIAL AND METHODS: One hundred-one clinical isolates of C. parapsilosis species complex cultured from humans were included. Species identification had been previously confirmed by combined phenotypic characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry-based assay and reconfirmed by DNA sequence analysis of the ITS rDNA region and D1/D2 gene. Minimum inhibitory concentrations (MICs) for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, micafungin and anidulafungin were determined against well-characterized isolates by broth microdilution susceptibility testing according to the CLSI M27-A3 guideline. RESULTS: Species identifications were performed on 101 isolates, of which 88 (87.2%) C. parapsilosis sensu stricto and 13 (12.8%) C. orthopsilosis. Amphotericin B and posaconazole were the most active drugs with 100% of isolates being wild-type (WT). Voriconazole and micafungin, 99% of isolates were WT. The low activity was recorded for fluconazole and itraconazole with 93.1% and 89.1% of isolates being WT, respectively. At the species level, all Candida parapsilosis sensu stricto isolates were WT to amphotericin B and posaconazole and all Candida orthopsilosis isolates were WT to amphotericin B, voriconazole, posaconazole, anidulafungin and micafungin. In contrast, the highest rate of non-WT was observed in C. orthopsilosis to itraconazole (4 of 13, 30.8%). CONCLUSIONS: Although almost all of the tested drugs demonstrated potent activity against C. parapsilosis species complex, it seems that more especially C. orthopsilosis isolates had decreased susceptibility to itraconazole. Further studies are needed to determine how these findings may switch into in vivo efficacy.