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.

Identification of Acanthamoeba spp. from water and soil of public parks in the north of Iran.

Acanthamoeba, a free-living and opportunistic protozoan parasite, is a causative agent of severe human infections of the cornea and brain. The present study evaluated the distribution and genotyping of Acanthamoeba spp. in water and soil of recreational places in various areas in Guilan province in northern Iran. Eighty water and 20 soil samples were collected from the study area. Water samples were vacuum filtered through a 0.45 µm pore-size membrane filter. Soil samples were washed with sterile distilled water, and washings were similarly filtered, as mentioned for water samples. The filtered material was cultured on non-nutrient agar plates seeded with heat-killed Escherichia coli. Molecular analysis was performed by PCR and sequencing using specific primers for Acanthamoeba. Finally, 26 isolates were successfully sequenced. According to culture and PCR methods, 54% of water and 100% of soil samples were contaminated with Acanthamoeba. Based on the sequencing data, genotypes T4 (47%), T5 (35.29%), T3 (11.76%), and T11 (5.88%) were identified in water samples. Genotypes T4 (66.6%), T5 (22.2%) and T15 (11.1%) were identified in water samples. Most isolates might present a potential health hazard for humans in this region. To the best of our knowledge, this is the first comprehensive survey of water and soil of recreational areas in northern Iran and the first report on identifying genotype T15 from soil sources.

Comparison of the RE and B1 gene for detection of Toxoplasma gondii infection in children with cancer.

Early, accurate and effective diagnosis of toxoplasmosis can make an important contribution to the prevention and control of disease, especially in people who are at risk. In this study, two commonly used genomic repeats of Toxoplasma gondii, RE (GenBank accession number AF146527) and B1, were compared to each other in nested-PCR assay. Five hundred and thirty-five blood samples from children with leukemia were tested for the presence of T. gondii antibodies using enzyme immunoassays. One hundred and ten DNA samples of these patients (50 IgM+, IgG+, 10 IgM-, IgG+, and 50 IgM-, IgG-) were analyzed by nested-PCR. The specificity of two nested PCR assays was determined using the DNA samples of other parasites and human chromosomal DNA. As a result, 82% (41/50) and 68% (34/50) of the IgM+, IgG+ samples were positive on duplicate RE and B1-nested PCR analyses, respectively. None of the 10 IgM-, IgG+ seropositive samples was detected positive after testing RE and B1-nested PCR assays in duplicate. One (2%) of the 50 seronegative samples was positive by duplicate RE-nested PCR but none of them were positive by duplicate B1-nested PCR. The detection limit of the RE-nested PCR assay was 640 fg of T. gondii DNA whereas this rate for B1-nested PCR was 5.12 pg of the DNA template. No cross-reactivity with the DNA of other parasites and human chromosomal DNA was found. The results indicate that an RE-based nested PCR assay is more sensitive than B1 genomic target, of those tested, for detection of T. gondii. It is noteworthy that in comparison with B1-nested PCR, RE-nested PCR could detect the T. gondii DNA in seronegative samples too.