Phenotypes characterization and ABC genotypes distribution of clinical Candida albicans isolates.

BACKGROUND: Candidemia and vaginitis are the most common types of candidiasis mostly caused by Candida albicans species. C. albicans has several genotypes and the potential ability to form different phenotype colonies on specific media. This study aimed to evaluate the genotype distribution of blood and vaginal C. albicans isolates and phenotype characteristics on Spider and yeast peptone dextrose agar medium. METHODS: A total of 40 clinical Candida albicans isolates comprising vagina (20) and blood (20) were used. ABC typing using CA-INT-R and CA-INT-L primers was performed to span the transposable group I intron of the 25S rDNA gene. For colony phenotypic characteristics, the Spider and YPDA media were used. RESULTS: Among the blood and vaginal isolates, genotype A (12/60%) and genotype C (10/50%) were the most common types, respectively. The highest phenotype shape frequency of the colonies in blood and vaginal samples was the ring and the lowest was the hat/ring. The dominant color phenotype in blood and vaginal samples was gray. There was a significant relationship between genotype and phenotype forms in the blood sample on YPDA medium (p = 0.02). In the Spider medium, there were no significant differences between genotypes and phenotypes. CONCLUSION: In this study, genotype A and genotype C were predominant in blood and vaginal samples, respectively. In both groups, YPD agar medium demonstrated the most variety of phenotypes that was related to genotypes A and C. The variety of phenotypes in both groups was the same in genotypes A and C on the Spider medium.

Evaluation of different DNA extraction methods based on steel-bullet beating for molecular diagnosis of onychomycosis.

BACKGROUND: Considering increased trends toward molecular methods for detection/identification of fungi causing onychomycosis, the aim of this study is comparison three DNA extraction methods based on steel-bullet beating to extract DNA from nail. METHODS: Ex -vivo onychomycosis model was developed using bovine hoof with Candida albicans and Aspergillus flavus. For two models, total DNA was extracted using the three different methods. In method 1, the extraction and purification were performed by steel-bullet beating and phenol chloroform protocol, respectively. In method 2, a freezing step were applied before beating. The purification step in method 3 was carried out using a commercial kit, although DNA extraction was done similarly to method 1 in that approach. To evaluate the efficacy of each method, the extracted genomic DNA was amplified with Polymerase Chain Reaction (PCR) using Internal Transcribed Spacer (ITS) regions. Moreover, 50 nail samples were evaluated for onychomycosis using direct microscopy examination as well as PCR in order to evaluate the diagnostic efficiency of the optimal DNA extraction method. RESULTS: Regarding the desirable quality of the extracted DNA, cost effectiveness, and simplicity, method 1 could be used to extract DNA effectively. Additionally, the obtained data showed that PCR had a higher detection rate of fungal agents in the nail samples than direct microscopic examination. CONCLUSIONS: This study demonstrated that the mechanical disruption of the cell wall by steel-bullet beating is a useful and practical method to improve the quantity and quality of fungal DNA thorough the extraction process.

Molecular characterization and antifungal activity against non-dermatophyte molds causing onychomycosis.

Onychomycosis is a fungal disease that caused by different types of fungi. Non-dermatophyte molds are a large saprophytic fungi group that live in nature and could affect traumatic nails. The aim of this study was to identify non-dermatophyte molds causing onychomycosis and evaluation of several antifungal activities against the isolates. The samples consisted of 50 non-dermatophyte molds isolated from patients with onychomycosis confirmed by direct and culture examination fungal. DNA was extracted, amplified, and sequenced. Disk diffusion method was used to evaluate itraconazole, fluconazole, ketoconazole, terbinafine, posaconazole, and econazole activity against the isolates. The species identified as: Aspergillus flavus 22 (44%), A. niger 12 (24%), A. fumigates, 3 (6%), A. sydowii 3 (6%), A. terreus 1 (2%), Penicillium commune 2 (4%), P. glabrum 2 (4%), P. chrysogenum, 1 (2%), Fusarium solani 3 (6%) and F. thapsinum 1 (2%). Most of the samples were sensitive to terbinafine, itraconazole, and econazole and 94% of the isolates were resistant to fluconazole. This study showed that Aspergillus species were the most common cause of non-dermatophyte mold onychomycosis and fluconazole was the most resistant antifungals. Care must be taken to choose the appropriate antifungal drug for a better cure.

Molecular identification of Malassezia species isolated from neonates hospitalized in Neonatal intensive care units and their mothers.

Background and Purpose: Given the important role of Malassezia spp. in skin diseases and other associated infections in neonates, this study aimed to investigate the presence and frequency of Malassezia spp. in the skin of neonates hospitalized in neonatal intensive care units and their mothers using culture and accurate molecular-based methods. Materials and Methods: In total, 205 samples were collected from 130 neonates (>4-day-old) and 75 mothers. Isolation of Malassezia spp. from the skin was performed using Leeming-Notman agar and modified Dixon agar media. To compare the Malassezia microflora on the skin of the neonates and their mothers, a polymerase chain reaction-sequencing method was performed for spp. identification of 92 isolates obtained from neonates and their mothers. Moreover, possible associated risk factors for the colonization of Malassezia spp. on the skin were recorded. Results: Cultures from 62.3% of neonates and 77.3% of mothers were positive for Malassezia spp. growth. Malassezia globosa was the most prevalent isolated spp. found in the skin of the study population. It is noteworthy that a rare Malassezia spp., Malassezia arunalokei, was isolated from the skin of one neonate. There was a 76% similarity between the mother-neonate isolate sequences results. The statistical analysis showed that the type of feeding is a significant (P<0.001) associated factor for Malassezia skin colonization. Conclusion: The findings support the hypothesis that the colonization of Malassezia in neonates is significantly influenced by that of the mother, and this may be associated with breastfeeding.