Methods for identification of Candida auris, the yeast of global public health concern: A review.

Candida auris has recently emerged as a fungus able to cause severe infections, especially bloodstream infections with high mortality rates. This multi-drug-resistant yeast has the capacity of persistence on environmental surfaces, and has been reported to cause hospital-acquired infections. The development of faster and inexpensive tools for identification is critical to controlling, preventing and establishing early diagnosis of this emerging pathogen. Identification of C. auris by use of conventional laboratory methods is challenging, and it is commonly misidentified as other Candida species. Less expensive, reliable DNA-based tests have been used for identifying C. auris in environmental and clinical samples. Matrix-assisted laser desorption ionization-time of flight mass spectrometry is also a useful tool for identification of cultured isolates. This review provides a succinct overview of the available methods for identification of C. auris with particular emphasis on their relative advantages and drawbacks.

Molecular characterization of Aspergilli isolated from outdoor air.

Ubiquitous airborne conidia of the genus Aspergillus are responsible for a diverse group of human disorders from allergy to life treating invasive aspergillosis and mycotoxicoses. The aim of this study was to determine the population structure of Aspergillus isolated from outdoor air in Tehran by comparing the nucleotide sequences of ITS region and the PCR-RFLP molecular method. Internal transcribed spacer domains of 47 Aspergillus spp. were amplified and sequenced and PCR products were digested individually with restriction enzymes TaqI and EcoRI. For all species the PCR reaction produced a fragment of approximately 600bp in length. All of the nucleotide sequences were highly similar with the corresponding reference sequences registered at the gene bank. The all isolates displayed same banding pattern on the basis EcoR1 cleavage. While Taq1 enzyme profiling provided 5 different banding pattern. The results show that the A. niger section has the highest frequency with 27 isolates (57.4%). Of these, 23 isolates (48.9%) belonged to the A. niger complex and 4 isolates (8.5%) to the A. aculeatus complex. The A. flavus complex was also placed in the next ranking with 9 isolates (19.1%). These results strongly support the need for using molecular markers as an auxiliary tool in differentiating Aspergillus species.

Evaluation of PCR-reverse line blot hybridization assay for simultaneous identification of medically important saprophytic fungi.

BACKGROUND: In immunocompromised patients suffering from invasive fungal infections, rapid identification of fungal species is important since the appropriate treatment is usually related to the responsible species. We describe here, an assay based on combination of PCR and reverse line blot hybridization (PCR/RLB) for differentiation causative agent of fungal infections. MATERIALS AND METHODS: We performed PCR/RLB assay on 10 reference strains, which include Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, and A. clavatus), Mucor circnelloides, Rhizopus oryzae, Alternaria alternata, Cladosporium herbarum, and Fusarium solani. Besides, twenty-two clinical specimens from patients with proven fungal infections were analyzed for the identification of species. The obtained results were then compared with the results of culture and sequence analysis. RESULTS: The fungal species-specific oligonucleotide probes were able to distinguish between all species represented in this study with the exception of cross-reactivity between A. niger and A. fumigatus species. Two specimens, which were represented as mixed fungi in culture, were identified properly by this method. Results of the RLB assay were concordant with the culture and ITS sequencing results. CONCLUSION: Our result demonstrate that the RLB assay potentially is suitable for rapid and simultaneous identification of variety fungal pathogens directly from culture as well as from clinical specimens.

First case of superficial infection due to Naganishia albida (formerly Cryptococcus albidus) in Iran: A review of the literature.

BACKGROUND AND PURPOSE: Naganishia albida (formerly Cryptococcus albidus) is a non-neoformans cryptococcal species rarely isolated as a human pathogen. CASE REPORT: Herein, we present the case of a 26-year-old Iranian man with a superficial cutaneous lesion in the axilla. The initial treatment for pityriasis versicolor by clotrimazole was unsuccessful. We performed skin sampling based on the standard protocol and conducted further investigations by the conventional laboratory tests and molecular analysis of the skin samples. All the mentioned analyses revealed N.albida as the causative agent of infection. The minimum inhibitory concentration (MIC) analysis was carried out for the isolated agent, and the patient was treated using 100 mg daily of oral itraconazole. CONCLUSION: N. albida can be the causative agent of some superficial infections. This is the first report on the successful detection and treatment of a superficial skin infection due to N. albida by oral itraconazole.