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Whole Genome Sequencing of Candida glabrata for Detection of Markers of Antifungal Drug Resistance
Published on: December 28, 2017
Molecular identification and distribution profile of Candida species isolated from Iranian patients
Rasoul Mohammadi1, Hossein Mirhendi, Ali Rezaei-Matehkolaei
1Department of Medical Mycology, School of Medicine, Tarbiat Modares University, Tehran, Iran.
Abstract:
A total of 855 yeast strains isolated from different clinical specimens, mainly nail (42%) and vulva-vagina (25%) were identified by a set of polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Genomic DNA was extracted from fresh colonies using Whatman FTA Card technology. PCR assays were performed on the complete ribosomal DNA internal transcribed spacer (rDNA-ITS) region for all isolates and species identification was carried out through their specific electrophoretic profiles after digestion with the enzyme MspI. Those isolates suspected as Candida parapsilosis group were then subjected to amplification of the secondary alcohol dehydrogenase (SADH) gene and restriction digestion with NlaIII enzyme. In total, 71.1% of the strains were obtained from females and 28.9% from males. The age group of 31-40 years consisted of the highest frequency of patients with candidiasis. Candida albicans was the predominant species (58.6%) followed by C. parapsilosis (11.0%), C. glabrata (8.3%), C. tropicalis (7.0%), C. kefyr (5.8%), C. krusei (4.4%), C. orthopsilosis (2.1%), and C. guilliermondii (0.6%). A few strains of C. lusitaniae, C. rugosa, C. intermedia, C. inconspicua, C. neoformans and S. cerevisiae were isolated. We could not identify 8 (0.9%) isolates. Candida albicans remains the most frequently species isolated from Iranian patients; however, the number of non-C. albicans Candida species looks to be increasing. The simple and reliable PCR-RFLP system used in the study has the potential to identify most clinically isolated yeasts.
Insights
This study identified 855 yeast strains from clinical samples using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Candida albicans was most common, but non-albicans Candida species are increasing, highlighting the need for accurate yeast identification.
Area of Science:
- Medical Mycology
- Clinical Microbiology
- Molecular Diagnostics
Background:
- Yeast infections pose a significant public health challenge.
- Accurate identification of yeast species is crucial for effective treatment and epidemiological surveillance.
- The prevalence of non-albicans Candida species is increasing globally.
Purpose of the Study:
- To identify yeast strains isolated from clinical specimens in Iran.
- To evaluate the utility of polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) for yeast identification.
- To determine the prevalence of different Candida species, including non-albicans species.
Main Methods:
- Isolation and identification of 855 yeast strains from clinical samples (nail, vulva-vagina).
- DNA extraction using Whatman FTA Card technology.
- Identification using PCR amplification of the ribosomal DNA internal transcribed spacer (rDNA-ITS) region and enzyme digestion (MspI).
- Further identification of Candida parapsilosis group using secondary alcohol dehydrogenase (SADH) gene amplification and NlaIII digestion.
Main Results:
- Candida albicans was the predominant species (58.6%), followed by C. parapsilosis (11.0%).
- Non-albicans Candida species, including C. glabrata, C. tropicalis, and C. kefyr, showed notable prevalence.
- The PCR-RFLP method demonstrated reliability in identifying most clinically isolated yeasts.
- The majority of isolates (71.1%) were from female patients, with the 31-40 age group most affected.
Conclusions:
- Candida albicans remains the most common yeast pathogen in Iranian patients.
- There is an observable increase in the isolation of non-albicans Candida species.
- The PCR-RFLP technique is a simple, reliable, and effective method for identifying clinically significant yeasts.
