ABSTRACT
Early detection of Candida species in body site could improve the survival of the immunosuppressed patients by allowing the initiation of specific treatment while the fungal biomass is still low. The aim of this study was the identification of Candida albicans isolated from the oncology patients by molecular methods. Sixty two of Candida albicans isolated identified by phenotypic methods [color of colony on CHROMagar medium, germ-tube formation in horse serum, chlamydospore formation on Cornmeal agar with 1% Tween 80]. DNA was extracted by using a glass bead/phenol-chloroform method. The oligonucleotide primer pairs [NL1/NL4] were used to amplify a 620bp fragment of D1/D2 region of large submit [26s] ribosomal DNA gene. PCR-products were electrophoresed in a 1.5% agarose gel. Eighteen PCR-amplified products sequenced and results were evaluated by online BLAST software. Multiple sequence alignment was performed by using online CLUSTAL-W [version 1.83] software. The BLAST search revealed that all of products were Candida albicans. All sequences showed >99% similarity when compared with known reference sequences at the Gene-Bank. Four different strains were obtained of albicans species, including: AA 1622b [13 samples], 24698 [3 samples], TA 62 [1 samples] and 551 FC [1 sample]. A total of 131 nucleotide exchange sites were revealed. The dominant species by phenotypic approaches was Candida albicans. In addition, identification of Candida albicans by [26S] rDNA sequencing was 100% concordant to the results obtained by the phenotypic methods
Subject(s)
Humans , Medical Oncology , Hospitals, University , Molecular Diagnostic TechniquesABSTRACT
To report the prevalence of fungal keratitis as a cause of corneal ulcer in patients referred to Boo-Ali Sina Hospital in Sari and identify the predisposing factors. This prospective study was conducted on patients who presented with corneal ulcers to the ophthalmology ward at Boo-Ali Sina Hospital in Sari, 2004-2005. Using standard techniques, a corneal scraping was performed by an ophthalmologist. Material obtained from the scraping was hydroxide [KOH] with or without calcofluor white [KOH + CFW] stain for fungal keratitis. Specimens were inoculated directly onto blood agar, Sabouraud's dextrose agar, and potato dextrose agar in C-shaped streaks. A total of 22 patients were examined including 10 female [45.5%] and 12 male [54.5%] subjects. Average age was 61.5 +/- 17.7 years [range: 15-83 years]. Branching septate hyphae were identified in 7 patients [31.8%] including five male and 2 female subjects; two of these specimens fungal keratitis was 60.4 +/- 12.1 years [range: 39 to 73 years]. Three patients with fungal keratitis were farmers. The mean interval between onset of symptoms and diagnosis was 26.4 days with a keratitis. Five cases of fungal keratits had received topical antibiotics. Analyses using KOH + CFW as the golden standard revealed individual sensitivities for detection of fungi to be 71.4% and 42.9% for KOH and Gram stain, respectively. Infections of the cornea due to filamentous fungi are frequent cause of corneal damage and should always be kept in mind. Direct microscopy is an essential tool in the diagnosis of fungal keratitis. Mounts with KOH+CFW or KOH alone can be relied upon as the single most important method for rapid diagnosis of fungal corneal ulcer