title: Emergence of Aureobasidium pullulans as human fungal pathogen and molecular assay for future medical diagnosis.
abstract: Despite the great importance of Aureobasidium pullulans in biotechnology, the fungus had emerged as an opportunistic human pathogen, especially among immunocompromised patients. Clinical detection of this rare human fungal pathogen presently relies on morphology diagnosis which may be misleading. Thus, a sensitive and accurate quantitative molecular assay for A. pullulans remains lacking. In this study, we presented the microscopy observations of A. pullulans that reveals the phenotypic plasticity of the fungus. A. pullulans-specific primers and molecular beacon probes were designed based on the fungal 18S ribosomal RNA (rRNA) gene. Comparison of two probes with varied quencher chemistry, namely BHQ-1 and Tamra, revealed high amplification efficiency of 104% and 108%, respectively. The optimized quantitative real-time PCR (qPCR) assays could detect and quantify up to 1 pg concentration of A. pullulans DNA. Both assays displayed satisfactory performance parameters at fast thermal cycling mode. The molecular assay has great potential as a molecular diagnosis tool for early detection of fungal infection caused by A. pullulans, which merits future study in clinical diagnosis.
authors: Nanoporous Materials for Biological Application Research Group (NAMBAR), Sustainability Research Alliance, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia. giekfar@utm.my
authors: Giek Far
authors: GF
authors: Chan
authors: Mohamad Safwan Ahmad
authors: MS
authors: Puad
authors: Chai Fung
authors: CF
authors: Chin
authors: Noor Aini Abdul
authors: NA
authors: Rashid
mesh_terms: D001203:Ascomycota / Q000235:genetics / Q000302:isolation & purification*; D001483:Base Sequence; D001681:Biological Assay; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics*; D004271:DNA, Fungal / Q000032:analysis*; D042241:Early Diagnosis; D006801:Humans; D016867:Immunocompromised Host; D008853:Microscopy; D008969:Molecular Sequence Data; D009181:Mycoses / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D009894:Opportunistic Infections / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D010641:Phenotype; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012235:Rhodamines / Q000032:analysis
chemical_list: C114557:5-carboxytetramethylrhodamine succinimidyl ester; D015342:DNA Probes; D004271:DNA, Fungal; D012337:RNA, Ribosomal, 18S; D012235:Rhodamines