title: Multiplex tandem PCR: a novel platform for rapid detection and identification of fungal pathogens from blood culture specimens.
abstract: We describe the first development and evaluation of a rapid multiplex tandem PCR (MT-PCR) assay for the detection and identification of fungi directly from blood culture specimens that have been flagged as positive. The assay uses a short-cycle multiplex amplification, followed by 12 simultaneous PCRs which target the fungal internal transcribed spacer 1 (ITS1) and ITS2 region, elongation factor 1-alpha (EF1-alpha), and beta-tubulin genes to identify 11 fungal pathogens: Candida albicans, Candida dubliniensis, Candida glabrata, Candida guilliermondii, Candida krusei, Candida parapsilosis complex, Candida tropicalis, Cryptococcus neoformans complex, Fusarium solani, Fusarium species, and Scedosporium prolificans. The presence or absence of a fungal target was confirmed by melting curve analysis. Identification by MT-PCR correlated with culture-based identification for 44 (100%) patients. No cross-reactivity was detected in 200 blood culture specimens that contained bacteria or in 30 blood cultures without microorganisms. Fungi were correctly identified in five specimens with bacterial coinfection and in blood culture samples that were seeded with a mixture of yeast cells. The MT-PCR assay was able to provide rapid (<2 h), sensitive, and specific simultaneous detection and identification of fungal pathogens directly from blood culture specimens.
authors.affiliation: Centre for Infectious Diseases and Microbiology, Westmead Hospital, Westmead, New South Wales, Australia.
authors.forename: Anna
authors.initials: A
authors.lastname: Lau
authors.forename: Tania C
authors.initials: TC
authors.lastname: Sorrell
authors.forename: Sharon
authors.initials: S
authors.lastname: Chen
authors.forename: Keith
authors.initials: K
authors.lastname: Stanley
authors.forename: Jonathan
authors.initials: J
authors.lastname: Iredell
authors.forename: Catriona
authors.initials: C
authors.lastname: Halliday
mesh_terms: D002175:Candida / Q000235:genetics; D003455:Cryptococcus neoformans / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D005658:Fungi / Q000235:genetics*; D005670:Fusarium / Q000235:genetics; D005800:Genes, Fungal / Q000235:genetics; D006801:Humans; D009181:Mycoses / Q000175:diagnosis* / Q000382:microbiology; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods*; D021681:Scedosporium / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D017931:DNA Primers