1559. Visible DNA Microarray System as an Adjunctive Molecular Test in the Identification of Pathogenic Fungi Directly from Blood Culture Bottles
Session: Poster Abstract Session: Mycology: Diagnostic
Friday, October 28, 2016
Room: Poster Hall
Background: : The microbiologic diagnosis of pathogenic fungi represents a challenging task. In addition, the identification to species level requires expensive and laboring intensive molecular techniques.

Methods: We evaluated the performance of visible DNA microarray platform designed for the identification of 44 genera/species of pathogenic fungi based on the internal transcribed spacer region. All blood cultures were performed in Bact/ALERT system. The study consisted of the analysis of 125 bottles positive for fungi (14 Candida krusei, 26 Candida albicans, 11 Candida glabrata, 3 Candida dubliniensis, 27 Candida tropicalis, 9 Candida parapsilosis, 2 Candida orthopsilosis, 1 Candida lusitaniae, 1 Candida guilliermondii, 1 Candida pelliculosa, 1 Aspergillus niger, 23 Cryptococcus neoformans, 1 Histoplasma, 2 Saccharomyces cerevisiae, 1 Rhodotorula spp. and 2 Fusarium spp); 30 bottles of negative blood cultures and 303 bottles positive for bacteria. Fungal DNA was extracted directly from a sample of each bottle and the products were sequenced. Microarray results were compared with microbiologic and DNA sequencing identification

Results: Microarray showed concordant results with microbiology in 118 of 125 blood cultures positive for fungi (94.4%); 2 C. orthopsilosis, 1 C. pelliculosa, 2 S. cerevisiae and 1 Rhodotorula spp. could not be identified due to the absence of probes into the platform. No fungal DNA was found in all negative blood cultures. In the blood culture bottles positive for bacteria, microarray identified Candida in 4 blood cultures from 3 individual patients. One patient’s blood culture bottle had C. albicans and another C. tropicalis from bottles previously positive for coagulase negative Staphylococus. Two C. krusei were recovered in 2 bottles, positive for Enterococcus faecium, from the same patient. Sequencing identification was in agreement with microarray. The three patients died before receiving antifungal therapy

Conclusion: : Microarray showed a robust performance in the identification of fungi direct from blood cultures and enabled the identification of several pathogenic fungi. The fast growth of bacteria, in blood cultures may have interfered in the detection of Candida by Bact/Alert resulting in false negative results.

Lais Sturaro, B.Tech1, Tohru Gonoi, PHD2, Kanae Sakae, PHD2, Ariane Busso-Lopes, PHD1, Yuzuru Mikami, PHD2, Plinio Trabasso, MD1, Cibele Tararam, PHD1, Luzia Lyra, B.Tech3, Carlos Emilio Levy, MD3, Hideaki Taguchi, PHD2, Angelica Schreiber, PHD3, Katsuhiko Kamei, MD2 and Maria Luiza Moretti, MD1, (1)Internal Medicine, University of Campinas, Campinas, Brazil, (2)Medical Mycology Research Center, Chiba University, Chiba, Japan, (3)Clinical Pathology, University of Campinas, Campinas, Brazil

Disclosures:

L. Sturaro, None

T. Gonoi, None

K. Sakae, None

A. Busso-Lopes, None

Y. Mikami, None

P. Trabasso, None

C. Tararam, None

L. Lyra, None

C. E. Levy, None

H. Taguchi, None

A. Schreiber, None

K. Kamei, None

M. L. Moretti, None

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