Visible DNA Microarray System as an Adjunctive Molecular Test in Identification of Pathogenic Fungi Directly from a Blood Culture Bottle

Autor(es)

Sturaro, Lais Lovison ^[1] ; Gonoi, Tohru ^[2] ; Busso-Lopes, Ariane Fidelis ^[3] ; Tararam, Cibele Aparecida ^[1] ; Levy, Carlos Emilio ^[4] ; Lyra, Luzia ^[4] ; Trabasso, Plinio ^[1] ; Schreiber, Angelica Zaninelli ^[4] ; Kamei, Katsuhiko ^[2] ; Moretti, Maria Luiza ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Fac Med Sci, Dept Internal Med, Sao Paulo - Brazil

^[2] Chiba Univ, Med Mycol Res Ctr, Chiba - Japan

^[3] Brazilian Biosci Natl Lab, Sao Paulo - Brazil

^[4] Univ Estadual Campinas, Fac Med Sci, Dept Clin Pathol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Clinical Microbiology; v. 56, n. 5 MAY 2018.
• Citações Web of Science: 0

Resumo

A DNA microarray platform, based on the nucleotide sequences of the internal transcribed spacer regions (ITS1 and ITS2) of the rRNA gene, was developed to identify 32 fungal pathogens at the species level. The probe sequences were spotted onto polycarbonate slides with a mini-microarray printer, and after the hybridization, the results were visible with the naked eye. The performance of the microarray platform was evaluated against the commercial automated systems (Vitek 2 and BD Phoenix systems) and DNA sequencing (gold standard). A total of 461 blood culture bottles were tested: 127 positive for fungi, 302 positive for bacteria, and 32 that were negative. Once the microorganisms were identified by automated systems, fungal DNA was extracted directly from the blood culture bottles. The DNA products were tested using the microarray platform, and DNA sequencing was performed. The results of the microarray and DNA sequencing were concordant in 96.7% of cases, and the results from the automated systems and DNA sequencing were concordant in 98.4%. Of all the nucleotide sequences contained in the microarray platform, the microarray failed to identify four fungal isolates (one Candida parapsilosis, two Candida tropicalis, and one Cryptococcus neoformans). Of note, the microarray detected Candida krusei DNA in two blood cultures from the same patient, whereas the automated system was only positive for Enterococcus faecium. Our microarray system provided reliable and fast fungal identification compared to that from DNA sequencing and the automated systems. The simplicity of reading the results by the naked eye made this DNA platform a suitable method for fungal molecular diagnosis. (AU)

• Processo FAPESP: 12/51158-0 - Aplicação de novas tecnologias para o aprimoramento do diagnóstico e manejo das infeccções fúngicas em pacientes com AIDS e outras condições imunodepressoras
• Beneficiário: Maria Luiza Moretti
• Modalidade de apoio: Auxílio à Pesquisa - Regular