Busser Felipe Delatorre, Coelho Vivian Caso, Fonseca Claudia de Abreu, Del Negro Gilda Maria Barbaro, Shikanai-Yasuda Maria Aparecida, Lopes Marta Heloisa, Magri Marcello Mihailenko Chaves, Freitas Vera Lucia Teixeira de
Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Laboratório de Investigação Médica em Imunologia (LIM 48), São Paulo, São Paulo, Brazil.
Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Laboratório de Investigação Médica em Micologia (LIM 53), São Paulo, São Paulo, Brazil.
Rev Inst Med Trop Sao Paulo. 2020 Feb 7;62:e9. doi: 10.1590/S1678-9946202062009. eCollection 2020.
Candidemia is a significant cause of bloodstream infections (BSI) in nosocomial settings. The identification of species can potentially improve the quality of care and decrease human mortality. Quantitative PCR (qPCR) was evaluated for Candida albicans detection using culture suspensions containing C. albicans , spiked human blood, the cloned qPCR target fragment (ITS2 region) and the results of these assays were compared. The assays showed a good detection limit: C. albicans DNA extracted from yeast (sensitivity 0.2 CFU/µL), spiked human blood (sensitivity 10 CFU/mL), and cloned fragment of ITS2 region (sensitivity 20 target copies/μL). The efficiency of ITS2 fragment-qPCR ranged from 89.67 to 97.07, and the linearity (R2) of the standard curve ranged from 0.992 to 0.999. The results showed that this ITS2-qPCR has a great potential as a molecular prototype model for the development of a test to be applied in clinical practice, greatly reducing the time of candidemia diagnosis, which is extremely important in this clinical setting.
念珠菌血症是医院环境中血流感染（BSI）的一个重要原因。菌种鉴定有可能提高护理质量并降低人类死亡率。使用含有白色念珠菌的培养悬液、加标的人血、克隆的qPCR靶片段（ITS2区域）对定量PCR（qPCR）检测白色念珠菌的性能进行了评估，并比较了这些检测的结果。这些检测显示出良好的检测限：从酵母中提取的白色念珠菌DNA（灵敏度0.2 CFU/µL）、加标的人血（灵敏度10 CFU/mL）以及ITS2区域的克隆片段（灵敏度20个靶拷贝/μL）。ITS2片段-qPCR的效率在89.67至97.07之间，标准曲线的线性度（R2）在0.992至0.999之间。结果表明，这种ITS2-qPCR作为一种分子原型模型，在开发可应用于临床实践的检测方法方面具有巨大潜力，可大大缩短念珠菌血症的诊断时间，这在这种临床环境中极其重要。
