Ghods Nayereh, Falahati Mehraban, Roudbary Maryam, Farahyar Shirin, Shamaei Masoud, Pourabdollah Mahin, Seif Farhad
Iran University of Medical Sciences, School of Medicine, Department of Medical Mycology and Parasitology, Tehran, Iran.
Iran University of Medical Sciences, School of Medicine, Department of Medical Mycology and Parasitology, Tehran, Iran.
Braz J Microbiol. 2018 Jul-Sep;49(3):668-674. doi: 10.1016/j.bjm.2017.10.003. Epub 2018 Feb 3.
The virulence genes in invasive aspergillosis (IA) have not been analyzed adequately. The present study was designed to evaluate the expression of gpaB and sidA genes, which are important virulence genes in Aspergillus spp. from bronchoalveolar lavage (BAL) samples. Direct examination and culture on Czapek Agar and Sabouraud Dextrose Agar media were performed for 600 BAL specimens isolated from patients with possible aspergillosis. A Galactomannan ELISA assay was also carried out. The expression levels of the gpaB and sidA genes in isolates were analyzed using quantitative real-time PCR (qRT-PCR). We identified 2 species, including Aspergillus flavus (A. flavus) and Aspergillus fumigatus (A. fumigatus) in 25 positive samples for invasive aspergillosis as validated using GM-ELISA. A. flavus is the main pathogen threatening transplant recipients and cancer patients worldwide. In this study, A. flavus had low levels of the gpaB gene expression compared to A. fumigatus (p=0.006). The highest sidA expression was detected in transplant recipients (p=0.05). There was no significant correlation between sidA expression and underlying disease (p=0.15). The sidA and gpaB gene expression patterns may provide evidence that these virulence genes play important roles in the pathogenicity of Aspergillus isolates; however, there are several regulatory genes responsible for the unexpressed sidA and gpaB genes in the isolates.
侵袭性曲霉病（IA）中的毒力基因尚未得到充分分析。本研究旨在评估gpaB和sidA基因的表达，这两个基因是曲霉属中重要的毒力基因，来自支气管肺泡灌洗（BAL）样本。对从可能患有曲霉病的患者中分离出的600份BAL标本进行了直接检查，并在察氏琼脂和沙氏葡萄糖琼脂培养基上进行培养。还进行了半乳甘露聚糖酶联免疫吸附测定（Galactomannan ELISA assay）。使用定量实时聚合酶链反应（qRT-PCR）分析分离株中gpaB和sidA基因的表达水平。我们在25份侵袭性曲霉病阳性样本中鉴定出2个菌种，包括黄曲霉（A. flavus）和烟曲霉（A. fumigatus），这通过GM-ELISA得到了验证。黄曲霉是全球范围内威胁移植受者和癌症患者的主要病原体。在本研究中，与烟曲霉相比，黄曲霉的gpaB基因表达水平较低（p = 0.006）。在移植受者中检测到sidA的最高表达（p = 0.05）。sidA表达与基础疾病之间无显著相关性（p = 0.15）。sidA和gpaB基因的表达模式可能提供证据表明这些毒力基因在曲霉分离株的致病性中起重要作用；然而，在分离株中有几个调控基因负责未表达的sidA和gpaB基因。
