背景:囊性纤维化(CF)肺部感染中真菌的患病率知之甚少,研究集中在成年患者身上。我们使用支气管肺泡灌洗(BAL)和诱导痰(IS)样本捕获多个肺壁ni,研究了CF患儿的真菌多样性。
方法:对作为CF-SpIT研究的一部分收集的23名儿童的25组匹配的BAL-IS样本进行真菌ITS2区域测序和分子分枝杆菌多样性分析(UKCRN14615;ISRCTNR12473810)。
结果:在所有样本中均检测到曲霉属和念珠菌属,是最丰富和最普遍的属,其次是Dipodascus,LecanicilliumandSimpliicillium.推定CF病原体Exophiala,Lomentospora和Scedosporium被鉴定为100%的可变丰度,64%,和24%的样本集,分别。在超过50%的队列中,常规培养微生物学无法准确诊断出高相对丰度(≥40%)的真菌病原体。BAL和IS样本捕获的真菌群落在多样性和组成上相似,除了白色念珠菌在IS样本中显著增加。个体之间的呼吸道分枝杆菌群差异很大,25个样本集中只有13个含有优势真菌分类单元。在11/25BAL样品组中,从不同的肺叶检测到不同的分枝杆菌群,观察到气道分隔。
结论:儿科分枝杆菌是多样化的,通过常规微生物学诊断复杂且不充分。在BAL和IS样本中发现了重叠的真菌群落,表明IS可以捕获与下气道相关的真菌属。下气道的分区为一致的分枝杆菌采样带来了困难。
BACKGROUND: The prevalence of fungi in cystic fibrosis (CF) lung infections is poorly understood and studies have focused on adult patients. We investigated the fungal diversity in children with CF using bronchoalveolar lavage (BAL) and induced sputum (IS) samples to capture multiple lung niches.
METHODS: Sequencing of the fungal ITS2 region and molecular mycobiota diversity analysis was performed on 25 matched sets of BAL-IS samples from 23 children collected as part of the CF-SpIT study (UKCRN14615; ISRCTNR12473810).
RESULTS: Aspergillus and Candida were detected in all samples and were the most abundant and prevalent genera, followed by Dipodascus, Lecanicillium and Simplicillium. The presumptive CF pathogens Exophiala, Lomentospora and Scedosporium were identified at variable abundances in 100 %, 64 %, and 24 % of sample sets, respectively. Fungal pathogens observed at high relative abundance (≥40 %) were not accurately diagnosed by routine culture microbiology in over 50 % of the cohort. The fungal communities captured by BAL and IS samples were similar in diversity and composition, with exception to C. albicans being significantly increased in IS samples. The respiratory mycobiota varied greatly between individuals, with only 13 of 25 sample sets containing a dominant fungal taxon. In 11/25 BAL sample sets, airway compartmentalisation was observed with diverse mycobiota detected from different lobes of the lung.
CONCLUSIONS: The paediatric mycobiota is diverse, complex and inadequately diagnosed by conventional microbiology. Overlapping fungal communities were identified in BAL and IS samples, showing that IS can capture fungal genera associated with the lower airway. Compartmentalisation of the lower airway presents difficulties for consistent mycobiota sampling.