Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran.
Department Pediatrics, Ilam University of Medical Sciences, Ilam, Iran.
Microb Pathog. 2020 Jun;143:104115. doi: 10.1016/j.micpath.2020.104115. Epub 2020 Mar 3.
The high incidence of bacterial respiratory infections has led to a focus on evaluating the human respiratory microbiome. Studies based on culture-based and molecular methods have shown an increase in the bacterial community that includes the bacterial phyla Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria in the oropharynx of healthy individuals. Therefore, recognizing this microbial compound and subsequently identifying those carriers of specific pathogens can be of great help in predicting future infections and their control. In this prospective study, we sought to characterize the bacterial communities of the respiratory microbiome in healthy children aged between 3 and 6 years old by combining both cultural techniques and sequencing of the 16S rRNA gene. Seventy-seven oropharynx samples using Dacron swabs were collected from 77 healthy children in the kindergartens of Ilam, Iran. Bacterial identification was performed by phenotypic methods and in house developed PCR-based sequencing (the V1-V9 hypervariable region of the bacterial 16S ribosomal RNA gene). In total, 346 bacterial isolates were characterized based on phenotypic and sequencing-based molecular methods. The 3 most predominant phyla were Firmicutes (74%), Proteobacteria (22%), and Actinobacteria (4%). At the level of the genus, Staphylococci (coagulase-positive and coagulase-negative) and Streptococci were dominant. Also, the most commonly identified potentially pathogenic colonisers were S. aureus (75%), Enterobacteriaceae spp. (40.1%), and A. baumannii (15.6%). The present study identified 3 phyla and 9 family of bacteria in the oropharyngeal microbiome. Remarkably, the presence of potential pathogenic bacteria in the nasopharynx of healthy children can predispose them to infectious diseases, and also frequent exposure to human respiratory bacterial pathogens are further risk factors.
呼吸道细菌感染发病率高，促使人们开始关注人类呼吸道微生物组。基于培养和分子方法的研究表明，健康个体的口咽部细菌群落中厚壁菌门、拟杆菌门、放线菌门和变形菌门等细菌增多。因此，识别这种微生物组合，进而识别特定病原体的携带者，对于预测未来感染及其控制具有重要意义。在这项前瞻性研究中，我们试图通过结合培养技术和 16S rRNA 基因测序来描述 3 至 6 岁健康儿童的呼吸道微生物组的细菌群落。我们从伊朗 Ilam 市幼儿园的 77 名健康儿童中采集了 77 个咽拭子样本。采用表型方法和内部开发的基于 PCR 的测序（细菌 16S 核糖体 RNA 基因的 V1-V9 高变区）进行细菌鉴定。总共根据表型和基于测序的分子方法对 346 个细菌分离株进行了特征描述。最主要的 3 个菌门是厚壁菌门（74%）、变形菌门（22%）和放线菌门（4%）。在属水平上，葡萄球菌（凝固酶阳性和凝固酶阴性）和链球菌占优势。此外，最常鉴定出的潜在致病性定植菌是金黄色葡萄球菌（75%）、肠杆菌科（40.1%）和鲍曼不动杆菌（15.6%）。本研究在咽峡部微生物组中鉴定出 3 个菌门和 9 个细菌科。值得注意的是，健康儿童鼻咽部存在潜在的致病性细菌可能使他们易患传染病，而且频繁接触人类呼吸道细菌病原体也是进一步的风险因素。
