利用时间质谱检出312例6月龄内健康婴儿鼻咽部微生态菌群的分布特征

目的 利用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术研究济南地区6月龄内健康婴儿鼻咽部微生态菌群分布特征,为鼻咽部微生态研究提供样本库信息。 方法 采集2019年11月至2020年4月济南地区312例6月龄内健康婴儿鼻咽拭子,增菌后,分离培养获得纯菌株;利用MALDI-TOF MS技术鉴定分离株到种置信水平;312例婴儿分为月龄≤2组、3月龄组、4月龄组和5月龄组,组间比较采用SPSS 22.0统计学软件,卡方或Fisher确切概率法统计分析。 结果 312例健康婴儿鼻咽拭子获得纯菌株741株,分属于25个属74种细菌。优势菌属为葡萄球菌属(31.6%)、棒杆菌属(30.8%)、链球菌属(18.9%)、莫拉菌属(8.6%)和狡诈球菌属(2.0%)。同时发现一些不常见菌种,例如缺陷乏氧菌、放射根瘤菌等。金黄色葡萄球菌检出率男婴(40.5%)高于女婴(26.4%),接近棒杆菌女婴(42.4%)高于男婴(27.4%)。4个年龄组中,假白喉棒杆菌检出率依次升高(10.8%、17.7%、18.9%、46.7%);肺炎链球菌检出率依次升高(2.2%、2.3%、4.1%、20.0%)。 结论 济南地区健康6月龄内婴儿鼻咽部微生态菌群以优势菌为主呈现多样化,MALDI-TOF MS是鉴定常见和不常见微生物菌种的快速、高通量技术手段。本研究可为济南地区儿童鼻咽部微生态研究提供有价值的样本库资料。

Distribution characteristics of nasopharyngeal microbiota of 312 healthy infants under 6 months of age detected by MALDI-TOF MS

Objective To explore the distribution characteristics of nasopharyngeal microflora in healthy infants under 6 months of age using matrix-assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS)so as to provide sample bank information for nasopharyngeal microecology research. Methods Nasopharyngeal swabs were collected from 312 healthy infants during Nov. 2019 and April 2020 in Jinan. The pure strains were obtained after culturing and isolating. The bacterial strains were identified by MALDI-TOF MS to the species-level. The infants were divided into four age groups(≤ 2 months, 3 months group, 4 months group and 5 months group). SPSS 22.0 software was used for chi-square test or Fisher exact test between groups. Results A total of 741 bacterial strains were isolated, including 74 species of 25 genera of bacteria. The dominant genera were Staphylococcus(31.6%), Corynebacterium(30.8%), Streptococcus(18.9%), Moraxella(8.6%)and Dolosicoccus(2.0%). Some uncommon bacteria were also found, such as Abiotrophia defectiva, Rhizobium radiobacter, et al. The detection rate of Staphylococcus aureus was higher in male infants(40.5%)than in female infants(26.4%), while the detection rate of Corynebacterium propinquum was higher in female infants(42.4%)than in male infants(27.4%). In the four age groups, the detection rate of Corynebacterium pseudodiphtheriticum was increased successively(10.8%, 17.7%, 18.9% and 46.7%), as the same for Streptococcus pneumoniae(2.2%, 2.3%, 4.1% and 20.0%). Conclusion The diversity is mainly characterized by dominant bacteria in nasopharyngeal microflora for healthy infants under 6 months of age in Jinan, China. MALDI-TOF MS is a rapid and high-throughput technique for identifying common and uncommon bacterial species. The results can provide valuable reference for the study of nasopharyngeal microecology of children in Jinan.