[Impact of Streptococcuspneumoniae colonization in upper airway on the clinical manifestations of children with respiratory syncytial virus infection].

Objective: To investigate the effects of Streptococcuspneumoniae (Spn) colonization and the change of upper airway microbiome on the clinical manifestations in children with respiratory syncytial virus (RSV) infection. Methods: A retrospective cohort included 508 RSV-infected children with pneumonia and hospitalized in Respiratory Department of Children's Hospital of Chongqing Medical University from July 2009 to July 2018. A total of 508 cases of RSV-infected children (RSV non-sequencing group) were divided into 2 groups: children with Spn airway colonization (RSV+Spn group) and children without with Spn airway colonization (RSV group) according to the detection for virus and bacteria in nasopharyngeal aspirate, and these 2 groups were compared in terms of clinical manifestations by chi-square test in different age groups. In addition, in RSV pandemic season from November 2018 to February 2020, nasopharyngeal aspirates were collected from 20 children hospitalized in Respiratory Department of Children's Hospital of Chongqing Medical University and infected with RSV but without any positive detection of bacteria (RSV 16 S-sequencing group) and from children undergoing surgery without any sign of respiratory infection (control group). The difference of microbiome detected by 16 S RNA sequencing was compared using rank sum test between RSV 16 S-sequencing group and control group, and also between children with severe and mild pneumonia in RSV 16 S-sequencing group. Results: A total of 508 RSV non-sequencing group included 346 males and 162 females, and the visiting age was 6 (2, 12) months. RSV group included 443 cases and RSV+Spn group included 65 cases. In the study 244 cases were aged <6 months and 264 cases were aged ≥6 months. In children aged ≥6 months of RSV non-sequencing group, the proportion of cases presenting fever over 38 ℃ and cases with severe pneumonia in RSV+Spn group were higher than those in RSV group (53.2% (25/47) vs. 34.6% (72/217), 38.3% (18/47) vs. 21.2% (46/217), χ²=5.70,6.15, both P<0.05). RSV 16 S-sequencing group included 16 males and 4 females and the visiting age was 3.0 (1.9, 8.0) months. Airway microbiome diversity in RSV 16 S-sequencing group was lower than that in control group (alpha index: 0.93 (0.42, 2.51) vs. 3.05 (2.88, 3.61), U=60.00, P=0.001). Conclusions: RSV infection is associated with the changes of the upper airway microbiome. When the balance of airway microbiome is broken and the presence of the dominant colonization of Spn follows, it may aggravate the severity of RSV infection in children aged ≥6 months.目的： 探讨上呼吸道优势定植菌肺炎链球菌（Spn）以及呼吸道微生态改变对呼吸道合胞病毒（RSV）感染患儿临床表现及严重程度的影响。 方法： 回顾性收集2009年7月至2018年7月在重庆医科大学附属儿童医院呼吸科住院的508例RSV感染患儿（以下称RSV非微生物测序患儿）的临床资料。根据鼻咽抽吸物细菌培养及检验结果将患儿分为RSV感染不合并Spn定植组（简称RSV组）和RSV感染合并Spn定植组（简称RSV+Spn组），分别比较2组患儿在<6月龄和≥6月龄临床特征的差异，组间比较采用χ2检验。另外收集2018年11月至2020年2月RSV流行季节在重庆医科大学附属儿童医院呼吸科住院的RSV感染且鼻咽抽吸物无细菌检出的20例患儿的鼻咽抽吸物（简称RSV微生物测序组）资料，同时收集16例外科住院的无呼吸道感染的患儿鼻咽抽吸物作为对照组，通过Mann-Whitney U秩和检验分别比较2组患儿的呼吸道微生物多样性；根据重症肺炎的诊断标准，将RSV微生物测序组分为轻症肺炎组和重症肺炎组，通过秩和检验比较组间菌群组成。 结果： 508例RSV非微生物测序患儿中男346例、女162例，就诊年龄为6（2，12）月龄。RSV组患儿443例、RSV+Spn组患儿65例。<6月龄244例、≥6月龄264例。≥6月龄的RSV+Spn组患儿发热>38 ℃及重症肺炎的患儿均高于RSV组［53.2%（25/47）比34.6%（75/217）、38.3%（18/47）比21.2%（46/217），χ²=5.70、6.15，均P<0.05］。20例RSV微生物测序组患儿中男16例、女4例，就诊年龄为3.0（1.9，8.0）月龄，重症肺炎组8例，轻症肺炎组12例，2组患儿呼吸道微生物组成中差异无统计学意义（均P>0.05）。RSV微生物测序组患儿上呼吸道微生态多样性低于对照组［alpha多样性指数：0.93（0.42，2.51）比3.05（2.88，3.61），U=60.00，P=0.001］。 结论： RSV感染能够引起呼吸道微生态的菌落组成改变，当呼吸道微生态的平衡被破坏，优势定植菌Spn出现时，会加重≥6月龄的RSV感染患儿的病情。.