BACKGROUND Streptococcus pneumoniae is a significant global pathogen that colonises the nasopharynx of healthy children. Pneumococcal conjugate vaccines, which reduce nasopharyngeal colonisation of vaccine-type S. pneumoniae, may have broader effects on the nasopharyngeal microbiota; however, data are limited. In Fiji, nasopharyngeal carriage prevalence of S. pneumoniae and other colonising species differ between the two main ethnic groups. Here, we examined the association between the 7-valent pneumococcal conjugate vaccine (PCV7) and the nasopharyngeal microbiota of children in Fiji, including for each of the two main ethnic groups-indigenous Fijians (iTaukei) and Fijians of Indian descent (FID). METHOD The nasopharyngeal microbiota of 132 Fijian children was examined using nasopharyngeal swabs collected from 12-month-old iTaukei and FID children who were vaccinated (3 doses PCV7) or unvaccinated in infancy as part of a phase II randomised controlled trial. Microbiota composition was determined by sequencing the V4 region of the 16S rRNA gene. Species-specific carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus was determined using real-time quantitative PCR. Associations between microbiota composition and other host and environmental factors were considered in the analysis. RESULTS PCV7 had no overall impact on microbial diversity or composition. However, ethnic differences were observed in both diversity and composition with iTaukei children having higher relative abundance of Moraxella (p = 0.004) and Haemophilus (p = 0.004) and lower relative abundance of Staphylococcus (p = 0.026), Dolosigranulum (p = 0.004) and Corynebacterium (p = 0.003) compared with FID children. Further, when we stratified by ethnicity, associations with PCV7 could be detected: vaccinated iTaukei children had a lower relative abundance of Streptococcus and Haemophilus compared with unvaccinated iTaukei children (p = 0.022 and p = 0.043, respectively); and vaccinated FID children had a higher relative abundance of Dolosigranulum compared with unvaccinated FID children (p = 0.037). Children with symptoms of an upper respiratory tract infection (URTI) had a significantly different microbiota composition to children without symptoms. The microbiota composition of iTaukei children without URTI symptoms was most similar to the microbiota composition of FID children with URTI symptoms. CONCLUSIONS Associations between PCV7 and nasopharyngeal microbiota differed within each ethnic group. This study highlights the influence that ethnicity and URTIs have on nasopharyngeal microbiota.

中文翻译：

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肺炎球菌疫苗接种，种族与斐济儿童鼻咽微生物群之间的关联。

背景技术肺炎链球菌是定植在健康儿童鼻咽中的重要的全球病原体。减少疫苗型肺炎链球菌鼻咽定殖的肺炎球菌结合疫苗可能对鼻咽微生物群产生更广泛的影响。但是，数据是有限的。在斐济，两个主要种族之间的肺炎链球菌和其他定居物种的鼻咽运输率不同。在这里，我们检查了7价肺炎球菌结合疫苗（PCV7）与斐济儿童的鼻咽微生物群之间的关联，包括两个主要族群-土著斐济人（iTaukei）和印度裔斐济人（FID）。方法采用II期随机对照试验的一部分，从12个月大的iTaukei和FID儿童中收集的鼻咽拭子检查了132例斐济儿童的鼻咽菌群，这些儿童已接种疫苗（3剂PCV7剂量）或在婴儿期未接种疫苗。通过对16S rRNA基因的V4区域进行测序来确定微生物群的组成。使用实时定量PCR确定了肺炎链球菌，流感嗜血杆菌，卡他莫拉菌和金黄色葡萄球菌的物种特异性运输。分析中考虑了微生物群组成与其他宿主和环境因素之间的关联。结果PCV7对微生物的多样性或组成没有总体影响。然而，在iTaukei儿童中，莫拉氏菌（p = 0.004）和嗜血杆菌（p = 0.004）的相对丰度较高，葡萄球菌（p = 0.026），Dolosigranulum（p = 0.004）和棒状杆菌的相对丰度较低，在多样性和组成上都观察到种族差异。 （p = 0.003）与FID儿童相比。此外，当我们按种族分层时，可以检测到与PCV7的关联：与未接种疫苗的iTaukei儿童相比，接种iTaukei的儿童链球菌和嗜血杆菌的相对丰度较低（分别为p = 0.022和p = 0.043）；与未接种FID的儿童相比，接种FID的儿童的Dolosigranulum相对丰度更高（p = 0.037）。有上呼吸道感染（URTI）症状的儿童与没有症状的儿童相比，其菌群组成明显不同。没有URTI症状的iTaukei儿童的微生物群组成与具有URTI症状的FID儿童的微生物群组成最相似。结论在每个种族中，PCV7与鼻咽微生物群之间的关联各不相同。这项研究强调了种族和URTI对鼻咽微生物群的影响。