Vaccinology Theme, Medical Research Council Unit, Banjul, The Gambia.
PLoS One. 2013 Sep 23;8(9):e75558. doi: 10.1371/journal.pone.0075558. eCollection 2013.
CRM- based pneumococcal conjugate vaccines generally have little impact on the overall prevalence of pneumococcal carriage because of serotype replacement. In contrast, protein vaccines could substantially reduce the overall prevalence of pneumococcal carriage with potential microbiological and clinical consequences. Therefore, trials of pneumococcal protein vaccines need to evaluate their impact on carriage of other potentially pathogenic bacteria in addition to the pneumococcus.
As a prelude to a trial of an investigational pneumococcal vaccine containing pneumococcal polysaccharide conjugates and pneumococcal proteins, the prevalence of carriage of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella species and Staphylococcus aureus in the nasopharynx of 1030 Gambian infants (median age 35 weeks) was determined. An oropharyngeal swab was obtained at the same time from the first 371 infants enrolled. Standard microbiological techniques were used to evaluate the bacterial flora of the pharynx and to compare that found in the oropharynx and in the nasopharynx.
The overall pneumococcal carriage rate was high. Isolation rates of S. pneumoniae and Moraxella species were significantly higher using nasopharyngeal rather than oropharyngeal swabs (76.1% [95% CI 73.4%,78.7%] vs. 21.3% [95% CI 17.2%,25.8%] and 48.9% [95% CI 45.8%, 52.0%] vs. 20.5% % [95% CI 16.5%,25.0%] respectively). In contrast, S. aureus and H. influenzae were isolated more frequently from oropharyngeal than from nasopharyngeal swabs (65.0% [95% CI 59.9%, 69.8%] vs. 33.6% [95% CI 30.7%, 36.5%] and 31.8% [95% CI 16.5%, 25.0%] vs. 22.4% [95% CI 19.9%, 25.1%] respectively). No group A β haemolytic streptococci were isolated.
Collection of an oropharyngeal swab in addition to a nasopharyngeal swab will provide little additional information on the impact of a novel pneumococcal vaccine on pneumococcal carriage but it might provide additional, valuable information on the impact of the vaccine on the overall microbiota of the pharynx.
基于 CRM 的肺炎球菌结合疫苗通常对肺炎球菌携带的总体流行率影响不大，因为存在血清型替代现象。相比之下，蛋白疫苗可实质性降低肺炎球菌携带的总体流行率，从而带来潜在的微生物学和临床影响。因此，肺炎球菌蛋白疫苗的试验需要评估其对除肺炎球菌以外的其他潜在致病细菌携带的影响。
在一项含有肺炎球菌多糖结合物和肺炎球菌蛋白的试验性肺炎球菌疫苗的试验之前，我们确定了 1030 名冈比亚婴儿（中位年龄 35 周）鼻咽部的肺炎链球菌、流感嗜血杆菌、莫拉菌属和金黄色葡萄球菌携带率。前 371 名入组婴儿同时获得了咽拭子。采用标准微生物学技术评估了咽峡部细菌菌群，并比较了鼻咽部和口咽部的细菌菌群。
总体上肺炎球菌携带率很高。使用鼻咽拭子而非口咽拭子时，分离出的肺炎链球菌和莫拉菌属的比例明显更高（76.1%[95%CI 73.4%，78.7%]比 21.3%[95%CI 17.2%，25.8%]和 48.9%[95%CI 45.8%，52.0%]比 20.5%[95%CI 16.5%，25.0%]）。相比之下，金黄色葡萄球菌和流感嗜血杆菌更常从口咽拭子中分离出（65.0%[95%CI 59.9%，69.8%]比 33.6%[95%CI 30.7%，36.5%]和 31.8%[95%CI 16.5%，25.0%]比 22.4%[95%CI 19.9%，25.1%]）。未分离出 A 组β溶血性链球菌。
除鼻咽拭子外，再采集口咽拭子，对新型肺炎球菌疫苗对肺炎球菌携带的影响不会提供更多的信息，但可能会提供关于疫苗对咽峡部整体菌群影响的额外、有价值的信息。
