Bacterial Density, Serotype Distribution and Antibiotic Resistance of Pneumococcal Strains from the Nasopharynx of Peruvian Children Before and After Pneumococcal Conjugate Vaccine 7
Bacterial Density, Serotype Distribution and Antibiotic Resistance of Pneumococcal Strains from the Nasopharynx of Peruvian Children Before and After Pneumococcal Conjugate Vaccine 7
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DOI：
10.1097/inf.0000000000001030
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发表时间：
2016-04-01
影响因子：
3.6
通讯作者：
Vidal, Jorge E.
中科院分区：
文献类型：
--
作者：
Hanke, Christiane R.;Grijalva, Carlos G.;Vidal, Jorge E.
背景：肺炎球菌结合疫苗（PCV）减少了疫苗类型的鼻咽携带，但来自农村地区的数据很少。在引入 PCV7 两年后，我们调查了秘鲁安第斯山脉幼儿鼻咽部肺炎球菌菌株的细菌密度、血清型分布和抗生素耐药性。方法：从秘鲁队列的 125 名儿童中分离出肺炎球菌菌株，这些儿童于 2009 年进入研究，并在 2009 年和 2009 年随访期间在鼻咽部检测到肺炎球菌。 2011. 对菌株进行 Quellung 血清分型并测试抗生素敏感性。通过定量聚合酶链式反应测定细菌密度。结果：PCV7菌株的流行率从2009年的48%下降到2011年的28.8%，而非PCV7菌株的流行率从52%增加到71.2%（P = 0.002）。 2011 年，血清型 6C 的携带量增加了 3.5 倍（P = 0.026）。 PCV7 疫苗接种不会影响 PCV7 型定植儿童的肺炎球菌密度，但会增加非 PCV7 型定植儿童的肺炎球菌密度。引入疫苗后抗生素耐药性没有改变；菌株对四环素 (97.2%)、甲氧苄氨嘧啶-磺胺甲恶唑 (56.4%)、青霉素 (34%)、红霉素 (22.4%)、氯霉素 (18.8%) 和克林霉素 (12.4%) 不敏感。结论：PCV7 疫苗接种后观察到血清型替换，同时伴随着先前未识别的、增加的血清型替换。鼻咽密度。
Background: Pneumococcal conjugate vaccines (PCV) have decreased nasopharyngeal carriage of vaccine types but little data exist from rural areas. We investigated bacterial density, serotype distribution and antibiotic resistance of pneumococcal strains within the nasopharynx of young children in the Peruvian Andes, 2 years after PCV7 was introduced.Methods: Pneumococcal strains were isolated from a subset of 125 children from our Peruvian cohort, who entered the study in 2009 and had pneumococcus detected in the nasopharynx in both 2009 and during follow-up in 2011. Strains were Quellung serotyped and tested for susceptibility to antibiotics. Bacterial density was determined by quantitative polymerase chain reaction.Results: The prevalence of PCV7 strains decreased from 48% in 2009 to 28.8% in 2011, whereas non-PCV7 types increased from 52% to 71.2% (P = 0.002). There was a 3.5-fold increase in carriage of serotype 6C in 2011 (P = 0.026). Vaccination with PCV7 did not affect pneumococcal density in children colonized by a PCV7 type but did increase density in those colonized with a non-PCV7 type. Antibiotic resistance did not change after vaccine introduction; strains were nonsusceptible to tetracycline (97.2%), trimethoprim-sulfamethoxazole (56.4%), penicillin (34%), erythromycin (22.4%), chloramphenicol (18.8%) and clindamycin (12.4%).Conclusions: Serotype replacement was observed post-PCV7 vaccination with a concomitant, not previously recognized, increased nasopharyngeal density.