Genetic diversity of PspA types among nasopharyngeal isolates collected during an ongoing surveillance study of children in Brazil
Genetic diversity of PspA types among nasopharyngeal isolates collected during an ongoing surveillance study of children in Brazil
复制标题
DOI：
10.1128/jcm.00156-06
复制
发表时间：
2006-08-01
影响因子：
9.4
通讯作者：
Sgambatti de Andrade, Ana Lucia S.
中科院分区：
文献类型：
--
作者：
Pimenta, Fabiana Cristina;Ribeiro-Dias, Fatima;Sgambatti de Andrade, Ana Lucia S.
肺炎球菌表面蛋白A（PspA）由于其非型别依赖性的保护性免疫而被认为是人类疫苗的潜在候选者。鼻咽（NP）肺炎球菌定植在婴儿中非常普遍，并且先于侵袭性疾病。因此，预防NP定植可能会减少儿童肺炎球菌疾病的负担。关于人类肺炎球菌携带PspA的信息很少。我们研究了在一项正在进行的儿童肺炎球菌监测研究中获得的NP分离株PspA的遗传多样性。研究了183个社区获得性肺炎链球菌NP分离株的PspA家族和分支，这些分离株来自健康儿童（n = 97）和患有呼吸道感染（n = 48）、肺炎（n = 33）或脑膜炎（n = 5）的儿童。总体而言，79.8%（n = 146）的肺炎球菌分离株被归类为PspA家族1（35.5%）和家族2（44.3%），而20.2%的分离株无法分型。根据儿童的临床状况，PspA家族和分支的分布没有显著差异。比较NP菌株的PspA分支定义区域的氨基酸序列与24种侵袭性参考菌株（GenBank）之间的遗传关系的树状图紧密地再现了先前报道的肺炎球菌侵袭性菌株的家族和分支的概况。这些发现加强了这样一种观点，即使用PspA作为疫苗抗原可以保护儿童免受携带以及侵袭性肺炎球菌疾病的影响。
Pneumococcal surface protein A (PspA) has been considered a potential candidate for human vaccines because of its serotype-independent protective immunity. Nasopharyngeal (NP) pneumococcal colonization is highly prevalent in infants and precedes the invasive disease. Thus, prevention of NP colonization may reduce the burden of pneumococcal disease in children. Scarce information focusing on PspA from pneumococcal carriage in humans is available. We examined the genetic diversity of PspA from NP isolates obtained during an ongoing pneumococcal surveillance study with children. PspA families and clades of 183 community-acquired Streptococcus pneumoniae NP isolates from healthy children (n = 97) and children with respiratory tract infections (n = 48), pneumonia (n = 33), or meningitis (n = 5) were investigated. Overall, 79.8% (n = 146) of the pneumococcal isolates were classified as PspA family 1 (35.5%) and family 2 (44.3%), whereas 20.2% of the isolates could not be typed. The distribution of PspA families and clades did not differ significantly according to the clinical status of the children. A dendrogram comparing the genetic relationship between the amino acid sequences of the clade-defining region of PspA from NP strains together with 24 invasive reference strains (GenBank) closely reproduced the profile of the families and clades previously reported for pneumococcal invasive strains. These findings strengthen the idea that the use of PspA as a vaccine antigen may protect children against carriage as well as invasive pneumococcal disease.