Molecular Microbiology Department, Hospital Universitari Sant Joan de Déu, Passeig Sant Joan de Déu, 2, 08950, Esplugues de Llobregat, Barcelona, Spain.
Eur J Clin Microbiol Infect Dis. 2012 Jul;31(7):1487-95. doi: 10.1007/s10096-011-1468-7. Epub 2011 Nov 4.
Serotype 3 is one of the most often detected pneumococcal serotypes in adults and it is associated with serious disease. In contrast, the isolation of serotype 3 by bacterial culture is unusual in children with invasive pneumococcal disease (IPD). The purpose of this study was to learn the serotype distribution of IPD, including culture-negative episodes, by using molecular methods in normal sterile samples. We studied all children<5 years of age with IPD admitted to two paediatric hospitals in Catalonia, Spain, from 2007 to 2009. A sequential real-time polymerase chain reaction (PCR) approach was added to routine methods for the detection and serotyping of pneumococcal infection. Among 257 episodes (219 pneumonia, 27 meningitis, six bacteraemia and five others), 33.5% were identified by culture and the rest, 66.5%, were detected exclusively by real-time PCR. The most common serotypes detected by culture were serotypes 1 (26.7%) and 19A (25.6%), and by real-time PCR, serotypes 1 (19.8%) and 3 (18.1%). Theoretical coverage rates by the PCV7, PCV10 and PCV13 vaccines were 10.5, 52.3 and 87.2%, respectively, for those episodes identified by culture, compared to 5.3, 31.6 and 60.2% for those identified only by real-time PCR. Multiplex real-time PCR has been shown to be useful for surveillance studies of IPD. Serotype 3 is underdiagnosed by culture and is important in paediatric IPD.
血清型 3 是成人中最常检测到的肺炎球菌血清型之一，与严重疾病相关。相比之下，在患有侵袭性肺炎球菌病（IPD）的儿童中，通过细菌培养分离血清型 3 并不常见。本研究的目的是使用分子方法在正常无菌样本中了解包括培养阴性病例在内的 IPD 的血清型分布。我们研究了 2007 年至 2009 年期间在西班牙加泰罗尼亚的两家儿科医院收治的所有<5 岁的 IPD 患儿。在常规方法的基础上，我们增加了顺序实时聚合酶链反应（PCR）方法，用于检测和血清型鉴定肺炎球菌感染。在 257 例（219 例肺炎、27 例脑膜炎、6 例菌血症和 5 例其他病例）中，33.5% 通过培养鉴定，其余 66.5% 通过实时 PCR 独家检测。通过培养鉴定的最常见血清型为 1 型（26.7%）和 19A 型（25.6%），通过实时 PCR 鉴定的最常见血清型为 1 型（19.8%）和 3 型（18.1%）。通过培养鉴定的病例，PCV7、PCV10 和 PCV13 疫苗的理论覆盖率分别为 10.5%、52.3%和 87.2%，而仅通过实时 PCR 鉴定的病例的理论覆盖率分别为 5.3%、31.6%和 60.2%。多重实时 PCR 已被证明对 IPD 的监测研究有用。血清型 3 通过培养被低估，在儿科 IPD 中很重要。
