Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
Sci Rep. 2020 May 20;10(1):8373. doi: 10.1038/s41598-020-65399-x.
Streptococcus pneumoniae (pneumococcus) is a leading cause of infections worldwide. Disease is preceded by asymptomatic colonization of the upper respiratory tract. Classical culture-based methods (CCBM) suggest that colonization in the elderly is <5%. Recently, use of qPCR has challenged these observations. We estimated pneumococcal carriage prevalence and serotypes among Portuguese elderly using qPCR and compared results with those obtained by CCBM. Nasopharyngeal and oropharyngeal paired samples (599 each) of individuals over 60 years living in nursing (n = 299) or family (n = 300) homes were screened for the presence of pneumococci by qPCR targeting lytA and piaB. Positive samples were molecular serotyped. Use of qPCR improved detection of pneumococci in oropharyngeal samples compared to CCBM: from 0.7% to 10.4% (p < 0.001) in the nursing home collection, and from 0.3% to 5.0% (p < 0.001) in the family home collection. No significant differences were observed between both methods in nasopharyngeal samples (5.4% vs. 5.4% in the nursing homes; and 4.3% vs. 4.7% in the family homes). Twenty-one serotypes/serogroups were detected by qPCR compared to 14 by CCBM. In conclusion, use of qPCR suggests that pneumococcal carriage in Portuguese elderly is approximately 10%, and unveiled a large pool of serotypes. These results are important to understand progression to disease and impact of pneumococcal vaccines in the elderly.
肺炎链球菌（肺炎球菌）是全球感染的主要原因。疾病以前在上呼吸道无症状定植。基于经典培养的方法（CCBM）表明，老年人中的定植率<5%。最近，qPCR 的使用对这些观察结果提出了挑战。我们使用 qPCR 估计了葡萄牙老年人的肺炎球菌携带率和血清型，并将结果与 CCBM 获得的结果进行了比较。对居住在养老院（n = 299）或家庭（n = 300）中的 60 岁以上个体的鼻咽和口咽配对样本（各 599 个）进行 qPCR 检测，以检测肺炎球菌 lytA 和 piaB 的存在。对阳性样本进行分子血清型鉴定。与 CCBM 相比，qPCR 提高了口咽样本中肺炎球菌的检测率：在养老院采集样本中，从 0.7%提高到 10.4%（p<0.001），在家庭采集样本中，从 0.3%提高到 5.0%（p<0.001）。在鼻咽样本中，两种方法之间没有观察到显著差异（养老院中为 5.4%与 5.4%；家庭中为 4.3%与 4.7%）。通过 qPCR 检测到 21 种血清型/血清群，而通过 CCBM 检测到 14 种血清型/血清群。总之，qPCR 的使用表明，葡萄牙老年人的肺炎球菌携带率约为 10%，并揭示了大量的血清型。这些结果对于了解疾病进展和肺炎球菌疫苗对老年人的影响非常重要。
