Affiliation:
1. South African Medical Research Council, Vaccines and Infectious Diseases Analytics Research Unit, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand
Abstract
Abstract
Background: Sensitive tools for detecting concurrent colonizing pneumococcal serotypes are needed for detailed evaluation of the direct and indirect impact of routine pneumococcal conjugate vaccine (PCV) immunization. Method: A high-throughput quantitative nanofluidic real-time PCR (Fluidigm) reaction-set was developed to detect and quantify 92 pneumococcal serotypes in archived clinical samples. Nasopharyngeal swabs collected in 2009-2011 from South African children ≤5years-old, previously serotyped with standard culture-based methods were used for comparison.
Results: The reaction-set within the Fluidigm® effectively amplified all targets with high efficiency (90-110%), reproducibility (R2≥0.98), and at low limit-of-detection (<102 CFU/ml). A blind analysis of 1973 nasopharyngeal swab samples showed diagnostic sensitivity >80% and specificity >95 compared with the referent standard, culture-based Quellung method. The Fluidigm method was able to serotype pneumococcal types with good discrimination compared with Quellung (ROC-AUC: >0.73).
Conclusion: The high-throughput nanofluidic real-time PCR method simultaneously detects 57 individual serotypes, and 35 serotypes within 16 serogroups in 96 samples (including controls), within a single qPCR run. This method can be used to evaluate the impact of current PCV formulations on vaccine-serotype and non-vaccine-serotype colonization, including detection of multiple concurrently colonizing serotypes.
Interpretation: The Fluidigm method can allow for monitoring of serotype-specific bacterial load, as well as emergence or ongoing transmission of minor or co-colonizing serotypes that may have invasive disease potential.
Publisher
Research Square Platform LLC
Reference53 articles.
1. Genetic analysis of the capsular biosynthetic locus from all 90 pneumococcal serotypes;Bentley SD;PLoS Genet,2006
2. Genetic relatedness of the Streptococcus pneumoniae capsular biosynthetic loci;Mavroidi A;J Bacteriol,2007
3. Ganaie F, Saad JS, McGee L, van Tonder AJ, Bentley SD, Lo SW, Gladstone RA, Turner P, Keenan JD, Breiman RF et al: A New Pneumococcal Capsule Type, 10D, is the 100th Serotype and Has a Large < em > cps Fragment from an Oral Streptococcus. mBio 2020, 11(3):e00937-00920.
4. Strong association between capsular type and virulence for mice among human isolates of Streptococcus pneumoniae;Briles DE;Infection and immunity,1992
5. Association of serotype with risk of death due to pneumococcal pneumonia: a meta-analysis;Weinberger DM;Clin Infect Dis,2010
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献