Carried Pneumococci in Massachusetts Children
- 1 April 2011
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in The Pediatric Infectious Disease Journal
- Vol. 30 (4), 302-308
- https://doi.org/10.1097/inf.0b013e318201a154
Abstract
Background: Vaccination against 7 serotypes of Streptococcus pneumoniae has led to the near extinction of vaccine serotypes in both disease and asymptomatic carriage. In carriage, vaccine serotypes have been replaced by nonvaccine serotypes. Methods: We used multilocus sequence typing to analyze a sample of 294 isolates of S. pneumoniae carried by Massachusetts children (aged, 3 months–7 years) and examine the results for serotype switching and association with antimicrobial resistance. Results: Eighty-six distinct sequence types (STs) were found, 10 of which exhibited a serotype other than that which would be expected from previous carriage samples. We interpret this as evidence of past or recent serotype switching. Switched variants include ST 320, which is a common and increasing source of multidrug resistance in this community. Switching events within serogroups were more common than expected by chance (P = 0.043 by a Monte Carlo approach). Using multilocus sequence typing data and eBURST analysis, we also describe clonal dynamics within the important replacement serotypes 19A, 15B/C, 35B, and the recently described 6C. Conclusions: Some strains generated by serotype switching are increasingly important parts of the carriage population. In the case of 19A, it appears that the majority of increase is due to ST 320, a recently reported switched variant. This may have consequences for the STs causing invasive pneumococcal disease.Keywords
This publication has 26 references indexed in Scilit:
- Impact of a Pneumococcal Conjugate Vaccination Program on Carriage among Children in NorwayClinical and Vaccine Immunology, 2010
- Continued Impact of Pneumococcal Conjugate Vaccine on Carriage in Young ChildrenPublished by American Academy of Pediatrics (AAP) ,2009
- Increase in the Prevalence of the Newly Discovered Pneumococcal Serotype 6C in the Nasopharynx after Introduction of Pneumococcal Conjugate VaccineThe Journal of Infectious Diseases, 2009
- Population Snapshot of EmergentStreptococcus pneumoniaeSerotype 19A in the United States, 2005The Journal of Infectious Diseases, 2008
- Vaccine Escape Recombinants Emerge after Pneumococcal Vaccination in the United StatesPLoS Pathogens, 2007
- MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) Software Version 4.0Molecular Biology and Evolution, 2007
- Discovery of a New Capsular Serotype (6C) within Serogroup 6 ofStreptococcus pneumoniaeJournal of Clinical Microbiology, 2007
- Diversity and Antibiotic Resistance among Nonvaccine Serotypes ofStreptococcus pneumoniaeCarriage Isolates in the Post–Heptavalent Conjugate Vaccine EraThe Journal of Infectious Diseases, 2007
- Genetic Analysis of the Capsular Biosynthetic Locus from All 90 Pneumococcal SerotypesPLoS Genetics, 2006
- A multilocus sequence typing scheme for Streptococcus pneumoniae: identification of clones associated with serious invasive diseaseMicrobiology, 1998