Streptococcus mitis Expressing Pneumococcal Serotype 1 Capsule

• Type of Material: Article
• Authors: Fernanda C. Lessa, Centers for Disease Control and Prevention; Jennifer Milucky, Centers for Disease Control and Prevention; Nadine Rouphael, Emory University; Nancy M. Bennett, University of Rochester; H. Keipp Talbot, Vanderbilt University; Lee H. Harrison, Johns Hopkins Bloomberg School of Public Health; Monica Farley, Emory University; Jeremy Walston, Johns Hopkins University; Fabiana Pimenta, Centers for Disease Control and Prevention; Robert E. Gertz, Centers for Disease Control and Prevention; Gowrisankar Rajam, Centers for Disease Control and Prevention; Maria da Gloria Carvalho, Centers for Disease Control and Prevention; Bernard Beall, Centers for Disease Control and Prevention; Cynthia G. Whitney, Centers for Disease Control and Prevention
• Language: English
• Date: 2018-12-19
• Publisher: Nature Research (part of Springer Nature): Fully open access journals
• Publication Version: Final Published Version
• Copyright Statement: © 2018, The Author(s).
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1038/s41598-018-35921-3
• Title of Journal or Parent Work: Scientific Reports
• ISSN: 2045-2322
• Volume: 8
• Issue: 1
• Start Page: 17959
• End Page: 17959
• Grant/Funding Information: This work was funded by the Emerging Infections Program (EIP) Cooperative Agreement between the four EIP sites and the Centers for Disease Control and Prevention (Grant# CDC-RFA-CK17-1701).
• Keywords: CONJUGATE VACCINE; PNEUMONIAE; ASSAY; DISEASE; Science & Technology - Other Topics; ADULTS; CHILDREN; IDENTIFICATION; MENINGITIS; Multidisciplinary Sciences; LYTA; Science & Technology; IMPACT
• Research Categories: Health Sciences, Public Health; Health Sciences, General

Abstract

Streptococcus pneumoniae’s polysaccharide capsule is an important virulence factor; vaccine-induced immunity to specific capsular polysaccharide effectively prevents disease. Serotype 1 S. pneumoniae is rarely found in healthy persons, but is highly invasive and a common cause of meningitis outbreaks and invasive disease outside of the United States. Here we show that genes for polysaccharide capsule similar to those expressed by pneumococci were commonly detected by polymerase chain reaction among upper respiratory tract samples from older US adults not carrying pneumococci. Serotype 1-specific genes were predominantly detected. In five oropharyngeal samples tested, serotype 1 gene belonging to S. mitis expressed capsules immunologically indistinct from pneumococcal capsules. Whole genome sequencing revealed three distinct S. mitis clones, each representing a cps1 operon highly similar to the pneumococcal cps1 reference operon. These findings raise important questions about the contribution of commensal streptococci to natural immunity against pneumococci, a leading cause of mortality worldwide.