Streptococcus pneumoniaeserotype 33G: genetic, serological, and structural analysis of a new capsule type

• DOI: 10.1101/2023.09.11.556596
• Publication Date: 2023-09-12T04:55:12Z
• Authors: Sam Manna; Joel P. Werren; Belinda D. Ortika; Barbara Bellich; Casey L. Pell; Elissavet Nikolaou; Ilche Gjuroski; Stephanie Lo; Jason Hinds; Odgerel Tundev; Eileen M. Dunne; Bradford D. Gessner; Stephen D. Bentley; Fiona M. Russell; E. Kim Mulholland; Tuya Mungun; Claire von Mollen...; Paul V. Licciardi; Paola Cescutti; Neil Ravenscroft; Markus Hilty; Catherine Satzke
• Keywords: Bacterial capsule; Multilocus sequence typing

ABSTRACT Streptococcus pneumoniae (the pneumococcus) is a human pathogen responsible for spectrum of diseases such as pneumonia, sepsis, and meningitis. The capsule the major pneumococcal virulence factor encoded by capsular polysaccharide ( cps ) locus, recombination hot spot that has resulted in over 100 distinct types (serotypes) identified to date. Recently, 33X (also known 10X) was proposed putative novel serotype, but structure had not been elucidated. Here, we provide an in-depth investigation 33X, demonstrating it new serotype. In this study, screened 12,850 nasopharyngeal swabs from both healthy children pneumonia patients (adults children) Mongolia collected between 2015-2022. We 20 isolates. Using whole genome sequencing, found locus chimera genes serogroups 35, 10 33, well other Streptococcal species. Serotyping pneumococci Quellung reaction revealed unique serological profile, typing 10B 33B. Competitive ELISAs confirmed antibodies were generated mice directed against inhibited or Lastly, elucidation serotypes, consisting O-acetylated hexasaccharide repeat unit →5)-β-Gal f -(1→3)-β-Glc p -(1→5)-β-Gal 2Ac-(1→3)-β-Gal NAc-(1→3)-α-Gal -(1→4)-Rib-ol-(5→P→. Therefore, meets requisite genetic, serological, biochemical criteria be designated which have named 33G. IMPORTANCE bacterial with greatest burden disease Asia Africa. biological relevance factor, public health importance target currently licensed vaccines. These vaccines limited valency, covering up 23 >100 higher valency development. characterized detected serotype 33G (n=20) adults hospitalized Mongolia. show properties differs existing satisfying Future studies should focus on geographical distribution any changes prevalence following vaccine introduction.