» Articles » PMID: 19202106

Production of a Unique Pneumococcal Capsule Serotype Belonging to Serogroup 6

Overview
Specialty Microbiology
Date 2009 Feb 10
PMID 19202106
Citations 27
Authors
Affiliations
Soon will be listed here.
Abstract

Serogroup 6 of Streptococcus pneumoniae contains three serotypes, named 6A, 6B and 6C, with highly homologous capsule gene loci. The 6A and 6B capsule gene loci consistently differ from each other by only one nucleotide in the wciP gene. The 6A capsule gene locus has a galactosyltransferase, which has been replaced with a glucosyltransferase in the 6C capsule gene locus. We considered that a new serotype named '6X1' would be possible if the galactosyltransferase of the 6B capsule gene locus is replaced with the glucosyltransferase of 6C. We demonstrate that this gene transfer yields a viable pneumococcal strain and that the capsular polysaccharide (PS) from this strain has the predicted chemical structure and serological similarity to the capsular PS of the 6B serotype. The new strain (i.e. serotype 6X1) is typed as 6B by the quellung reaction, but it can be distinguished from 6B strains with mAbs to 6B PS. Reexamination of 264 pneumococcal isolates that had been previously typed as 6B with classical typing methods revealed no isolates expressing serotype 6X1. Nevertheless, this study shows that this capsular PS is biochemically possible and could exist/emerge in nature.

Citing Articles

Update on the evolving landscape of pneumococcal capsule types: new discoveries and way forward.

Ganaie F, Beall B, Yu J, van der Linden M, McGee L, Satzke C Clin Microbiol Rev. 2025; 38(1):e0017524.

PMID: 39878373 PMC: 11905375. DOI: 10.1128/cmr.00175-24.


Serotypes and Vaccine Coverage of Colonization in the Nasopharynx of Thai Children in Congested Areas in Chiang Mai.

Wangirapan A, Ayuthaya S, Katip W, Kasatpibal N, Mektrirat R, Anukool U Pathogens. 2020; 9(12).

PMID: 33255981 PMC: 7761239. DOI: 10.3390/pathogens9120988.


Position of O-Acetylation within the Capsular Repeat Unit Impacts the Biological Properties of Pneumococcal Serotypes 33A and 33F.

Spencer B, Saad J, Shenoy A, Orihuela C, Nahm M Infect Immun. 2017; 85(7).

PMID: 28438972 PMC: 5478959. DOI: 10.1128/IAI.00132-17.


Pneumococcal Capsules and Their Types: Past, Present, and Future.

Geno K, Gilbert G, Song J, Skovsted I, Klugman K, Jones C Clin Microbiol Rev. 2015; 28(3):871-99.

PMID: 26085553 PMC: 4475641. DOI: 10.1128/CMR.00024-15.


Genetic, biochemical, and serological characterization of a new pneumococcal serotype, 6H, and generation of a pneumococcal strain producing three different capsular repeat units.

Park I, Geno K, Yu J, Oliver M, Kim K, Nahm M Clin Vaccine Immunol. 2015; 22(3):313-8.

PMID: 25589550 PMC: 4340893. DOI: 10.1128/CVI.00647-14.


References
1.
Sun Y, Hwang Y, Nahm M . Avidity, potency, and cross-reactivity of monoclonal antibodies to pneumococcal capsular polysaccharide serotype 6B. Infect Immun. 2000; 69(1):336-44. PMC: 97888. DOI: 10.1128/IAI.69.1.336-344.2001. View

2.
Hill P, Cheung Y, Akisanya A, Sankareh K, Lahai G, Greenwood B . Nasopharyngeal carriage of Streptococcus pneumoniae in Gambian infants: a longitudinal study. Clin Infect Dis. 2008; 46(6):807-14. DOI: 10.1086/528688. View

3.
Del Campo R, Morosini M, De la Pedrosa E, Fenoll A, Munoz-Almagro C, Maiz L . Population structure, antimicrobial resistance, and mutation frequencies of Streptococcus pneumoniae isolates from cystic fibrosis patients. J Clin Microbiol. 2005; 43(5):2207-14. PMC: 1153755. DOI: 10.1128/JCM.43.5.2207-2214.2005. View

4.
Park S, Moore M, Bruden D, Hyde T, Reasonover A, Harker-Jones M . Impact of conjugate vaccine on transmission of antimicrobial-resistant Streptococcus pneumoniae among Alaskan children. Pediatr Infect Dis J. 2008; 27(4):335-40. DOI: 10.1097/INF.0b013e318161434d. View

5.
Aanensen D, Mavroidi A, Bentley S, Reeves P, Spratt B . Predicted functions and linkage specificities of the products of the Streptococcus pneumoniae capsular biosynthetic loci. J Bacteriol. 2007; 189(21):7856-76. PMC: 2168755. DOI: 10.1128/JB.00837-07. View