The capsular polysaccharide elaborated by Streptococcus pneumoniae type 7B is composed of the following heptasaccharide repeating-units. [formula: see text] The identities and modes of linkage of the constituents were established using sugar, methylation, and phosphorus analysis, together with 1D- and 2D-n.m.r. spectroscopy. The sequence was established from inter-residue n.O.e. data. The structure was corroborated by n.m.r. spectroscopy, f.a.b.-m.s., and methylation analysis of the oligosaccharides isolated after partial acid hydrolysis of the polysaccharide with aqueous 48% hydrogen fluoride. It is suggested that the structural basis for the common antigenic formula in the group 7 serotypes of S. pneumoniae is the disaccharide element alpha-D-GlcpNAc-(1----2)-alpha-L-Rhap-(1----.
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http://dx.doi.org/10.1016/0008-6215(91)84127-z | DOI Listing |
J Infect
January 2025
Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria. Electronic address:
Objectives: There is conflicting evidence as to whether the combined administration of two vaccines can lead to poorer immunogenicity and reactogenicity. The co-administration of the Omicron-adapted COVID-19 vaccine from Novavax (NVX-CoV2601) and a 20-valent pneumococcal conjugate vaccine (PCV20) has not been previously investigated.
Methods: In this randomised, double-blind, placebo-controlled, non-inferiority trial, immunocompetent participants aged ≥60 years were randomised in a 1:1:1:1 ratio to four groups: NVX-CoV2601 plus PCV20 (combination group); NVX-CoV2601 plus placebo (NVX-only group); PCV20 plus placebo (PCV20-only group); or placebo plus placebo (placebo group).
Elife
January 2025
Laboratory of Molecular Microbiology, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
The type VI secretion system (T6SS) is a sophisticated, contact-dependent nanomachine involved in interbacterial competition. To function effectively, the T6SS must penetrate the membranes of both attacker and target bacteria. Structures associated with the cell envelope, like polysaccharides chains, can therefore introduce spatial separation and steric hindrance, potentially affecting the efficacy of the T6SS.
View Article and Find Full Text PDFNat Commun
December 2024
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
The genomes of human gut bacteria in the genus Bacteroides include numerous operons for biosynthesis of diverse capsular polysaccharides (CPSs). The first two genes of each CPS operon encode a locus-specific paralog of transcription elongation factor NusG (called UpxY), which enhances transcript elongation, and a UpxZ protein that inhibits noncognate UpxYs. This process, together with promoter inversions, ensures that a single CPS operon is transcribed in most cells.
View Article and Find Full Text PDFJ Infect Dis
December 2024
Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, a division of the National Health Laboratory Service, Johannesburg, South Africa.
Background: Group B Streptococcus (GBS) is a leading cause of neonatal meningitis and sepsis and an important cause of disease in adults. Capsular polysaccharide and protein-based GBS vaccines are currently under development.
Methods: Through national laboratory-based surveillance, invasive GBS isolates were collected from patients of all ages between 2019 and 2020.
Microb Pathog
December 2024
Department of Laboratory Medicine, Affiliated Hospital, Jiangsu University, Zhenjiang, Jiangsu 212001, China. Electronic address:
The autophagy pathway plays a crucial role in resistance to bacterial infection in the host. Salmonella enterica serovar Typhi (S. Typhi), a human restricted pathogen, causes a systemic infection known as typhoid fever.
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