The capsular polysaccharide (CPS) of Staphylococcus aureus strain Smith was labelled by growth of bacteria in the presence of radioactive N-acetylglucosamine and was separated from labelled cell wall components by affinity chromatography on wheat germ agglutinin following dissolution of the cells by lysostaphin. The products were partially characterised chemically and immunochemically. Similar labelled components were found in the culture fluid during growth. In a pulse-chase experiment, cell-bound CPS was released continuously into the culture fluid at the same rate as cell wall turnover and there was no evidence of direct excretion of CPS.
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http://dx.doi.org/10.1016/0378-1097(91)90008-x | DOI Listing |
Clin Microbiol Rev
January 2025
Department of Medicine, Division of Pulmonary/Allergy/Critical Care, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
SUMMARY (the "pneumococcus") is a significant human pathogen. The key determinant of pneumococcal fitness and virulence is its ability to produce a protective polysaccharide (PS) capsule, and anti-capsule antibodies mediate serotype-specific opsonophagocytic killing of bacteria. Notably, immunization with pneumococcal conjugate vaccines (PCVs) has effectively reduced the burden of disease caused by serotypes included in vaccines but has also spurred a relative upsurge in the prevalence of non-vaccine serotypes.
View Article and Find Full Text PDFbioRxiv
January 2025
Institute for Systems Biology, Seattle, WA, USA.
Success of phage therapies is limited by bacterial defenses against phages. While a large variety of anti-phage defense mechanisms has been characterized, how expression of these systems is distributed across individual cells and how their combined activities translate into protection from phages has not been studied. Using bacterial single-cell RNA sequencing, we profiled the transcriptomes of ~50,000 cells from cultures of a human pathobiont, , infected with a lytic bacteriophage.
View Article and Find Full Text PDFMicroorganisms
January 2025
Emergency, Anesthesiological and Reanimation Sciences Department, Fondazione Policlinico Universitario A. Gemelli-IRCCS of Rome, 00168 Rome, Italy.
() is a Gram-negative, halophilic bacillus known for causing severe infections such as gastroenteritis, necrotizing fasciitis, and septic shock, with mortality rates exceeding 50% in high-risk individuals. Transmission occurs primarily through the consumption of contaminated seafood, exposure of open wounds to infected water, or, in rare cases, insect bites. The bacterium thrives in warm, brackish waters with high salinity levels, and its prevalence is rising due to the effects of climate change, including warming ocean temperatures and expanding coastal habitats.
View Article and Find Full Text PDFAntibiotics (Basel)
January 2025
State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Russia.
The emergence of multidrug-resistant hypervirulent (hvKp) has made it difficult to treat and control infections caused by this bacterium. Previously, the therapeutic effectiveness of phage-encoded depolymerase Dep_kpv74 in a mouse model of -induced thigh soft tissue infection was reported. In this study, the effect of Dep_kpv74 on blood parameters in mice, the proliferation and subpopulation composition of spleen lymphocytes, and the activity and stability of the enzyme at different pH and temperatures were further explored.
View Article and Find Full Text PDFBiochemistry
January 2025
Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States.
The exterior surface of the human pathogen is coated with a capsular polysaccharide (CPS) that consists of a repeating sequence of 2-5 different sugars that can be modified with various molecular decorations. In the HS:2 serotype from strain NCTC 11168, the repeating unit within the CPS is composed of d-ribose, -acetyl-d-galactosamine, and a d-glucuronic acid that is further amidated with either serinol or ethanolamine. The d-glucuronic acid moiety is also decorated with d-glycero-l-gluco-heptose.
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