BACKGROUND Porphyromonas gingivalis inhibits oral epithelial wound healing in vitro more strongly than other oral bacteria, but it is unknown why P. gingivalis is such a potent inhibitor of wound healing. OBJECTIVE Therefore, the aim of this study was to investigate the influence of major virulence factors of P. gingivalis on wound healing in an in vitro wound-healing model. The influence of ...

Streptococcus pneumoniae is a pathogen that causes serious invasive infections, such as septicemia, meningitis and pneumonia in addition to mild upper respiratory tract infections. Protection from pneumococcal diseases is thought to be mediated mainly by serotype-specific antibodies to capsular antigens. Pneumococcal conjugate vaccine consists of sugars (polysaccharides) from the capsule of the...

Bacterial capsular polysaccharides are virulence factors and are considered T cell-independent antigens. However, the capsular polysaccharide Sp1 from Streptococcus pneumoniae serotype 1 has been shown to activate CD4(+) T cells in a major histocompatibility complex (MHC) class II-dependent manner. The mechanism of carbohydrate presentation to CD4(+) T cells is unknown. We show in live murine d...

The rapid spread of antibiotic-resistance among pathogenic bacteria poses a serious risk for public health. The search for novel therapeutic strategies and antimicrobial compounds is needed to ameliorate this menace. The bifunctional metalloenzyme CapF is an antibacterial target produced by certain pathogenic bacteria essential in the biosynthetic route of capsular polysaccharide, a mucous laye...

The relationship between capsular polysaccharide types 5 and 8 and resistance of Staphylococcus aureus to oxacillin was studied with a collection of 406 clinical isolates from six French hospitals. Of 175 type 5 isolates, 84 (48%) were resistant to oxacillin. In contrast, only 8 of 160 type 8 isolates (5%) and 5 of 71 nontypeable isolates (7%) were resistant to oxacillin. Therefore, capsular ty...

The ability of the encapsulated species Bacteroides fragilis to adhere to rat peritoneal mesothelium was compared to the adherence of unecapsulated strains of Bacteroides (B. distasonis, B. vulgatus, B. thetaiotaomicron, B. ovatus, and B. "other"). Adherence was assayed by attaching plexiglas plates containing 8-mm holes to the peritoneal mesothelium of anesthetized rats. Cell suspension (0.25 ...

In the past decade, several outbreaks of cholera have been reported to be caused by Vibrio cholerae O139, a strain which differs from the more common O1 strain in that the former is encapsulated. The hexasaccharide repeating subunit has been isolated from the V. cholerae O139 capsular polysaccharide by digestion with a recently discovered polysaccharide lyase derived from a bacteriophage specif...

The capsular polysaccharide of Burkholderia pseudomallei is an essential virulence determinant that is required for protection from host serum cidal activity and opsonophagocytosis. In this study, the immune response directed against a B. pseudomallei capsule mutant (JW270) was investigated in an acute respiratory murine model. JW270 was significantly attenuated in this model ( approximately 2 ...

Cryptococcus neoformans is a facultative intracellular pathogen. The most distinctive feature of C. neoformans is a polysaccharide capsule that enlarges depending on environmental stimuli. The mechanism by which C. neoformans avoids killing during phagocytosis is unknown. We hypothesized that capsule growth conferred resistance to microbicidal molecules produced by the host during infection, pa...

lon mutants of Escherichia coli K-12 are defective in an ATP-dependent protease, are UV sensitive, and overproduce the capsular polysaccharide colanic acid. Six structural genes needed for capsular polysaccharide synthesis (cps) are transcriptionally regulated by lon as well as by three other regulatory genes, rcsA, -B, and -C (S. Gottesman, P. Trisler, and A. S. Torres-Cabassa, J. Bacteriol. 1...