It has been asserted that humoral immunity is an important potentiating factor in pathogenesis of infective endocarditis, in that prior immunization to certain bacteria may predispose the host to endocarditis caused by those organisms. If so, possible future vaccination of humans with streptococcal antigens for the prevention of dental caries might increase the susceptibility of the population ...

Regulatory T cells (Tregs) participate in the control of the immune response. In the human system, an IL-10-secreting, T regulatory type 1 cell (Tr1)-like subset of Tregs can be induced by concurrent cross-linking of the TCR and CD46 on naive CD4(+) T cells. Because many viral and bacterial pathogens, including the major human pathogen Streptococcus pyogenes, bind to CD46, we asked whether this...

Phylogenetically conserved serine protease cascades play an important role in invertebrate and vertebrate immunity. The mammalian coagulation system can be traced back some 400 million years and shares homology with ancestral serine proteinase cascades that are involved in, for example, Toll receptor signaling in insects and release of antimicrobial peptides during hemolymph clotting. In the pr...

The in vitro activity of chephaloridine, cephalexin, cefatrizine (BL-S640), and cephapirin (BL-P-1322) was evaluated by the serial dilution method against pathogenic gram-positive and gram-negative bacteria isolated from bovine udders and neonatal calf diseases. Cephapirin showed the comparatively greatest activity against the most common streptococcal species associated with bovine mastitis, w...

The pharyngeal aspirates collected from 400 babies at the time of delivery were examined for the presence of bacteria, especially group B streptococci. Aspirates from 79 babies were found to contain viable bacteria, including 4 with group B streptococci; one of these 4 babies developed streptococcal meningitis within 24 hours. The group B streptococci were seen on a Gram-stained film of the asp...

Serum opacity factor (SOF) is a virulence determinant expressed by a variety of streptococcal and staphylococcal species including both human and animal pathogens. SOF derives its name from its ability to opacify serum where it targets and disrupts the structure of high-density lipoproteins resulting in formation of large lipid vesicles that cause the serum to become cloudy. SOF is a multifunct...

There are few reports in the literature (1--4) on the pyrogenicity of streptococci or streptococcal filtrates. The most recent detailed investigations on streptococcal pyrogenic activity were reported by Stetson (5) and Watson (6). Stetson reported on the endotoxic activity of Group A streptococci grown in vitro. On the basis of studies with lysates of streptococci disrupted in a Mickle disinte...

Sore throat is most commonly caused by viruses, but when caused by bacteria, the most important is group A streptococcus (GAS). The aim of these guidelines is to determine optimal treatment for streptococcal sore throat and reasonable indications for tonsillectomy, as well as recommend how to differentiate streptococcal infection for which antibiotics are justified, from numerous other sore thr...

The sequence of the fibronectin-binding domain of the fibronectin-binding protein of Streptococcus pyogenes (Sfb protein) was determined, and its role in streptococcal adherence was investigated by use of an Sfb fusion protein in adherence studies. A 1-kb DNA fragment coding for the binding domain of Sfb protein was cloned into the expression vector pEX31 to produce an Sfb fusion protein consis...

Immunity to common bacteria requires the generation of antibodies that promote opsonophagocytosis and neutralise toxins. Pooled human immunoglobulin is widely advocated as an adjunctive treatment for clinical Streptococcus pyogenes infection however, the protein targets of the reagent remain ill defined. Affinity purification of the anti-streptococcal antibodies present within pooled immunoglob...