Bacterial pathogens use a variety of methods to avoid the host immune system and perpetuate disease. Streptococcus pneumoniae, for example, uses capsular polysaccharides as a major virulence factor to avoid phagocytosis by host immune cells. These pneumococcal polysaccharides coat the outside of the bacterium and are made up of simple carbohydrates that provide cellular structure, cellular communication, and energy storage. Currently, over 90 different capsular serotypes are known, each exhibiting enormous structural diversity that contributes to differences in immunogenicity and antigenicity. These differences can be associated to distinct epidemiological properties, enabling the identification of different serotypes.

In contrast, enteric pathogens like Clostridium perfringens cause disease through the release of harmful toxins that contribute to gas gangrene and intestinal infection. This bacterial species is known to produce up to 17 toxins, with individual strains producing a subset of these. The toxins produced by C. perfringens provides the basis of a toxinotyping classification scheme that organizes strains into five types (A-E).

The inherent differences in pneumococcal polysaccharides and clostridial toxins has not only provided researchers with a way to characterize the pathogenicity of different strains, but a means to track them during outbreaks as well. Further, because these antigens are extracellular in nature, they provide ideal targets for vaccines and therapeutics.

To support the continuing research on bacterial pathogens, ATCC provides purified polysaccharide and toxin preparations. Our growing collection encompasses 31 types of pneumococcal polysaccharides, including those represented in current vaccines, and three types of clostridial toxins, including perfringolysin O, beta toxin, and enterotoxin. Explore our portfolio today!