There are also the so-called catabolic, plasmids carrying genes coding for the enzymes required in the breakdown of substances like naphthalene, salycylate and toluene. Some of these plasmids have a wide host range including most Gram-negative species. Genetic exchange between the chromosome and plasmids may occur. Flagellar antigens are difficult to prepare and therefore not generally used for serogrouping. The toxin attacks one of the elongation factors in translation during protein synthesis which is thus inhibited.
Strains produce a haemolysin, causing beta-haemolysis.
The production of large amounts of extracellular polysaccharides is associated with strains isolated from cases of cystic fibrosis. Endotoxin and exotoxin S are other virulence factors as are proteases and elastase. It can be founds in many parts of the human body as well as animals. It can be found in soil and on plants. It is found in faeces, sewage, water, soil and air.