Use of DNA fingerprinting for accurate typing of Actinobacillus pleuropneumoniae.

DNA fingerprinting was tested as a method for detailed differentiation of 23 strains of the causal agent of porcine pleuropneumonia--Actinobacillus pleuropneumoniae. The set consisted of twelve reference strains, each representing one serotype, and eleven field strains belonging to serotype 9 which occurs most frequently in the Czech Republic. Nine of the reference strains could be differentiated from each other and from serotypes 1, 9 and 11, but a very close relatedness was demonstrated among the latter three by repeated examination. Four DNA types were identified among the twelve serotype 9 strains. The findings are discussed within the context of the production and efficiency of industrial and autogenous vaccines.