Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Production of Apx toxins by field strains of Actinobacillus pleuropneumoniae and Actinobacillus suis.

Abstract

114 A. pleuropneumoniae field strains originating from 10 countries, representing biotypes 1 and 2 and all serotypes, except serotype 4 of biotype 1, were examined. A. suis type strain NCTC 10840 and 4 Dutch A. suis field strains were also tested. Toxin-containing culture filtrates were obtained and tested for the presence of Apx toxins using 5 monoclonal antibodies in a dot blot assay. The molecular masses of the proteins that reacted with the monoclonal antibodies were determined by Western blot analysis. Culture filtrates of the reference strains of biotype 1, serotypes 8 and 11, were used as references. The field strains secreted either ApxI, ApxII, ApxI and ApxII, or ApxII and ApxIII and secreted no other cytolytic activities. Proteins similar to ApxI and ApxII were also produced by A. suis.