ACTINOBACILLUS PLEUROPNEUMONIAE DOES NOT REQUIRE UREASE ACTIVITY TO PRODUCE ACUTE SWINE PLEUROPNEUMONIA

摘要

The role in virulence of Actinobacillus pleuropneumoniae urease activity was investigated. A urease-negative mutant was isolated following transposon mutagenesis with a mini-Tn10 derivative. Both the parent strain and the urease-negative mutant exhibited identical LD(50) values in a murine infection model. Pig challenge confirmed that the urease-negative mutant was fully virulent, since experimental inoculation with 5x10(7) colony forming units resulted in an acute disease indistinguishable from that produced by the wild-type strain at the same dose. Our results demonstrate that urease activity is not required for the development of acute pleuropneumonia. [References: 24]