The vapA co-expressed virulence plasmid gene vcgB (orf10) of the intracellular actinomycete Rhodococcus equi.

The virulence plasmid of the pathogenic actinomycete Rhodococcus equi is essential for proliferation of this pathogen in macrophages and the development of disease. The pathogenicity island of this plasmid encodes a family of virulence-associated proteins (Vap), one of which (VapA) is a virulence factor. This paper describes the vcgAB operon (vapA co-expressed gene), located upstream of the vapA operon.

Differential mRNA stability of the vapAICD operon of the facultative intracellular pathogen Rhodococcus equi.

The gene encoding virulence associated protein A (VapA) is clustered with three vapA homologues (vapICD) within the pathogenicity island of the virulence plasmid of Rhodococcus equi. Northern blot analysis showed a vapA transcript of c. 700 nucleotides (nt) suggesting that vapA is a monocistronic transcript.

The LysR-type transcriptional regulator VirR is required for expression of the virulence gene vapA of Rhodococcus equi ATCC 33701.

The virulence of the intracellular pathogen Rhodococcus equi in foals is dependent on the presence of an 81-kb virulence plasmid encoding the virulence protein VapA. Expression of this protein is induced by exposure to oxidative stress, high temperatures, and low pHs, which reflect the conditions encountered by R. equi when it enters the host environment.

Isocitrate lyase of the facultative intracellular pathogen Rhodococcus equi.

Isocitrate lyase is the first enzyme of the glyoxylate shunt which is required for the assimilation of fatty acids and acetate. The intracellular pathogen Rhodococcus equi contains high activities of this enzyme following growth on acetate and lactate, indicating that it plays an important role in the metabolism of these substrates. The gene encoding isocitrate lyase (aceA) was cloned and sequenced.