Rhodococcus equi is a facultative intracellular bacterium that can escape from bactericidal mechanisms associated with phagocytosis. Virulence-associated protein A (VapA), encoded on a virulence-associated plasmid, is essential for intracellular survival in macrophages, but its function is not known. Here, we show that the extracellular addition of recombinant glutathione S-transferase (GST)-Va...

Virulent Rhodococcus equi, which is a well-known cause of pyogranulomatous pneumonia in foals, possesses a large plasmid encoding virulence-associated 15- to 17-kDa antigens. Foal and soil isolates from five countries-Argentina, Australia, Canada, France, and Japan-were investigated for the presence of 15- to 17-kDa antigens by colony blotting, using the monoclonal antibody 10G5, and the gene c...

The in vitro activities of magainin II, nisin, and ranalexin alone and in combination with other antimicrobial agents against six clinical isolates of Rhodococcus equi were investigated by MIC and time-kill studies. All isolates were more susceptible to nisin. A positive interaction was observed when the peptides were combined with ampicillin, ceftriaxone, rifabutin, rifampin, azithromycin, cla...

The exosubstance of Rhodococcus equi in a prepurified form strongly enhanced the hemolytic effect of certain strains of Listeria monocytogenes. The strains which produced positive synergic hemolysis with this exosubstance were also pathogenic for guinea pigs and white mice. The other strains, which remained nonhemolytic in the presence of the R. equi. exosubstance, were apathogenic for those an...

Microbe-mediated soil uptake is the largest and most uncertain variable in the budget of atmospheric hydrogen (H2 ). The diversity and ecophysiological role of soil microorganisms that can consume low atmospheric abundances of H2 with high-affinity [NiFe]-hydrogenases is unknown. We expanded the library of atmospheric H2 -consuming strains to include four soil Harvard Forest Isolate (HFI) Strep...

Little is known about the iron acquisition systems of the soilborne facultative intracellular pathogen Rhodococcus equi. We previously reported that expression of iupABC, encoding a putative siderophore ABC transporter system, is iron regulated and required for growth at low iron concentrations. Here we show that disruption of iupA leads to the concomitant accumulation of catecholates and a chr...

The soil-dwelling, saprophytic actinomycete Rhodococcus equi is a multihost, facultative intracellular pathogen of macrophages. When inhaled by susceptible foals, it causes severe bronchopneumonia. It is also a pathogen of pigs, which may develop submaxillary lymphadenitis upon exposure. R. equi isolates obtained from foals and pigs possess conjugative plasmids housing a pathogenicity island (P...

BACKGROUND Rhodococcus equi is one of the most significant bacterial pathogens affecting foals up to 6 months of age worldwide. Rhodococcosis is present in Poland however information about molecular characterization of R. equi isolates is scarce. This study describes molecular characterization of Rhodococcus equi infection on 13 horse breeding farms in Poland between 2001 and 2012. Samples were...

Rhodococcus equi is a gram-positive intracellular pathogen that can cause severe bronchopneumonia in foals and AIDS patients. It has been reported that advanced infection of foals is characterized by tissue necrosis, coinciding with the presence of degenerate bacteria-laden macrophages. Here, we report that the possession of the VapA-expressing plasmid, which has been previously correlated with...

Rhodococcus equi can cause severe infections in people, particularly in immunocompromised individuals. The R. equi virulence plasmids (vap) encoding vapA and vapB are linked to development of infections in domestic animals. Recently, a novel virulence plasmid, vapN, was identified in isolates cultured from cattle, but its prevalence or significance in human R. equi infections has not been exten...