title: Infections caused by Rhodochrous.
abstract: Organisms conforming to "rhodochrous taxon" were isolated from three immunocompromised patients, suggesting a pathogenic role for the organisms. The organisms are partially acid-fast, gram-positive catalase positive rods which form orange or red colonies aerobically in three or four days on Sabouraud, Mueller-Hinton and Middlebrook 7H-10 agars. They are differenitated from Nocardia by morphology and ability to degrade ethylene glycol in 7H-10 media. Two of these clinical isolates and a reference strain were injected intraperitoneally into guinea pigs, half of which received methylprednisolone intramuscularly beginning three days prior to inoculation. Steroid-treated animals exhibited clinical illness, diffuse peritonitis and recovery of inoculated organisms whereas one of three nonsteroid-treated animals exhibited a localized abscess without recovery of organisms. This study suggests that rhodochrous may be pathogenic under conditions of immune compromise.
mesh_terms: D000368:Aged; D000818:Animals; D001847:Bone Diseases / Q000209:etiology / Q000382:microbiology; D005260:Female; D006099:Granuloma / Q000209:etiology / Q000382:microbiology; D006168:Guinea Pigs; D006689:Hodgkin Disease / Q000276:immunology; D006801:Humans; D007945:Leukemia, Lymphoid / Q000276:immunology; D008173:Lung Diseases, Obstructive / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000150:complications; D009615:Nocardia / Q000302:isolation & purification / Q000472:pathogenicity; D009617:Nocardia Infections; D011014:Pneumonia / Q000209:etiology / Q000382:microbiology; D014774:Virulence