Isolation of Bacillus licheniformis var. endoparasiticus from the blood of rheumatoid arthritis patients and normal subjects.

Sixty-five samples of blood from patients with rheumatoid arthritis and 94 from control subjects were examined by multiple culture and monthly subculture for periods of up to 33 months to detect the revision stages of Bacillus licheniformis var. endoparasiticus (BLE), which exists as L-forms in blood. Isolation of BLE were obtained more often from the blood of control subjects than from rheumatoid patients during the first 6 months of incubation, when there was clustering of positive cultures within samples. Thereafter, the isolation rate was similar for the two groups and positive cultures were distributed randomly between samples. Isolation of diphtheroid intermediate reversion stages (phase A and B) occurred mainly during the first year of incubation, but isolations of the fully reverted sporing bacillus (phase C) increased in frequency with incubation time, particularly from cultures with a high rate of desiccation during prolonged incubation. The proportion of different phases of BLE amongst the isolates and the distribution of the phases with incubation time were similar for the rheumatoid-arthritis patients and the normal subjects.