Isolation of Mycoplasma arthritidis from the joint fluid of boars

During an outbreak of a disease in a swine insemination centre in Bavaria, Fed. Rep. of Germany, characterized by conjunctivitis, severe polyarthritis and infertility mycoplasmas have been isolated from the joint fluids of the three boars investigated. Two of the isolate could be typed as Mycoplasma (M.) arthritidis which causes arthritis in rats, mice and rabbits, the third as M. collis, a probably apathogenic rodent mycoplasma species. One of the two isolated M. arthritidis strains (strain D 263) was injected intravenously in rats and mice, which developed mild to severe polyarthritis or even died, depending on the numbers of organisms inoculated. Since the bacteriological and virological investigations of the joints of boars did not yield a causative agent, it is to suppose that M. arthritidis played the substantial role in the production of the disease of the boars. It is very likely that the boars caught the mycoplasmas from rodents infected with the isolated species.