Studies of Pplo Infection I . the Production of Cerebral Polyarteritis by Mycoplasma Oalli- Septicum in Turkeys; the Neurotoxic Property of the Mycoplasma* by Lewis

Jungherr (1), in 1949, noted the occurrence of encephalitis during several outbreaks of the chronic respiratory disease (CRD) of turkeys, then considered to be a virus disease, and demonstrated necrotizing and inflammatory lesions of the cerebral arteries in affected birds. Adler et al. (2), in 1954, cultivated a mycoplasma, now designated Mycoplasma gallisepticum, from the tissues of turkeys with CRD, and established the capacity of this organism to reproduce the sinusitis and aerocystitis characteristic of the natural disease. A neurotropic strain of M. gallisepticura was recovered by Zander in 1954 from the brain of a turkey with torticollis. This strain was shown by Cordy and Adler (3) to produce a fatal encephalopathy in young turkey poults, with the predominant lesions confined to the arteries of the central nervous system. This paper is concerned with studies of the pathology of cerebral polyarteritis at various stages of its development, with certain factors involved in the pathogenicity of M. gallisepticum, and with a neurotoxic property associated with concentrated suspensions of this organism. The therapeutic efficacy of gold salts, and tetracycline, previously established in other types of mycoplasma infection, will be demonstrated. Evidence will be presented indicating that the polyarteritis in this experimental model does not depend upon an immunologic mechanism, and more probably arises as the result of direct, toxic injury to the walls of cerebral arteries by the mycoplasma.