Studies on Haemobartonella infection in the rat.

An organism which answers the published descriptions of Haemobartonella muris was isolated from Sprague-Dawley rats. The rats had either been splenectomized or were under other forms of stress. The organism was grown in a serum–tryptone medium which had been used successfully in the cultivation of Bartonella bacilliformis. The cultivated organism was infective for non-carrier Sprague-Dawley rats under different forms of stress; Wistar rats were not carriers and infections could not be induced.The effects of protein intake and tumors on the development of infection are also discussed. Rats fed a diet of 12% casein while carrying Flexner-Jobling tumors were more susceptible to infection than were those on diets of 0, 6, or 18% casein. Neither diets alone nor tumors alone placed sufficient stress on the animals for the development of symptoms.