The Rat-Bite Fever Spirochete, with Comparative Study of Human, Wild Rat and Field Vole Strains

Abstract

In 1915 Futaki, Takaki, Taniguchi and Osumi! discovered in a swollen lymph gland of a rat-bite fever patient a spirochete which they regarded as the cause of this disease. A month later, Ishiwara, Ohtawara and Tamura" succeeded in finding the same spirochete in a guinea-pig experimentally infected with rat-bite fever, transmitted by the bite of a wild rat. Subsequently Kitagawa, Kato, Abe and Mukoyama," Futaki and his associates/ Kaneko and Okuda," and ROW,6 in India, each group working separately, again demonstrated the existence of this spirochete, making use of specimens obtained from human beings j and Ido, Ito, Wani and Okuda" showed that there is a specific relation between Futaki's spirochete and antibody in the blood of patients. Spirochaeta morsus-muris, as it was designated by Futaki and his associates," has since been proved beyond doubt to be the causative agent of the rat-bite disease occurring in Japan. In addition to the investigations just noted, there have been published in Japan several papers on the rat-bite fever spirochete. A number of contradictory statements in these publications have led us to repeat certain experiments; moreover our interest in the morphologic similarity between this spirochete and that found in the blood of the field vole by Miyajima has made a comparative study of these strains advisable .. For this experiment we selected four strains of the spirochete, the human~and 2,* the wild rat and the field vole strains.

Rat-Bite Fever

“…The clinical picture was essentially the same as that described by other authors. 5. The Spirochaeta morsus-muris was recovered from serum taken from the bite wound, by examination under dark-field illumination.…”

Characteristics of a Hepatozoonosis in Lungs of Japanese Black Bears(Ursus thibetanus japonicus).

“…Infections by the parasite have been found in many families of carnivores [3,6,8,18], but the extent of host specificity for the cystic stage in the intermediate hosts is not known. In Japan, few reports about Hepatozoon species have been published, but such species have been found in wild rats [11], wild foxes [12], dogs [14], and wild martens [18]. No Hepatozoon species has been reported as being found in Japanese black bears.…”