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Shimpachi Osumi

Bio: Shimpachi Osumi is an academic researcher. The author has contributed to research in topics: Rat-bite fever & Giemsa stain. The author has an hindex of 2, co-authored 2 publications receiving 72 citations.

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TL;DR: The skin tissue and also blood drawn from the patient were inoculated into monkeys, guinea pigs, and white rats, and it was possible to infect all the animals inoculated in this manner, and to transmit the disease from them to other animals.
Abstract: PLATE 33. Four cases of rat-bite fever have recently come under our observation , and we have been able to make a systematic study of two of them. The symptoms of the disease, which usually begin after an incubation period of from 10 to 27 days, consist of chills, fever, headache, and malaise. Inflammation is soon observed at the site of the apparently healed bites, with pains in the limbs on the affected side of the body, dark red skin eruptions, and swelling of the lymph glands. The attack with its local manifestations and high fever continues for from 3 to 7 days, the duration varying in individual cases. It alternates with an afebrile interval of 2 or 3 days. All the cases that came under our observation showed this picture, which may be considered typical of rat-bite fever. Our investigations were conducted in the following manner. On August 9, 1915, when one of the patients was showing active symptoms , a sterile excision was made of a small piece of skin from the arm. This piece of skin showed the typical exanthem described above. The excised tissue was placed under dark-field illumination and examined microscopically, and in it were observed numerous actively moving spirochmtm. The skin tissue and also blood drawn from the patient were inoculated into monkeys, guinea pigs, and white rats. It was possible to infect all the animals inoculated in this manner, and to transmit the disease from them to other animals. The study with the second patient was even more detailed. During the second attack a swollen lymph gland was punctured, and an India ink preparation made of the exudate, according to the 249

44 citations

Journal ArticleDOI
TL;DR: The organism is named Spirochaeta morsus muris and regard it as belonging to the Spironemacea (Gross) of the nature of treponema, and the movements of the spirochetes are very rapid, resembling those of a vibrio, and distinguish them from all other kinds of spiroChetes.
Abstract: 1. Since our first report on the discovery of the cause of rat-bite fever, we have been able to prove the existence of the same spirochete in five out of six more cases which have come under our observation. 2. The clinical symptoms of rat-bite fever are inflammation of the bitten parts, paroxysms of fever of the relapsing type, swelling of the lymph glands, and eruption of the skin, all occurring after an incubation period usually of from 10 to 22 days, or longer. 3. Our spirochete is present in the swollen local lesion of the skin and the enlarged lymph glands. But as the spirochetes are so few in number it is exceedingly difficult to discover them directly in material taken from patients. It is therefore better to inoculate the material into a mouse. In some cases the organism is found in the blood of the inoculated animal after a lapse of 5 to 14 days, or at the latest 4 weeks. 4. Generally speaking, the spirochetes present thick and short forms of about 2 to 5 µ and have flagella at both ends. Including the flagella, they measure 6 to 10 µ in length. Some forms in the cultures reach 12 to 19 µ excluding the flagella. The curves are regular, and the majority have one curve in 1 µ. Smaller ones are found in the blood and larger ones in the tissues. 5. The spirochetes stain easily. With Giemsa's stain they take a deep violet-red; they also stain with ordinary aniline dyes. The flagella, too, take Giemsa's stain. 6. The movements of our spirochetes are very rapid, resembling those of a vibrio, and distinguish them from all other kinds of spirochetes. When, however, the movements become a little sluggish, they begin to present movements characteristic of ordinary spirochetes. 7. For experimental purposes, mice, house rats, white rats, and monkeys are the most suitable animals. Monkeys have intermittent fever after infection, and spirochetes can be found in their blood, but they are not so numerous as in the blood of mice. Mice are the most suitable animals for these experiments, and they appear, as a rule, to escape fatal consequences. 8. The spirochete is markedly affected by salvarsan. 9. The organism is not present in the blood of all rats, and there is no relation between the species of the rat and the ratio of infection. We have never found the spirochete in healthy guinea pigs or mice. By permitting a rat infected with the spirochete to bite a guinea pig, the latter develops the disease. 10. We have succeeded in cultivating the spirochete in Shimamine's medium. 11. Among the spirochetes described in the literature or discovered in the blood of rats and mice, there may be some resembling our spirochete, but none of the descriptions agree with it fully. Hence we have named our organism Spirochaeta morsus muris and regard it as belonging to the Spironemacea (Gross) of the nature of treponema. 12. The spirochete can be detected in the bodies of patients. In seven cases out of eight, it disappears on recovery, only to reappear during the relapse. 13. The spirochete can be detected in about 3 per cent of house rats. These facts enable us to identify the cause of the disease. 14. There may be other causes than the spirochete for diseases following the bite of a rat. The cause, however, of rat-bite fever in the form most common in Japan is, we believe, the spirochete which we have described.

28 citations


Cited by
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Journal ArticleDOI
TL;DR: The infectious agents, their host species, pathogenicity (virulence factors and host susceptibility), diagnostic methods, therapy, epidemiology, transmission and prevention, and suggestions for future research are described.

159 citations

Journal ArticleDOI
TL;DR: A complete report of the findings in this epidemic of a disease similar to this of which the authors have found a record occurred in May and June 1925, at Chester, Pa.
Abstract: In January 1926 a small but explosive outbreak of illness occurred in a restricted area of Haverhill, Mass. Several physicians called by patients in this epidemic were struck by its unusual features, especially the abruptness of the onset, the peculiar eruption and the marked involvement of the joints. On January 22 we were called in consultation by the department of health. A preliminary report was made in February 1926.1A complete bacteriologic report was made by Parker and Hudson2in September 1926. The present paper is a complete report of the findings in this epidemic. The only previous epidemic of a disease similar to this of which we have found a record occurred in May and June 1925, at Chester, Pa. Studies of this outbreak were made by Dr. Charles Armstrong3and Dr. Harold B. Wood,4state epidemiologist. In that epidemic about 400 cases were discovered

74 citations

Journal ArticleDOI
TL;DR: A case of streptobacillary-ratbite fever successfully treated with penicillin is reported, and the therapeutic programs used have been compared with the results achieved in an attempt to determine optimal management with antimicrobials now available.
Abstract: RATBITE fever is an acute illness caused by Streptobacillus moniliformis or Spirillum minus , and characterized by chills, rash, and intermittent or relapsing fever. Arthritis or a local lesion at the bite-site, usually associated with regional lymphadenopathy, may also occur with the onset of other symptoms, depending upon the causative organism involved. Although penicillin is accepted as the treatment of choice for the disease, no agreement can be found in the literature concerning the most desirable dosage and duration of therapy. This paper reports a case of streptobacillary-ratbite fever successfully treated with penicillin. Previous American, Canadian, and British experience with cases in which the causative microorganisms were clearly demonstrated are reviewed, and the therapeutic programs used have been compared with the results achieved in an attempt to determine optimal management with antimicrobials now available. Report of a Case A 38-year-old white male radioisotope laboratory technician was admitted to the medical service

70 citations