FAMILY I. RICKETTSIACEAE 



943 



to the genera Amblyomma, Dermacentor, 

 Rhipicephalus, Ornithodoros and Haema- 

 phjsnlis have been experimentally infected. 

 The agent is transmissible through tick ova. 

 The etiological agent of Rocky Mountain 

 spotted fever, Sao Paulo exanthematic 

 t5'phus of Brazil, Tobia fever of Colombia 

 and spotted fevers of Minas Gerais and 

 Mexico, which are all transmitted to man by 

 the bite of infected ticks. Gould and Miesse 

 (Proc. Soc. Exp. Biol, and Med., 85, 1954, 

 558) reported the first isolation in the 

 U. S. A. of identified infection in a Microtus 

 field mouse. 



5. Rickettsia conorii Brumpt, 1932. 

 {Rickettsia conori (sic) Brumpt, Compt. 

 rend. Soc. Biol., Paris, 110, 1932, 1199; 

 Rickettsia megaioi var. pijperi Franco do 

 Amaral and Monteiro, Mem. Inst. Butan- 

 tan, 7, 1932, 361; Rickettsia bland Cami- 

 nopetros, l""' Cong. Internat. Hyg. Med- 

 iterr., Rapports et Compt. rend., 2, 1932, 

 202; Dermacentroxenus rickettsi var. pijperi 

 Mason and Alexander, Onderst. Jour. Vet. 

 Sci. and Anim. Ind., 13, 1939, 74; Derma- 

 centroxenus rickettsi var. conori Mason and 

 Alexander, loc. cit.; Rickettsia {Dermacen- 

 troxenus) conori Philip, Amer. Jour. Hyg., 

 37, 1943, 307; Dermacentroxenvs conori 

 Steinhaus, Insect Microbiology, 1946, 339; 

 Dermacentroxemis pijperi Macchiavello, 

 Prim. Reunion Interamer. del Tifo, Mexico, 

 1947, 414; Ixodoxenus conori Zhdanov, 

 Opredelitel Virusov Celovska i Zivotmych, 

 Izd. Akad. Med. Nauk, U.S.S.R., Moskau, 

 1953, 52 and 157.) 



co.no'ri.i. M.L. gen.noun conorii of 

 Conor; named for A. Conor, the first to 

 describe adequately boutonneuse fever. 



Resembles Rickettsia rickettsii. In the tick, 

 diplococcoid and diplobacillary forms pre- 

 dominate, though they are smaller and more 

 coccoid when they occur in compact masses. 

 In tissue cultures the organisms are lanceo- 

 late, diplococcoid and diplobacillary, oc- 

 curring in the nuclei as well as in the cyto- 

 plasm of the cells. 0.3 to 0.4 by 1.0 to 1.75 

 microns. Non-motile. Stain purplish with 

 Giemsa's stain, blue with Castaneda's 

 stain and bright red with a blue background 

 with Macchiavello's stain. Gram-negative. 



Cultivation: May be cultivated in plasma 



tissue culture of mammalian cells, in modi- 

 fied Maitland media and in the yolk sacs of 

 chick embryos. Weyer (Acta Tropica, 11, 

 1954, 194) found differences in growth of 

 Kenya and South African strains compared 

 to a classic strain from the Mediterranean 

 area. 



Immunology: The disease is related im- 

 munologically to Rocky Mountain spotted 

 fever with which it cross immunizes, but 

 spotted-fever vaccine does not protect 

 against the Mediterranean, Asiatic and 

 South African strains of boutonneuse fever. 

 Attempts to produce potent vaccines either 

 from tick or culture sources have so far been 

 ineffective. 



Serology: Cross fixation occurs with R. 

 rickettsii by complement-fixation test. 

 Possesses a common antigenic factor with 

 Proteus 0Xi9 and OX2 but not with OXK. 



Pathogenic for man and guinea pigs. Also 

 pathogenic in var3qng degrees for dogs, 

 horses, spermophiles, monkeys, rabbits, 

 gerbilles and white mice. Boutonneuse 

 fever is a much less virulent infection for 

 the guinea pig than is Rocky Mountain 

 spotted fever. A temperature reaction, ac- 

 companied by scrotal swelling, occurs but 

 there is no sloughing. There is practically 

 no mortality. Passsage in guinea pigs is ac- 

 complished most effectively by transfer of 

 testicular washings. In man there occur 

 localized primary sores (taches noires) at 

 the site of the tick bite and inflammatory 

 reactions in the regional lymph nodes. A 

 febrile reaction with exanthema occurs, and 

 mortality is low. 



Source: Observed by Caminopetros 

 (Compt. rend. Soc. Biol., Paris, 110, 1932, 

 344) in smears from the tunica vaginalis of 

 guinea pigs inoculated with infected dog 

 ticks (Rhipicephalus sanguineus). 



Habitat: Found in the brown-dog tick 

 (Rhipicephalus sanguineus) and also in the 

 ticks Amblyomma hebraeiim, Haemaphysalis 

 leachii, Rhipicephalus appendiculatus , R. 

 evertsi and Boophilus decoloratus. Trans- 

 missible through the ova of ticks to follow- 

 ing generations. The probable animal reser- 

 voir is the dog in the Mediterranean area 

 and, in addition, perhaps veld rodents in 

 South Africa. The etiological agent of 

 boutonneuse fever in man (also known as 



