Page:Bergey's manual of determinative bacteriology.djvu/966

 eruptive, Mediterranean or Marseilles fever and probably Indian tick typhus, Kenya typhus and South African tick-bite fever, though the identity of the latter with bou- tonneuse fever has been questioned). 6. Rickettsia australis Philip, 1950. (Agent of North Queensland tick typhus, Andrew, Bonnin and Williams, Med. Jour. Australia, 1946 (Aug. 24), 253; Rickettsia (Dermacentroxenus) australis Philip*, in Pullen, Communicable Diseases, Lea & Febiger Co., 1950, 786; Ixodoxenus australis Zhdanov, Opredelitel Virusov Celovska i Zivotmych, Izd. Akad. Med. Nauk, U.S. S.R., Moskau, 1953, 52 and 159.) aus.tra'lis. L. adj. australis southern. Minute, ellipsoidal or coccoidal forms re- sembling Rickettsia prowazekii morphologi- cally and in staining properties. Non-motile. Gram-negative. Cultivation: In yolk sacs of developing chicken eggs, at 32° to 35° C, poor to mod- erate growth reveals cocco-bacillary, short bacillary and diplo-bacillary forms. As in other members of the subgenus Derma- centroxenus, richer growth is reported on Zinsser agar tissue culture, in which both intracytoplasmic and intranuclear parasit- ism is readily demonstrated. Immunology: Duration of immunity is unknown in man in this recently discovered malady. Recovered guinea pigs remain solidly immune for at least 8 months and may show partial to complete immunity within 50 days to heterologous challenge with strains of Rickettsia conorii and R. typhi but no immunity toR. conorii 8 months or longer after recovery. No cross immunity was found with R. isutsugnmushi in white mice. Serology: Convalescent sera of patients contained agglutinins for Proteus OXig or 0X2 but none for OXK. The sera failed to fi.x complement in the presence of rickettsial antigens of epidemic or murine typhus. boutonneuse fever and American spotted fever, though homologous fixation was re- ported. Sera of recovered rabbits or guinea pigs have shown this agent to be a distinct member of the spotted-fever group in com- plement-fi.xation tests and to have a higher homologous than heterologous reaction in certain of these tests. Pathogenic for man; infected guinea pigs develop fever and scrotal reactions. White mice do not usually show signs of infection. In contrast to R. typhi, R. australis does not persist in the brains of white rats, though male rats may develop scrotal reactions when injected with cultures. Lethal effect: Intravenous injection of laboratory mice with cultures has not demonstrated the presence of a to.xin, in this respect resembling Rickettsia akari. Source: Observed by Andrew et al. (op. cit., 1946, 253) in smears of peritoneal exu- date of white mice injected with blood of two patients in North Queensland, Aus- tralia. Habitat: Tick transmission has not been demonstrated but has been presumed by the finding of either larval or adult Ixodes holocijclus on a few patients. The occurrence of primary eschars on patients implicates a probable acarine vector, but Dermacentor andersoni, a natural vector of Rickettsia rickettsii, does not experimentally transmit R. australis. Complement-fixing antibodies have been found in four kinds of native Queensland marsupials and in one species of rat. 7. Rickettsia akari Huebner et al., 1946. (Huebner, Jellison and Pomerantz, U. S. Public Health Rep., 61, 1946, IQ82; Rickettsia (Dermacentroxenus) akari Philip and Hughes, Amer. Jour. Trop. Med., ^8, 1948, 705; Acaroxenus varioleidis (sic) Zhdanov and Korenblit, Jour. Microbiol., Epidemiol, and Immunobiol. (Russian), No. 9, 1950, ■i2; Gamasoxenus muris Zhdanov, Opredelitel was published by Zhdanov and Korenblit the same year (Jour. Microbiol., Epidemiol, and Immunobiol. (Russian), No. 9, 1950 (reprint states September), 42). This name had also been used by these authors in a report to a scientific conference (Ukranian Int. imeni Mechnikov, Khar'kov, October 11, 1949), although, according to Rule 11, it was not eff"ec- tively published at that time so far as known.
 * Publishing date, June 16, 1950. By coincidence this name, including the same subgenus,