1098 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



rocha-liinae. It causes a febrile illness 

 in man in which relapses occurred 3 to 

 5 times as in trench fever. Rickettsia 

 weigli was agglutinated by convalescent 

 sera but not by sera from typhus pa- 

 tients. Convalescent sera gave no posi- 

 tive Weil-Felix reaction. 



Wolbachia pipientis Hertig. (Rickett- 

 sia of Culex pipiens, Hertig and Wolbach, 

 Jour. Med. Res., U, 1924, 329; Hertig, 

 Parasitology, 28, 1936, 453.) This is the 

 type species of the genus Wolbachia 

 Hertig {loc. cit ). Found in the ovaries 

 or testes of the mosciuito, and present in 

 all stages of the mosquito's development. 

 The outstanding morphological charac- 

 teristic of the organism is great pleomor- 

 phism. Minute coccoids and short rods 

 may be considered typical, but the usual 

 microscopic field consists of various 

 shapes and sizes. Som.e forms show 

 bipolar staining with the Giemsa stain. 

 The organism is a harmless parasite of 

 the mosquito. Laboratory animals are 

 apparently not susceptible. 



The following unnamed rickettsiae 

 isolated from animals or seen in anihials 

 are included in Steinhaus' list of rickett- 

 siae (Insect Microbiology. Ithaca, 1946, 

 344): 



A rickettsia was isolated by Parker, 

 Kohls, Cox and Davis (Pub. Health 

 Rept., 5Jf, 1939, 1482) from a tick {Avi- 

 hlyomma maculatiun) . It is pathogenic 

 for guinea pigs and the disease is 

 referred to as the maculatum- disease. 

 There is complete cross immunity in 

 guinea pigs between this infection and 

 Rocky Mountain spotted fever and 

 boutonneuse fever, but it differs from 

 these diseases in some particulars. 



A rickettsia-like organism was isolated 

 from the reduviid bug {Triatoma ruhro- 

 fasciata) by Webb (Parasitology, 32, 

 1940, 355). It was pathogenic for some 

 laboratory animals and was maintained 

 in guinea pigs for 5 passages. The 

 rickettsiae were transmissible to the 



next generation through the egg of the 

 reduviid bug. 



A spotted fever type of rickettsia was 

 isolated by Anigstein and Bader (Texas 

 Repts. Biol. Med., 1, 1943, 105) from the 

 dog tick {Rhipicephalus sanguineus) 

 taken from normal dogs. It was patho- 

 genic for rabbits and guinea pigs. 



A rickettsia was isolated by Anigstein 

 and Bader (Texas Repts. Biol. Med., 1, 



1943, 298, 389) from ticks {Amhlyomma 

 americanum) collected in Texas. They 

 believed it to be the cause of bullis fever. 



Rickettsiae were observed by Enigh 

 (Berl. u. Mlinch. Tierarztl. Wchnschr., 

 1942, 25) in the leucocytes of a bison 

 calf. No arthropod was associated with 

 this rickettsia. 



A rickettsia-like agent pathogenic for 

 guinea pigs was reported by Tatlock 

 (Proc. Soc. Exp. Biol, and Med., 57, 



1944, 95). The animals had been in- 

 jected with blood from a patient with 

 "pre tibial" fever. No arthropod vector 

 was indicated. 



Three species of rickettsia-like or- 

 ganisms isolated from the wood-tick 

 (Dermacentor andersoni) are described 

 by Noguchi (Jour. Exper. Med., 43, 

 1926, 518-521). These were named Ba- 

 cillus rickettsiformis, Bacillus pseudo- 

 xerosis and Bacillus equidistans. All 

 could be cultivated on cell-free media 

 and none was pathogenic for laboratory 

 animals. 



Appendix III: Unnamed rickettsia- 

 like organisms seen in the tissues of 

 insects. 



Hertig and Wolbach (Jour. Med. Res., 

 44, 1924, 329) list sixteen species of 

 arachnids and twenty-three species of 

 insects which are hosts to rickettsiae or 

 rickettsia-like organisms. 



Wolbach (Jour. Amer. Med. Assoc, 84, 

 1925, 723) reports hosts of non-patho- 

 genic rickettsiae which include fourteen 

 species of arachnids (ticks, mites and 

 spiders) and twenty-two species of in- 

 sects distributed in nine orders, including 



