FAMILY II. CHLAMYDIACEAE 957 



Genus VIII. Rickettsiella Philip, 1956. 



{Coxiella Dutky and Gooden, Jour. Bact., 63, 1952, 749; not Coiiella Philip, Amer. Jour. 

 Hyg., 37, 1943, 306; Philip, Canad. Jour. Microbiol., 2, 1956, 267.) 



Ri.ckett.si.el'la. M.L. dim. ending -ella; M.L. fem.n. Rickettsiella named for H. T. Rick- 

 etts, one of the discoverers of the organisms bearing his name, who eventually lost his life 

 while studying typhus infection in Mexico. 



Minute, intracellular, rickettsia-like organisms which are pathogenic for certain insect 

 larvae but which are not known to be pathogenic for any vertebrates. Filterable. Associated 

 with microscopic, intracellular, crystalline inclusions and reported to infect cell nuclei 

 (though this needs to be confirmed). 



The type species is Rickettsiella popilliae (Dutky and Gooden) Philip. 



1. Rickettsiella popilliae (Dutky and death, the infection eventually spreads to 



Gooden, 1952) Philip, 1956. (Coxiella popil- discolor the entire larva. Nuclei of infected 



liae Dutky and Gooden, Jour. Bact., 63, cells are reported to be invaded, but no 



1952, 743; Rickettsia melolonthae Krieg, clear evidence of this has been illustrated or 



Ztschr. f. Naturforsch., 706, 1955, 35; Philip, described. The organisms are fairly uni- 



Canad. Jour. Microbiol., 2, 1956, 267.) form, small, kidney-shaped rods, 0.2 by 0.6 



po.pil'li.ae. M.L. fem.n. Popillia a genus micron under the electron microscope, with 



of beetles; M.L. gen. noun popilliae of Pop- denser areas at the poles or outlined by a 



illia. capsule-like structure. Pass 7-pound me- 



Occurs intracellularly in the Japanese dium and 13-pound fine porosity Mandler 



beetle (Popillia japonica), initially in the filters. Capable of infecting healthy larvae 



fat bodies of infected larvae, causing a blu- by subinjection of hemolymph. E.xperimen- 



ish discoloration. Other tissues become in- tal infection has also been produced by con- 



fected as ruptured cells release the organ- tamination of soil in which healthy larvae 



isms into the hemolymph, and, preceding were fed. 



FAMILY II. CHLAMYDIACEAE RAKE, Fam. Nov.* 



(Chlamydozoaceae Moshkovskiy, Uspekhi Souremennoi Biologii (Russian) (Advances in 

 Modern Biology), 19, 1945, 12.) 



Chla.my.di.a'ce.ae. M.L. neut.n. Chlamydia type genus of the family; -aceae ending to 

 denote a family; M.L. fem.pl.n. Chlamydiaceae the Chlamydia family. 



Small, coccoid microorganisms with a characteristic developmental cycle. Stain with 

 aniline dyes. Gram-negative. Have not been cultivated in cell-free media. Obligate, intra- 

 cytoplasmic parasites or saprophytes. Found in various warm-blooded animals, where they 

 are usually pathogenic. 



Key to the genera of family Chlamydiaceae. 



I. Non-cultivable in chicken embryonic tissues. 



A. Organisms coccoid; do not exhibit pleomorphism. 



Genus I. Chlamydia, p. 958. 



B. Organisms usually coccoid or ellipsoidal; exhibit marked pleomorphism. 

 1. Pleomorphic forms small (200 millimicrons to 2 microns). Pathogenic. 



a. Occur intracytoplasmically as prominent colonies. 



Genus II. Colesiota, p. 959. 



* Prepared by Prof. Geoffrey W. Rake, University of Pennsylvania, Philadelphia, Penn- 

 sylvania, December, 1955. 



