results in splenectomized, haemobartonella- rods and coccus-like forms, often occurring free guinea pigs, rats, rabbits and monkeys in chains which also contain larger elements (Cercopithecus sabaeus). No infection or which have a deeply stained, bead-like anemia in unoperated mice, white rats, granule. In the early stages of infection, the young rabbits, young dogs or 3'oung guinea microorganisms may occur as thick bands pigs. By serial passage, the splenectomized or filaments stretching over the red blood cat has been found to carry the infection. cells, usually with a bead or granule. The Arsenical therapy : Complete sterilization bands take a bluish tint with Giemsa's stain, obtained with neoarsphenamine. while the more delicate forms stain a slate- Source: Found in the blood of infected violet. The bead is distinctly reddish. In splenectomized dog.s. the fully developed infection, rods and fila- Habitat: Found in dog fleas (Cteuocepha- ments predominate over rounded forms. The lides sp.) and in the erythrocytes of in- organisms may be scattered on the surfaces fected animals. Wide-spread distribution, of the red blood cells or may form a dense the infection occurring spontaneously in cap which is intensely stained. Threads may Europe, India, North and South Africa and be found radiating from a central portion, in North and South America. and reddish-stained material with ill-de- 9. Haemobartonella blarinae Tyzzer, ^^^^^ contours may occur at the ends of the 1942. (Proc. Amer. Philosoph. Soc, 85, 1942, branches of the threads. 332.) Pathogenic for the short-tailed shrew but bla.ri'nae. M.L. fem.n. Blarina a genus no* for deer mice or white mice. Causes of shrews; M.L. gen.noun blarinae of anemia in the shrew. Blarina. Habitat: Found in the blood of the short- Extremeh^ polymorphic with delicate iaWedshve-^^ {Blarina brevicauda). Genus IV. Eperythrozoon Schilling, 1928.* (Schilling, Klin. Wochnschr., 7^, 1928, 1854; Gyromorpha Dinger, Nederl. tijdschr. geneesk., 72, 1928, 5903.) Ep.e.ryth.ro.zo'on. Gr. prefix epi- on; Gr. adj. erythrus red; Gr. noun zoum or zoon living thing, animal; M.L. neut.n. Eperythrozoon (presumably intended to mean) animals on red (blood cells). Microorganisms found in blood plasma and on erythrocytes. Stain well with Romanow- sky-type dyes, then appearing as rings, coccoids or short rods, 1 to 2 microns in greatest dimension, and staining bluish or pinkish violet; show no differentiation of nucleus and cytoplasm with this technique. Not acid-alcohol-fast. Gram-negative. Not cultivated in cell-free media. Splenectomy activates latent infection. Arthropod transmission has been established for one species (Weinman, Trans. Amer. Philosoph. Soc, 33 (N.S.), 1944, 321). The organisms in this genus have been considered as belonging to the Protozoa by Neitz, Alexander and du Toit (Onderstepoort Jour. Vet. Sci., 3, 1934, 268) and to the bacteria b}' Mesnil (Bull. Soc. path, exot., 22, 1929, 531) and by Tyzzer (in Weinman, op. cit., 1944, 244). The evidence at hand favors the inclusion of this group among those organisms which are not clearly protozoan in nature but which appear to be closely related to the bacteria. The tj'pe species is Eperythrozoon coccoides Schilling. Key to the species of genus Eperythrozoon. f I. Found in rodents. A. Found in the albino mouse. 1. Eperythrozoon coccoides.
- Revised by Dr. David Weinman, Department of Microbiology, Yale University, New
Haven, Connecticut, September, 1955. t For convenience this key has been arranged on the basis of host relationships; it is not intended to signify that this is the onh^, or the most important, or even a valid criterion for the determination of species. The full descriptions of the species should be consulted.
