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MANUAL OF DETERMINATIVE BACTERIOLOGY 



1. Eperythrozoon coccoides Schilling. 

 (Schilling, Klin. Wchnschr., 1928, 1854; 

 Gyromorpha musculi Dinger, Nederl. 

 tiidschr. geneesk., 72, 1928, 5905.) From 

 Greek, coccus-shaped. 



In stained blood films these organisms 

 appear as rings, coccoids and rods, the 

 majority as rings of regular outline with 

 clear centers. They are in the plasma 

 and on the red cells. Measure 0.5 to 1.4 

 microns in greatest dimension. 



Stain pale red or reddish-blue with 

 the Giemsa or the May-Griinwald-Giemsa 

 technics. Gram-negative. 



Suggested methods of multiplication 

 by binary fission, budding, development 

 of small coccoidal to annular forms. 



Cultivation: Negative results. 



Immunology : Immunological state in 

 animals that of the premunition type. 

 Latent infection in mice which is made 

 manifest by splenectomy. 



Pathogenicity : Pathogenic for white 

 mice, rabbits, white rats, wild mice, 

 usually in young animals or in splenec- 

 tomized adults. 



Source : Blood of splenectomized white 

 mice. 



Habitat: Blood of infected animals, 

 mouse louse {Polyplax serrata) and 

 probably other arthropods. 



2. Eperythrozoon ovis Neitz, Alexan- 

 der and Du Toit. (Neitz et al.. Address, 

 Biological Society, Pretoria, Mar. 15, 

 1934; from Neitz, Onderst. Jour. Vet. 

 Sci. and An. Ind., 9, 1937, 9.) From 

 Latin ovis, sheep. 



Delicate rings approximately 0.5 to 

 1.0 micron in diameter though occasion- 

 ally larger. In addition there are tri- 

 angles with rounded angles, ovoid, 

 comma, rod, dumbbell and tennis racket 

 forms. Found supra-cellularly on the 

 erythrocytes but often free. Colored 

 pale purple to pinkish-purple with 

 Giemsa's stain. Suggested mode of mul- 

 tiplication by budding. 



Cultivation: Negative results. 



Immunology : Immunological state in 

 sheep appears to be that of the premuni- 

 tion type. 



Pathogenicity : Sheep, antelopes and 

 probably goats and splenectomized calves 

 are susceptible. Dogs, rabbits and 

 guinea pigs are refractory. The distinc- 

 tive feature of Eperythrozoon ovis is its 

 ability to provoke illness in normal 

 animals without resorting to splenec- 

 tomy. 



Source : Blood of infected South Afri- 

 can sheep. 



Habitat: Blood of infected animals. 

 No ectoparasites found on sheep naturally 

 infected, but an arthropod is suspected. 



3. Eperythrozoon wenyonii Adler and 

 Ellenbogen. (Adler and Ellenbogen, 

 Jour. Comp. Path, and Therap., ^7, 1934 

 (Sept. 3), 220; see Bartonella wenyoni in 

 appendix.) Named for Dr. C. M. Wen- 

 yon, a student of these organisms. 



Morphologically similar to Eperythro- 

 zoon coccoides. Coccoid and often vesi- 

 cular, staining pale red with Giemsa's 

 stain and varying from 0.2 to 1.5 microns 

 in diameter. Multiplication seems to 

 be by budding and fission, and by filamen- 

 tous growths from the ring forms, suggest- 

 ing resemblance to Hyphomyceles. Up 

 to 50 or 60 parasites are found on one cell. 

 These are arranged in irregular chains or 

 in tightly packed groups. 



Cultivation not reported. 



Immunology : The organism creates a 

 state of premunition and latent infection 

 is made manifest by splenectomy. 



Pathogenicity : Cattle are susceptible, 

 but sheep are not infected either before 

 or after splenectomy. 



Source: Blood of infected cattle. 



Habitat : Blood of infected cattle, 

 arthropod transmission not proven. 



4. Eperythrozoon varians Tyzzer. 

 (Proc. Amer. Philos. Soc, 85, 1942, 387.) 

 From Latin varians, varying. 



