92 



THE TRICHOMONADS 



lasted 3 to 42 days. Fitzgerald el al. 

 (1958) produced nasal and cecal infections 

 in young pigs with cultures of T. suis from 

 the pig nose, and they produced nasal, gas- 

 tric and cecal infections with T. sicis from 

 the pig stomach and from the pig cecum. 



Shaw and Buttrey (1958) were able to 

 infect young chickens with T. siiis from 

 the pig nose by rectal inoculation but not 

 by mouth. 



Kerr (1958) found that the vaginal 

 mucus agglutination test of heifers infected 

 with T. suis was positive with T. suis and 

 Belfast strain T. foetus antigens but not 

 with Manley strain T.fuelus antigen. 

 Sanborn (1955) found by microagglutination 

 tests that a strain of T. suis from the pig 

 nose was antigenically different from a 

 strain of T. foetus and that both differed 

 from a pig cecal trichomonad. 



As mentioned above under the discus- 

 sion of T. foetus, Robertson (1960) found 

 that the Belfast and Manley strains of T. 

 foetus and Strains S2 and 414 of T. suis 

 were serologically related and concluded 

 that the differences between them did not 

 justify separating them into 2 species. 



Cattle and swine are often raised to- 

 gether, and the broad host ranges and mor- 

 phologic, metabolic and serologic similar- 

 ity between T. suis and T. foetus suggest 

 that they may have had a common origin if 

 they are not indeed the same. Robertson 

 (1960) believed that they are the same and 

 called them all T. foetus, but the correct 

 name, as Hibler et al. (1960) pointed out, 

 would be T. suis. Even so, however, it 

 might still be worth-while to retain both 

 names, simply as a matter of convenience. 



TRITRICHOMONAS ROTUNDA 

 HIBLER, HAMMOND, CASKEY, 

 JOHNSON AND FITZGERALD, 1960 



Synonym : Tritrichomonas suis pro 

 parte. 



Common Name : Medium -sized pig 

 cecal trichomonad. 



Disease : None. 



Hosts: Pig. 



Location : Cecum, colon. 



Geographic Distribution : This spe- 

 cies has been recognized so far only in 

 North America, but presumably occurs 

 thruout the world. 



Prevalence : Hibler et al. (1960) 

 found T. rotunda in the ceca of 10. 5% of 

 496 pigs in Utah. 



Morphology : This species was des- 

 cribed in detail by Hibler et al. (1960) and 

 by Buttrey (1956); the latter referred to it 

 as "T. s«/s -like." T. rotunda is typically 

 broadly piriform, and only occasionally 

 ovoid or ellipsoidal. It measures 7 to 11 

 by 5 to 7 (i with a mean of 9. by 5. 8 p. . 

 Hibler et al. saw no cytostome. Cyto- 

 plasmic inclusions were frequently pres- 

 ent. The 3 anterior flagella are about 

 equal in length, being 10 to 17/j. long with 

 a mean of 14.9|j,, and terminate in a knob 

 or spatulate structure. The blepharoplast 

 appears to consist of a single granule. 

 The undulating membrane is relatively 

 low. It and the costa extend about 1/2 to 

 2/3 of the length of the body according to 

 Hibler et al. (the full length of the body, 

 according to Buttrey), and its undulation 

 pattern varies from smooth to tightly 

 telescoped or coiled waves (with 3 to 5 in- 

 distinct folds, according to Buttrey). The 

 accessory filament impregnates heavily 

 with silver. The posterior free flagellum 

 is generally shorter than the body. The 

 axostyle is a narrow, straight, non-hya- 

 line rod with a crescent- or sickle-shaped 

 capitulum. It extends a relatively long 

 distance beyond the body (0. 6 to 6. 3 /i with 

 a mean of 4. 3fi). There is no chromatic 

 ring at its point of exit from the body. 

 The nucleus is practically spherical, 2 to 

 3 fi in diameter, with an endosome sur- 

 rounded by a clear halo. The parabasal 

 body measures 2. 3 to 3. 4 by 0. 4 to 1.3/1. 

 It is composed of 2 rami which form a V; 

 each ramus has a parabasal filament. 



Pathogenesis : Non- pathogenic. 



