88 



THE TRICHOMONADS 



of T. siiis, isolated by Hammond and 

 Leidl from the ceca of pigs in Germany 

 and Utah, respectively. Using both the 

 tube agglutination and precipitin tests and 

 especially the gel diffusion precipitin test, 

 she found considerable cross-reaction be- 

 tween the 4 strains. All had the same 

 major protein antigens, but they shared 

 their major polysaccharide antigens only 

 partially. The 2 bovine strains were 

 readily distinguished from each other, 

 while the 2 porcine strains were very 

 closely related but not identical. The por- 

 cine strains were more closely related to 

 the Belfast than to the Manley strain of T. 

 foetus. Robertson concluded that the 

 serologic distinctions between the 4 strains 

 did not justify separating them into 2 spe- 

 cies, and she called them all T. foetus. 



Diagnosis : Altho the mucus aggluti- 

 nation test and a number of other sero- 

 logical procedures have been suggested 

 for diagnosing T. foetus infections, the 

 only sure method is to demonstrate the 

 protozoa microscopically either directly 

 or in culture. Diagnostic procedures have 

 been described by Hammond and Bartlett 

 (1945), Morgan (1945), Bartlett (1949), 

 Fitzgerald et at. (1952) and Thorne, Shupe 

 and Miner (1955), among others. 



In heavy infections, particularly of 

 females, the trichomonads can be seen 

 by direct examination of mucus or exudate 

 from the vagina or uterus, amniotic or 

 allantoic fluid, fetal membranes, placenta, 

 fetus stomach contents, oral fluid or other 

 fetal tissues, or, in bulls, of washings 

 from the preputial cavity and rarely sem- 

 inal fluid or semen. If trichomonads can- 

 not be found on direct microscopic exam- 

 ination, cultures should be made in 

 CPLM, BGPS or Diamond's media (see 

 below). 



Samples can be obtained from the 

 vagina by washing with physiological salt 

 solution in a bulbed douche syringe. They 

 can be obtained from the preputial cavity 

 with a cotton swab or, better, by washing 

 with physiological salt solution in a bulbed 

 pipette or syringe. The washings should 

 be allowed to settle for 1 to 3 hours or 

 centrifuged before examination. 



The external genitalia should be cleaned 

 thoroughly before the samples are taken in 

 order to avoid contamination with intestinal 

 or coprophilic protozoa which might be mis- 

 taken for T. foetus. Among these are 

 Tritrichomonas enteris, Monocercotnonas 

 noninaniiuni, Protriclwmonas niminantiutn, 

 Bodo foetus, B. glissans, Spiromonas 

 atigusta, Cercomonas crassicauda, Poly- 

 tonia uvella, Monas obliqua and Lenibus 

 pusillus. In identifying T. foetus, ii must 

 be distinguished from these. 



Trichomonads are most numerous in 

 the vagina 2 to 3 weeks after infection. 

 Their numbers fluctuate in bulls, the in- 

 terval between peaks being 5 to 10 days 

 (Hammond et at. , 1950). 



A single examination is not sufficient 

 to warrant a negative diagnosis. A cow can 

 be considered uninfected if, after at least 3 

 negative examinations, she has 2 normal 

 estrus periods and subsequently conceives 

 and bears a normal calf; she should be bred 

 by artificial insemination to avoid infecting 

 the bull. A bull can be considered negative 

 if, after at least 6 negative examinations at 

 weekly intervals, he is bred to 2 or more 

 virgin heifers and they remain negative. 



Cultivation : T. foetus can be readily 

 cultivated in a number of media. Among 

 them are CPLM (cysteine-peptone-liver ex- 

 tract-maltose-serum) medium (Johnson and 

 Trussell, 1943), BGPS (beef extract-glu- 

 cose-peptone-serum) medium (Fitzgerald, 

 Hammond and Shupe, 1954) and Diamond's 

 (1957) trypticase -yeast extract-maltose- 

 cysteine-serum medium. 



T. foetus was first cultivated in tissue 

 culture by Hogue (1938). It was cultivated 

 in the chorio-allantoic sac of chicken em- 

 bryos by Nelson (1938) and independently 

 by Levine, Brandly and Graham (1939) and 

 Hogue (1939). 



Treatment: Since trichomonosis is 

 ordinarily self-limiting in females, treat- 

 ment is unnecessary. No satisfactory 

 treatment is known for these infections. 



Many investigators have reported on 

 treatment of T. foetus infections in bulls, 



