Campero C M, Rodriguez Dubra C, Bolondi A, Cacciato C, Cobo E, Perez S, Odeon A, Cipolla A, BonDurant R H
Instituto Nacional de Tecnologia Agropecuaria, INTA, Patologia Veterinaria, CC276 (7620), Balcarce, Argentina.
Vet Parasitol. 2003 Mar 10;112(3):167-75. doi: 10.1016/s0304-4017(02)00423-5.
Preputial fluids from 567 virgin Angus and Hereford bulls, 1-2 years old, were inoculated into Sutherland medium, and approximately 8.4% produced cultures with a protozoan suggestive of Tritrichomonas foetus. Under brightfield microscopy, large numbers of single-celled motile organisms with multiple anterior flagellae, a posterior flagellum, axostyle, and a visible undulating membrane were detectable. Motility was jerky and rolling, as described for T. foetus. Air-dried smears of cultures stained with Giemsa or Diff-Quick + iodine revealed an organism similar to T. foetus, although somewhat more rounded. Several organisms appeared to have four anterior flagellae. Scanning electron microscopy (5000x) of representative samples revealed four anterior flagellae on most organisms, and an axostyle that was consistently longer than that seen in T. foetus. Using pan-trichomonal primers and T. foetus-specific primers in a polymerase chain reaction (PCR) assay, amplification products of 372bp were detected in all virgin bull isolates, but only with the pan-trichomonal primers. Positive control isolates of T. foetus yielded amplification products of the expected size (372 and 347bp) with the two sets of primers, respectively. We conclude that these protozoa are not T. foetus, and note the similarity of these findings with those reported earlier in North American beef cattle. Because in several countries there is no legal treatment for bovine trichomonosis, veterinarians recommend slaughter of bulls with positive preputial cultures. The existence of easily mis-identified non-T. foetus trichomonads in the bovine prepuce suggests that the current "gold standard" diagnostic test (culture of preputial scrapings or washings) should be augmented with a more specific confirming test, such as the PCR employed in this study.
将567头1 - 2岁的未交配安格斯和赫里福德公牛的包皮液接种到萨瑟兰培养基中，约8.4%的样本培养出了一种原生动物，疑似胎儿三毛滴虫。在明视野显微镜下，可检测到大量单细胞活动生物体，具有多条前鞭毛、一条后鞭毛、轴柱和可见的波动膜。其运动为急促且滚动式，与胎儿三毛滴虫的描述一致。用吉姆萨或Diff-Quick +碘染色的培养物空气干燥涂片显示出一种与胎儿三毛滴虫相似的生物体，不过略显更圆。一些生物体似乎有四条前鞭毛。代表性样本的扫描电子显微镜（5000倍）观察显示，大多数生物体有四条前鞭毛，且轴柱始终比胎儿三毛滴虫中的更长。在聚合酶链反应（PCR）检测中，使用泛三毛滴虫引物和胎儿三毛滴虫特异性引物，在所有未交配公牛分离株中均检测到372bp的扩增产物，但仅使用泛三毛滴虫引物时能检测到。胎儿三毛滴虫的阳性对照分离株分别用两组引物产生了预期大小（372bp和347bp）的扩增产物。我们得出结论，这些原生动物不是胎儿三毛滴虫，并注意到这些发现与北美肉牛早期报道的相似。由于在几个国家，牛滴虫病没有合法的治疗方法，兽医建议对包皮培养阳性的公牛进行屠宰。牛包皮中存在容易被误认的非胎儿三毛滴虫表明，当前的“金标准”诊断测试（包皮刮屑或冲洗液培养）应以更特异的确认测试（如本研究中使用的PCR）加以补充。
