A pregnant mouse model for bovine Tritrichomonas foetus infection

The economically important effects of Tritrichomonas foetus infection in cattle are abortion and infertility, yet there has not been an animal model to examine the parasite-host interactions during gestation. In this study, 5- and 7- to 8-week-old BALB/cAnNCr, BALB/cJ, and SCID/NCr mice on a BALB/c background were intravaginally infected with T. foetus. All BALB/cAnNCr and BALB/cJ mice, and 89% of SCID/NCr mice sustained infections for 13 weeks, if inoculated before 5 weeks of age. Infection rates were lower in all mouse strains inoculated at 7 weeks of age, although BALB/cAnNCr mice were significantly more susceptible than BALB/cJ or SCID/NCr mice. Vaginal bacterial flora did not account for the variation in mouse-strain susceptibility, although coagulase-negative staphylococci in vaginal flora were associated with failure of T. foetus to infect. As with infected cattle, T. foetus-specific vaginal immunoglobulin (Ig) G and IgA antibodies were elevated after infection. The number and viability of day-10 fetuses were reduced in mice infected at 5 weeks of age and bred 12 weeks after infection. Lesions in pregnant and nonpregnant infected mice, including suppurative and eosinophilic vaginitis; cervicitis; endometritis with distension of the uterine lumen; endometrial ulceration; and glandular ectasia, with neutrophils in the glandular lumen and loss of gland epithelium, were similar to those in cattle. The decidua and placenta were multifocally necrotic. Immunohistochemistry demonstrated trichomonads in vaginal folds and uterine glands, and adjacent to fetal tissues. In summary, experimentally infected BALB/cAnNCr mice showed many pathologic similarities to cattle and may serve as a model to study host-trichomonad interactions.     

The effects of bovine viral diarrhoea-mucosal disease (BVD) virus on the ovine foetus

Bovine viral diarrhoea-mucosal disease (BVD) virus has been incriminated as a cause of abortion, hairy birth coat and unthriftiness in sheep. Intravenous inoculation of 40 ewes 34 to 45 days pregnant with the V/TOB strain of virus produced death in two of four foetuses 9 days after inoculation and in all but one of 31 foetuses between 11 and 56 days. The highest levels of virus in placentomes and foetal tissues occurred between 9 and 15 days after inoculation and in foetal fluids between 11 and 18 days. Virus was not detected in any foetus later than 21 days after inoculation. Groups of 10 ewes infected between 59 and 62 days (Group B) and 70 and 76 days (Group C) of gestation had 73% and 62%, respectively, of abortions or perinatal foetal deaths. Birth weights of lambs born to infected ewes in groups B and C were significantly lower than those born to uninfected control ewes. Virus was recovered consistently from the cotyledons of the foetal membranes of live lambs, and irregularly from the tissues of full term foetuses that were dead at birth but on no occasion from mummified foetuses. There were no specific gross or microscopic lesions in tissues selected from aborted foetuses and the results highlight the difficulties associated with the diagnosis of BVD abortions and perinatal death of foetuses under field conditions.     

Tritrichomonas foetus damages bovine oocytes in vitro

Tritrichomonas foetus is an extracellular parasite of the urogenital tract in cattle. It causes infertility and abortion, but there is no documented information on the susceptibility of bovine oocytes to the parasite, except by one article that claimed no effects of T. foetus on oocytes or embryos. The aim of the present study was to study the effects provoked by T. foetus when in interaction with bovine oocytes. Oocytes were obtained from cow ovaries and divided into two groups: (1) one group contained cumulus cells, whereas (2) a second group was denuded from these cells. Light microscopy, video microscopy and scanning electron microscopy (SEM) revealed that exposure of oocytes to T. foetus caused rapid adhesion of the trichomonads to cumulus cells and to the zona pellucida (ZP). Motile parasites were observed for 12 h. The ZP was completely damaged, and the parasites were able to infiltrate beneath the ZP and reached the oocytes directly when the oocytes were denuded of the cumulus cells. Both the oocytes and the cumulus cells exhibited morphological characteristics compatible with apoptosis after interaction with T. foetus, such as chromatin condensation, the presence of several cytoplasmic vacuoles, with intact cellular membranes and organelles. The results from this study demonstrate that when a large number of T. foetus interacts with oocytes in vitro damage and apoptosis are provoked in the cow's reproductive cells. The behavior of this parasite as one of the causes of cattle infertility is discussed.     

Diagnosis and control of Vibrio foetus infection in the bovine

Extract

During the past thirty years Vibrio foetus infection in cattle has been reported from most countries of the world. Sporadic abortions, usually in mid-gestation, have been accepted until recently as the most important aspect of the infection. Of late years, however, it has become apparent that V. foetus can be responsible also for poor conception rates-associated probably with early embryonic mortality. It has been shown further that V. foetus can be transmitted not only by the bull at the time of service but also in semen used for artificial in semi nation.     

Mechanisms of Tritrichomonas foetus Pathogenicity in Cats with Insights from Venereal Trichomonosis

Almost 20 years has passed since trichomonosis was first recognized as a potential cause of diarrhea in domestic cats. Despite progress in confirming disease causation, developing means for diagnosis, and identifying approaches to treatment of the infection, we still know very little about how this parasite causes diarrhea. With increasing recognition of resistance of trichomonosis to treatment with 5‐nitroimidazole drugs, new treatment strategies based on an understanding of disease pathogenesis are needed. In this review, lessons learned from the pathogenesis of venereal trichomonosis in people and cattle are applied to clinical observations of trichomonosis in cats in effort to generate insight into areas where further research may be beneficial.     

Suspected Sarcocystis infection in an aborted bovine foetus

Extract

Sir:- Samples from a case of sporadic abortion, two weeks before term in a two-year-old heifer, were submitted to the Palmerston North Animal Health Laboratory. They consisted of fresh foetal stomach contents, fixed foetal lung, and maternal urine and serum. No significant pathogens were isolated from the stomach contents or urine and serological tests for brucellosis and leptospirosis were negative.     

Characterization of Tritrichomonas foetus antigens, using bovine antiserum

Tritrichomonas foetus antigens were identified, using the serum of an Angus heifer that had been repeatedly immunized with suspensions of 1 X 10(8) organisms in Freund's complete adjuvant. Antibody activity against T foetus was determined by dot-blot analysis, using horse-radish peroxidase-conjugated anti-bovine immunoglobulin to detect bound antibody. The antiserum contained antibodies against surface and flagellar components of live or fixed T foetus, as determined by use of immunofluorescence. The antiserum reacted with approximately 38 proteins in a pool of 55 to 60 components resolvable by polyacrylamide-gel electrophoresis of T foetus extracts.     

On the parafollicular cells in the thyroid gland of the bovine foetus

The thyroids of 117 bovine foetuses were studied by some histochemical and selective staining methods with respect to the occurrence of parafollicular cells. Furthermore, 7 foetuses were studied by electron microscopy. The length of the foetuses varied from 6 to 72 cm corresponding to an estimated age of about 2 to 9 months. Parafollicular cells were observed in the thyroids of all foetuses examined. The ultrastructure of the parafollicular cells in the foetuses differed very little from that described in adult animals. Histochemically, Luxol fast blue positive phospholipids and α-glycerophosphate dehydrogenase activity could be observed in the cells. The Solcia-Sampietro method gave positive results in most of the foetuses examined. The reactions observed at light microscopic level were rather faint in the youngest foetuses. The functional aspects of the results are discussed.     

Some antigenic and cultural properties of border disease and bovine viral diarrhoea viruses

In vitro comparison of the replication cycles of three strains of border disease virus and one strain of bovine viral diarrhoea virus showed similar growth curve patterns and a tendency of cell-free virus to exceed cell-associated virus. Each virus was antigenically distinguishable from the others in cross-neutralisation tests.     

Some antigenic and cultural properties of border disease and bovine viral diarrhoea viruses

In vitro comparison of the replication cycles of three strains of border disease virus and one strain of bovine viral diarrhoea virus showed similar growth curve patterns and a tendency of cell-free virus to exceed cell-associated virus. Each virus was antigenically distinguishable from the others in cross-neutralisation tests.     

Serologic examination of aborted ovine and bovine fetal fluids for the diagnosis of border disease, bluetongue, bovine viral diarrhea, and leptospiral infections

Fetal serum from most of 994 bovine and 553 ovine aborted fetuses was tested serologically for antibodies to border disease (BD), bovine viral diarrhea (BVD), and bluetongue (BT) viruses, and to Leptospira sp., and the results were compared with the results of isolation procedures, fluorescent antibody tests (FAT), and histologic examinations of the same fetuses. Antibodies to BT virus were not found in any of the 994 bovine and 553 ovine fetuses. Antibody titers to BVD virus were present in 39 of 966 bovine fetuses tested, and BVD virus was detected in 4 of the 39. Four of 74 fetuses in which the BVD virus was detected by FAT or isolation had titers to BVD virus. Microagglutination (MAT) titers to 1 or more of 5 serovars of leptospires were present in 52 of 773 bovine fetal sera tested. Leptospires were not detected by FAT in any bovine fetuses that had leptospiral antibody titers. Leptospires were detected by FAT in 15 aborted calves, and none of these had MAT titers. Antibody titers to BD virus were present in 80 of 486 fetal lamb sera tested, and the virus was detected by FAT or isolation in 3 of the 80 fetuses. Border disease virus was detected in 14 of 486 fetal lambs tested. Twelve of the 14 were tested serologically and 3 had titers to BD virus. Leptospiral antibody titers were present in 27 of 326 ovine fetal sera tested. Leptospires were not detected in any of the 326 ovine fetuses tested by FAT.     

Pathogenicity of CL-1 chicken anemia agent.

Twelve-day-old broiler-type chickens had hemorrhagic necrotic wing tips. After 10 blind subcultures in an MDCC-MSB1 cell line, a virus (so-called chick anemia agent [CAA]) was isolated and designated CL-1 CAA. Five-day-old specific-pathogen-free chicken embryos from a commercial breeder flock that were found not to possess antibody against CAA were infected with CL-1 virus via yolk-sac injection. Many (49%) infected embryos were small and apparently had died from severe systemic hemorrhage. Hatched chicks were small and had pale feathers, skin, skeletal muscles, bone marrow, and viscera. All infected chicks had small thymuses. These thymuses often were so small that they could not be found grossly (P = 0.002). Anemia occurred within 4 days post-hatch. Microscopically, all hematopoietic organs were markedly atrophic. Septic necrotizing lesions were seen only in organs from CL-1-injected chicks. Physicochemical and pathological characteristics of this virus indicate that it is similar to other isolates of CAA found in Europe and Japan.     

鸭源新城疫病毒对鹅的致病性试验

鸭源新城疫病毒（NDV）SDFC株通过静脉注射、肌肉注射、点眼滴鼻3种途径人工感染15日龄健康雏鹅,观察试验鹅的发病情况及临床症状,于感染后不同时间剖杀,观察各组织器官的主要剖检变化,并进行病理组织学研究,同时对病毒在组织中的抗原分布进行检测。结果显示,试验鹅感染鸭源NDV后发病率达100%,静脉注射组死亡率为80%,肌肉注射组死亡率为40%,点眼滴鼻组死亡率为26.7%。病鹅表现下痢、流泪,部分出现瘫痪、扭头、角弓反张等神经症状;剖检变化表现为胰腺、脾脏有大小不等的白色坏死灶,胸腺、法氏囊萎缩,心包积液,肠道、肝脏、肺脏、肾脏出血;病理组织学变化表现为胸腺、脾脏、法氏囊等器官内淋巴细胞坏死、崩解,心脏、肺脏、肝脏、肾脏广泛性出血、变性;抗原分布检测结果显示,病毒在病鹅体内多个组织器官中分布。试验结果表明,鸭源NDV对鹅具有较强的致病性。