Common Cause Of Abortion Research Articles

Abortions in sheep caused by Salmonella Brandenburg: Pathological findings

Extract In recent years, Salmonella Brandenburg has been a common cause of abortion in sheep in areas of the South Island of New Zealand. The disease is characterised by about 5% (range <1–20%) ewes aborting, and about 50% (range 10–100%) of these ewes die (Clark et al 2004). Abortions occur from 80 days, peaking at about 100–120 days' gestation (Clark et al 2004). On some farms, cases occur over a 2–3-week period and then cease (the typical bell-shaped curve), whereas on other farms, cases keep on occurring until lambing starts (Smart 2000, non-peer-reviewed).

Bovine abortion: aetiology and investigations

ABORTION in cattle is a significant cause of reproductive wastage and is of economic importance as a single abortion event in a dairy herd is estimated to cost £me abortions...

Veterinary and medical aspects of abortion in Danish sheep

The Danish sheep population totals around 144,000 animals, but little is known of the causes and prevalance of diseases. This study focuses on the causes of abortion in Danish sheep. During one breeding season, aborted foetuses and stillbirths with signs of intrauterine death or malformation were submitted for laboratory examination from a population of 3,758 breeding ewes. Samples from 24 incidents of abortion and 21 ewes delivering malformed lambs or lambs with ante partum decomposition were submitted. A specific aetiology was established in 66.7% and 14.3% of the cases, respectively. Bacterial pathogens were the most prevalent cause of abortion. Several of the abortifacients were zoonotic microorganisms, for example Listeria monocytogenes, Campylobacter fetus subsp. fetus, Yersinia pseudotuberculosis and Toxoplasma gondii. The identified microorganisms probably represent the most common causes of abortion in Danish sheep but occurrence in Denmark of other pathogens such as Coxiella burnetii and Chlamydophila abortus cannot be excluded. Due to the high prevalence of zoonotic microorganisms, precautions must be taken in handling abortions or assisting lambing, especially for pregnant women.

Toxoplasmosis the most common cause of abortion in Scottish sheep flocks

Toxoplasmosis most commonly diagnosed as the cause of infectious abortion in sheep in Scotland Pneumonia in suckled calves at grass Abortion storm associated with Neospora caninum in dairy cattle Nematodirosis in lambs Polyarthritis due to Streptococcus dysgalactiae in neonatal lambs Typhlocolitis in pigs associated with Brachyspira pilosicoli infection Salmonella Typhimurium in racing pigeons – These are among matters discussed in the disease surveillance report for May from Scottish Agricultural College Veterinary Services (SAC VS)

Microarray-based identification of bacteria in clinical samples by solid-phase PCR amplification of 23S ribosomal DNA sequences.

The rapid identification of the bacteria in clinical samples is important for patient management and antimicrobial therapy. We describe a DNA microarray-based PCR approach for the quick detection and identification of bacteria from cervical swab specimens from mares. This on-chip PCR method combines the amplification of a variable region of bacterial 23S ribosomal DNA and the simultaneous sequence-specific detection on a solid phase. The solid phase contains bacterial species-specific primers covalently bound to a glass support. During the solid-phase amplification reaction the polymerase elongates perfectly matched primers and incorporates biotin-labeled nucleotides. The reaction products are visualized by streptavidin-cyanine 5 staining, followed by fluorescence scanning. This procedure successfully identified from pure cultures 22 bacteria that are common causes of abortion and sterility in mares. Using the on-chip PCR method, we also tested 21 cervical swab specimens from mares for the presence of pathogenic bacteria and compared the results with those of conventional bacteriological culture methods. Our method correctly identified the bacteria in 12 cervical swab samples, 8 of which contained more than one bacterial species. Due to the higher sensitivity of the on-chip PCR, this method identified bacteria in five cervical swab samples which were not detected by the conventional identification procedure. Our results show that this method will have great potential to be incorporated into the routine microbiology laboratory.

Brucella abortus RB51 induces protection in mice orally infected with the virulent strain B. abortus 2308.

Brucellae are gram-negative, facultative intracellular bacteria which are one of the most common causes of abortion in animals. In addition, they are the source of a severe zoonosis. In this trial, we evaluated the effect of oral inoculation of Brucella abortus RB51 in mice against a challenge infection with B. abortus 2308. First, we showed that a gastric acid neutralization prior to the oral inoculation contributed to a more homogeneous and consistent infection with both vaccine strain B. abortus RB51 and virulent strain B. abortus 2308. Successively, we assessed the clearance and the immune response following an oral infection with B. abortus RB51. Oral inoculation gave a mild infection which was cleared 42 days after infection, and it induced a delayed humoral and cell-mediated immune response. Finally, we immunized mice by oral inoculation with B. abortus RB51, and we challenged them with the virulent strain B. abortus 2308 by an oral or intraperitoneal route 42 days after vaccination. Oral inoculation of B. abortus RB51 was able to give protection to mice infected with the virulent strain B. abortus 2308 by the oral route but not to mice infected intraperitoneally. Our results indicate that oral inoculation of mice with B. abortus RB51 is able to give a protective immunity against an oral infection with virulent strains, and this protection seems to rely on an immune response at the mucosal level.

Neospora caninum

Neospora caninum, a protozoal parasite, is a common cause of abortion in dairy cattle in North America. Cows that become infected with Neospora appear to remain infected for life. Infection is acquired through vertical transmission (dam to offspring in utero) or horizontal transmission and leads to endemic abortion, with occasional herds reporting abortion storms or outbreaks.2 In addition to the reproductive consequences of infection, in one study of a single large herd, seropositive primiparous animals produced 3.6 lbs less fat-corrected milk than did their seronegative primiparous herd mates.3 The objective of this study was to examined the effect of serologic status for Neospora on production in a large random sample of cattle in eastern Canada.

Gestational Psittacosis

In Europe, Chlamydia psittaci is a relatively common cause of abortion in sheep and other mammals. Psittacosis in humans is typically described as a mild-to-moderate flu-like illness. If psittacosis is acquired during pregnancy, it can present as a severe, progressive, febrile illness, with headache, disseminated intravascular coagulation, abnormal liver enzyme studies, and impaired renal function. Only cases with significant fetomaternal morbidity and mortality have been reported. Recovery from this disease follows termination of pregnancy and appropriate antibiotic therapy. Direct exposure of gravid humans to infected products of conception is the most commonly reported mode of transmission. Diagnosis is suggested by the placental histopathologic findings, which consist of an intense, acute intervillositis, perivillous fibrin deposition with villous necrosis, and large irregular basophilic intracytoplasmic inclusions within the syncytiotrophoblast. Commercially available genus-specific monoclonal antichlamydial antibody is available for the rapid confirmation of the diagnosis. In the United States, only two cases of gestational psittacosis have been previously reported. In contrast to the experience in Europe, both cases were associated with psittacine birds. This is the first reported instance of ovine-related gestational psittacosis documented in the United States. Gravid patients should be warned to avoid contact with sheep and their products, particularly during the spring lambing period.

Bovine Abortion Due to a Neospora-like Protozoan

A protozoan closely related to Neospora caninum, which until more fully characterized is usually referred to as a Neospora-like protozoan, was recently demonstrated to be the most common cause of abortion in dairy breed bovine fetuses submitted to the South Dakota Animal Disease Research and Diagnostic Laboratory (SDADRDL).10 The purpose of this report is to briefly review Neospora-like protozoan as a cause of bovine abortion and to discuss the cases submitted to the SDADRDL.

Neospora-like protozoan infection as a cause of abortion in dairy cattle.

In 1989,29 of 240 drylot Holstein cows from a New Mexico dairy aborted over a 5-month period. Seven of the 9 fetuses examined had multifocal necrotizing encephalitis and multifocal myocarditis. Neospora-like protozoa were found in tissues from 3 of the fetuses. More recently, a protozoan that reacted positively with anti-N. caninum serum was identified as the most common cause of abortion in California dairy cattle. 1,2 Many of these abortions were epizootic, with multiple abortions over a 1 or 2-month period. 1 Abortions and congenital infections in calves infected by a Neosporalike protozoan have been reported in the United States, but these were isolated cases involving only a single calf in each herd. This protozoan has never been isolated, so its exact identity remains unknown. Recent studies indicate that the organism is closely related to N. caninum, but some ultrastructural and antigenic differences exist between the bovine parasite and N. caninum isolated from dogs. Except for a single case of abortion in a beef cow from Maryland, the cases of fetal and congenital neosporosis previously reported from the United States are from the western states of New Mexico, 11 Califomia and Washington. Nineteen additional cases of bovine abortion associated with Neosporalike infection that were submitted to the South Dakota Animal Disease Research and Diagnostic Laboratory (SDADRDL) are herein reported. Specimens from cases of bovine abortions that are submitted to the SDADRDL undergo a routine protocol of testing to determine the cause of the abortion. Entire animals are necropsied and samples of brain, heart, lung, liver, kidney, placenta, tissues with gross lesions, and, since February 1991, skeletal muscle are fixed for histopathologic examination. Abomasal fluid is cultured for aerobic and microaerophilic bacteria and fungi. Scrapings of placenta are digested with potassium hydroxide and examined for fungal hyphae by a direct, nonspecific fluorescent antibody (FA) technique. If hyphae are found, the placenta is cultured for fungi. Impression smears of kidney are examined by a direct FA technique for 6 serovars of Leptospira. Direct FA tests are performed on frozen sections of kidney and spleen for infectious bovine rhinotracheitis (IBR) virus and bovine viral diarrhea (BVD) virus. Pools of brain, lung, liver, kidney, and spleen are homogenized and inoculated onto primary cultures of fetal bovine lung and turbinate cells for virus isolation. When received, a homogenate of placenta is inoculated by itself onto the same cell lines. Formalin-fixed paraffin-embedded

Two cases of hydatidiform degeneration of the placenta with fetal abnormality and triploid chromosome constitution.

SummaryTriploidy is a fairly common cause of abortion in the first trimester. It is uncommon for such a pregnancy to continue beyond this time. Two cases of triploidy with hydatidiform degeneration of the placenta and fetal abnormality where the pregnancies continued to 29 and 25 weeks are reported. The concentration of HCG in these abnormal placentae was high and the patients excreted larger than normal amounts of it. Severe pre‐eclampsia and anaemia occurred. Other cases in the literature are reviewed.

Human vibriosis caused by vibrio fetus.

Contagious abortion in cattle has been of serious concern to breeders of livestock for centuries. In 1897, Bang 1 reported that he had recovered the etiological agent, which was later designated as Brucella abortus. McFadyean and Stockman 2 confirmed this observation in England shortly thereafter, but they pointed out that not all instances of contagious abortion could be ascribed to Brucella organisms. They also incriminated a species of Vibrio known as Vibrio fetus as a cause of bovine abortion, and especially of abortion in sheep. In a series of investigations instituted later by Smith 3 in the United States, V. fetus was also found to be a common cause of abortion in cattle. Smith 4 described the characteristics of the micro-organisms in detail. In the United States, vibriosis in cattle is now looked upon as a common cause of abortion and may possibly equal, if not exceed, brucellosis in economic

THE RH FACTOR IN ABORTION

1 x THE literature on the clinical importance of the Rh factor there are many intimations that this factor in the blood is a relatively common cause of abortion. However, only Schwartz and Levine and Javert discussed this possibility in detail. Levine noted that t,he blood of only one in nine women who had experienced two or more spontaneous abortions was Rh negative. Javert studied twelve cases of habitual abortion (number of pregnancies not stated) and found the blood of nine (75 per cent) of the women concerned to be Rh positive. He concluded that “unless additional evidence shows the contrary, early habitual abortions should not be attributed to (Rh factor) iso-immunization.”

The Rh factor in abortion

1 x THE literature on the clinical importance of the Rh factor there are many intimations that this factor in the blood is a relatively common cause of abortion. However, only Schwartz and Levine and Javert discussed this possibility in detail. Levine noted that t,he blood of only one in nine women who had experienced two or more spontaneous abortions was Rh negative. Javert studied twelve cases of habitual abortion (number of pregnancies not stated) and found the blood of nine (75 per cent) of the women concerned to be Rh positive. He concluded that “unless additional evidence shows the contrary, early habitual abortions should not be attributed to (Rh factor) iso-immunization.”