Infectious Causes Of Abortion Research Articles

Immunogenicity, safety and dual DIVA-like character of a recombinant candidate vaccine against neosporosis in cattle

Neosporosis is the major infectious cause of abortion and reproductive losses in cattle worldwide; however, there are no available vaccines or drugs to control this disease. Recently, a dual (positive and negative) DIVA-like (Differentiation of Infected from Vaccinated Animals) vaccine was evaluated in a pregnant mouse model of neosporosis, showing promising immunogenic and protective results. The current report aimed to study the safety, the dose-dependent immunogenicity and the dual DIVA-like character of a recombinant subunit vaccine composed of the major surface antigen from Neospora caninum (rNcSAG1) and the carrier/adjuvant Heat shock protein 81.2 from Arabidopsis thaliana (rAtHsp81.2) in cattle. Healthy heifers were separated and assigned to experimental groups A-F and subcutaneously immunized with 2 doses of vaccine formulations 30 days apart as follows: A (n=4): 50 μg rNcSAG1 + 150 μg rAtHsp81.2; B (n=4): 200 μg rNcSAG1 + 600 μg rAtHsp81.2; C (n=4): 500 μg rNcSAG1 + 1,500 μg rAtHsp81.2; D (n=3): 150 μg rAtHsp81.2; E (n=3):1,500 μg rAtHsp81.2, and F (n=3) 2 ml of sterile PBS. The immunization of heifers with the different vaccine or adjuvant doses (groups A-E) was demonstrated to be safe and did not modify the mean value of the evaluated serum biomarkers of metabolic function (GOT/ASP, GPT/ALT, UREA, Glucose and total proteins). The kinetics and magnitude of the immune responses were dose-dependent. The higher dose of the vaccine formulation (group C) stimulated a broad and potent humoral and cellular immune response, characterized by an IgG1/IgG2 isotype profile and IFN-γ secretion. In addition, this was the first time that dual DIVA-like character of a vaccine against neosporosis was demonstrated, allowing us to differentiate vaccinated from infected heifers by two different DIVA compliant test approaches. These results encourage us to evaluate its protective efficacy in infected pregnant cattle in the future.

Metagenetic Analysis of the Pregnant Microbiome in Horses

Placentitis is the leading cause of infectious abortion in the horse. Additionally, it can result in weak and/or growth restricted offspring. While the etiology of ascending placentitis is well described in mares, less is known regarding the pathogenesis of other types, such as nocardioform placentitis. This study aims to identify the microbial communities in different body sites of the pregnant mare in early gestation to establish a core microbiome that may be perturbed in pathologic pregnancies such as placentitis. We hypothesize that the equine placenta harbors a distinct resident microbiome in early pregnancy when characterized by metagenetics and that there will be a disparity in bacterial communities from the oral, vaginal, and fecal microbiome. Samples were collected from the oral cavity, vagina, anus, and the allantoic portion of the allantochorion (“placenta”) from five pregnant mares between 96 and 120 days of gestation. The V4 region of the 16S rRNA gene was amplified for Illumina MiSeq sequencing to examine core bacterial communities present in the different body sites. Microbial community composition of the pregnant ponies by body site was significantly different (Bray–Curtis dissimilarity). The placenta was significantly different from the feces, oral cavity, and vagina. Alpha diversity measuring the Shannon diversity matrix was significant, with the body sites being a compounding variable, meaning there was a difference in richness and evenness in the different microbial communities. Feces had the greatest alpha diversity, while the oral cavity and placenta similarly had the least. In conclusion, metagenetics did reveal distinct community differences in the oral, fecal, vaginal, and placenta cavities of the horse. The equine placenta does show similarities in its microbial communities to the oral cavity. Further research needs to be completed to investigate how bacteria may be translocated to the placenta from these other body sites and how they contribute to the development of placentitis.

Prospective cohort study reveals unexpected aetiologies of livestock abortion in northern Tanzania

Livestock abortion is an important cause of productivity losses worldwide and many infectious causes of abortion are zoonotic pathogens that impact on human health. Little is known about the relative importance of infectious causes of livestock abortion in Africa, including in subsistence farming communities that are critically dependent on livestock for food, income, and wellbeing. We conducted a prospective cohort study of livestock abortion, supported by cross-sectional serosurveillance, to determine aetiologies of livestock abortions in livestock in Tanzania. This approach generated several important findings including detection of a Rift Valley fever virus outbreak in cattle; high prevalence of C. burnetii infection in livestock; and the first report of Neospora caninum, Toxoplasma gondii, and pestiviruses associated with livestock abortion in Tanzania. Our approach provides a model for abortion surveillance in resource-limited settings. Our findings add substantially to current knowledge in sub-Saharan Africa, providing important evidence from which to prioritise disease interventions.

Histopathological analysis of placental lesions caused by Chlamydia abortus 1B vaccine strain in vaccinated ewes

Background Chlamydia abortus is one of the most diagnosed causes of infectious abortion in small ruminants. Infections can be controlled using the live, attenuated C. abortus strain 1B vaccine, which has been associated with infection and abortion in animals. This study aimed to compare the severity and the distribution of lesions caused by this vaccine strain (vt) with those resulting from a wild-type (wt) infection. Methods Two grossly affected and 1B-positive (by qPCR and RFLP analysis) placentas from a vaccinated sheep flock were analysed. Histopathological lesions and immunohistochemical labelling (IHC) were graded (increasing score from 0 to 5) according to their severity and distribution. Pathology in the vt infected placentas was compared with that in two wt infected placentas. Datasets generated for observed histological and pathological features were analysed using principal component analysis (PCA). Results Histopathologically, the lesions in both vt and wt-placentas presented as typical multifocal necrosuppurative placentitis, associated with vasculitis, mural necrosis, and thrombosis. IHC for C. abortus revealed intense staining with a multifocal distribution in most cotyledons in both vt and wt placentas. Comparison of the pathological lesions between vt and wt by PCA revealed a similar distribution and severity, revealing a strong association with features such as necrosis and inflammatory infiltration between vt and wt placentas. A weaker association with IHC was observed. Conclusion This study shows that the C. abortus attenuated 1B vaccine strain presents no significant differences in severity and distribution of pathological lesions from those typically observed following a wt infection.

Knowledge and perception of community about causes of cattle abortion and case-control study of brucellosis as cause of abortion in Jimma zone, Ethiopia.

BackgroundAbortion, causes by several infectious and non‐infectious factors is one of the most critical health problems of cattle in Ethiopia. Thus, this study aimed to assess knowledge and perception of the community about potential causes of abortion and case‐control study of brucellosis as a cause of abortion in cattle of study districts.MethodsA cross‐sectional study was conducted between October 2016 and October 2017 in selected districts of the Jimma zone using a questionnaire survey. Based on the questionnaire survey, we also carried out a case‐control study (141 cases and 282 controls) to confirm whether the most frequently mentioned disease (brucellosis) is associated with abortion. The blood samples were collected from both cases and controls cattle groups and then serum was separated. The presence of antibody against Brucella organism in serum was first tested by Rose Bengal Plate Test (RBPT) and all RBPT positive samples were confirmed using the Complement Fixation Test (CFT).ResultsFrom a total of 180 randomly selected respondents, the majority (59.4%) of them attributed abortion to infectious diseases. Based on the questionnaire survey, brucellosis, leptospirosis and listeriosis were identified as the major infectious causes of abortion in the areas. Physical injuries, shortage of feed and toxic substances were observed as less important non‐infection causes of abortion in the study areas. This study also identified improper disposal of aborted materials and birth products, use of communal bulls, sharing communal grazing areas and water sources which favour disease transmission. Exposure to Brucella organism was higher among cases (6.4%) than controls (2.8%) with a statistically significant difference (p = 0.042).ConclusionBrucellosis is the most important infectious cause of cattle abortion in this study. Thus, important to conduct appropriate control methods and increasing public awareness of the zoonotic transmission of brucellosis are suggested. This finding also recommended the need for further study to isolate and characterise brucellosis as a cause of abortion in cattle.

Clinical, pathologic, and epidemiologic features of nocardioform placentitis in the mare

Placentitis is the leading cause of infectious abortion in the horse and contributes to roughly 19% of all abortions in the United States. A type of placental infection, nocardioform placentitis (NP) is associated with gram-positive branching actinomycetes localized within the ventral body of the feto-maternal interface to create a lymphoplasmacytic mucoid lesion. While the etiology of this disease is poorly described, this placental infection continues to cause episodic abortions in addition to weak and/or growth retarded neonates. The goal of the present study was to perform a comprehensive analysis of pregnancies associated with a nocardioform-affected placenta and make inferences into the epidemiology of this elusive disease. To do so, 264 mares were enrolled in the study, with 145 as having suspected disease (n = 145; NP) either based on pregnancy-related complications or postpartum placental evaluation, while an additional 119 were enrolled as healthy pregnancies (n = 119; CON). Following diagnosis as either NP or CON based on gross and histopathology at the University of Kentucky Veterinary Diagnostic Laboratory, information was gathered on the mares and neonates for comparisons between diseased and healthy pregnancies. Clinically, a significant portion of diseased mares had clinical indications of NP, including premature mammary gland development, thickening of the placenta noted on transrectal ultrasonography, and separation between the chorioallantois and endometrium noted on abdominal ultrasonography, while vulvar discharge was not commonly noted. Additionally, NP was correlated with increased mare age, decreased gestational length, and decreased neonatal weight, although neonatal IgG and WBC were comparable to CON. Incidence of NP was not correlated with last breeding date, pre- and post-breeding therapeutics, parity, prophylactic medications, or housing. Additionally, NP did not affect postpartum fertility. While NP was associated with a poor neonatal outcome (abortion and/or growth retarded neonate), this did not appear to be influenced by the bacteria isolated (Amycolatopsis spp. vs. Crossiella equi), and mares diagnosed with NP do not appear to be infectious to other pregnant mares nor have repetitive years of the disease. Interestingly, lesion size was positively correlated with last breeding date, as mares bred later in the breeding season correlating with a larger placental lesion. In conclusion, while the etiology of NP continues to elude researchers, the epidemiology of this disease has gained clarity, providing inferences into the management of suspect mares.

Placentitis and abortion caused by a multidrug resistant strain of Campylobacter fetus subspecies fetus in a sheep in Uruguay

Campylobacter fetusfetus (Cff) is a major infectious cause of abortion in sheep worldwide, and an opportunistic human pathogen. Information on Cff as an ovine abortifacient in South America is limited. We describe a case of abortion caused by a multidrug resistant strain of Cff in a sheep in Uruguay. In August 2017, 3/57 pregnant ewes (5.3%) aborted whithin one week. Histopathologic examination of the placenta of an aborted ewe revealed severe neutrophilic and fibrinonecrotizing placentitis with vasculitis and thrombosis of the chorionic arterioles. Cff was isolated on microaerobic culture in Skirrow agar, and further confirmed by 16S rDNA PCR amplification and sequencing, and endpoint and real time PCR assays. Antimicrobial sensitivity testing revealed resistance to tetracyclines, nalidixic acid, telithromycin and clindamycin. Other abortifacients were not detected. Further studies are necessary to determine the geographic distribution, ecology, epidemiology, economic impact, and antimicrobial resistance of Cff in sheep flocks in Uruguay.

Abortion Due to Neospora caninum in Dairy Cattle in Southern Santa Catarina State, Brazil

Background: Neosporosis is a cosmopolitan disease known as the main infectious cause of abortion in cattle, reported in several states in Brazil. The transplacental transmission in cattle is responsible for perpetuating the disease in the herd. In the state of Santa Catarina, previous studies on this protozoan in cattle are mostly serological surveys. To increase information about this reproductive disorder, this work describes the diagnosis of abortions due to Neospora caninum in dairy cattle from state of Santa Catarina and the follow-up for 4 years in a farm affected by neosporosis.Case: From 2015 to 2019, necropsy was performed on 10 aborted bovine fetuses, between fifth and eighth month of pregnancy, with 1 fetus aborted in 2015, 3 in 2016, 2 in 2017 and, 4 in 2019, all originating from the same dairy property in the southern region of state of Santa Catarina. No macroscopic lesions were found. Histopathology revealed mild to moderate multifocal mononuclear necrotizing encephalitis in 5 fetuses, and multifocal mild mononuclear myositis and myocarditis in 4 and 3 fetuses, respectively. Polymerase Chain Reaction (PCR) using primers based on the Nc-5 gene was positive for N. caninum in five fetuses. Three visits were performed in the farm for epidemiological evaluation and blood samples collection for IgG antibodies anti-N. caninum (IFAT). The total herd was 170 Jersey, Holstein and crossbred cattle, raised in a semi-confined system with mechanical milking system. Since 2014, there has been a significant increase in abortions cases, approximately 20 cows had abortions; in the year 2015, approximately 10; in 2016, less than 5; in 2017, 4 cows aborted; in 2018, 11 abortions and, in 2019, there were 4 abortions. An increase in the rate of return to estrus was also reported, and both primiparous and multiparous cows had reproductive disorders. Abortions were recorded throughout the year and occurred predominantly between the fourth and sixth month of pregnancy. In 2016, an Indirect Immunofluorescence Reaction (IFAT) was performed on sera from 26 cows (13 with a history of reproductive disorders and another 13 without disorders). Of these, 50.0% (13/26) were seropositive, with titers ranging from 100 to 1600 (cutoff ≥100). The Enzyme Immunoassay (ELISA) of the entire herd was carried out in 2017, with 26.54% (43/162) of seropositivity, 8.02% (13/162) suspect, and 30.4% (17/56) had reproductive disorders. It was observed that only animals born on the property were used for replacement, there was less possibility of direct contact between dogs on the property with milking facilities, placental and fetal remains, properly disposing of these, incinerating or burying. Thirty animals were discarded from the property, 25 of which had reproductive disorders. All young female daughters of seropositive cows remained on the property for replacement. During the evaluation period, all dogs were eliminated.Discussion: In this study, the diagnosis of neosporosis was made through epidemiology, histopathological lesions characterized by mononuclear encephalitis, myocarditis and myositis, and detection of the agent by PCR, associated with serological techniques. The lesions observed are indicative of N. caninum infection and are compatible with lesions observed in other studies. Serological screening is important to complement the diagnosis of abortion by N. caninum and to help control the agent in herds. From this report it is concluded that N. caninum is an important agent of reproductive disorders in cattle in the southern region of Santa Catarina, the different serological analyzes showed a good screening index for the inclusion of control strategies. In addition, the monitoring of reproductive rates of affected properties becomes necessary over the years, allowing better observation of control strategies.Keywords: reproductive disorder, fetal death, protozoan, parasitology.Descritores: distúrbio reprodutivo, morte fetal, protozoário, parasitologia.

Toxoplasma gondii induced abortions in a goat herd in Rio de Janeiro, Brazil

ABSTRACT: Although, serological assays for detecting immune response against Toxoplasma gondii in goats and sheep are frequent in Brazil, studies showing lesions and confirmation of infectious causes of abortion in goats in the state of Rio de Janeiro have not been reported. This study aimed to describe an abortion outbreak caused by T. gondii in a goat herd in the state of Rio de Janeiro. At histological examination, necrotizing encephalitis and lymphoplasmacytic myositis were observed in goat fetuses submitted to necropsy. The diagnoses were confirmed by immunohistochemistry, which revealed positive marking structures compatible with T. gondii bradyzoites in the brain and skeletal muscle cysts. T. gondii should be included among the causes of abortion in goats in the Southeast region of Brazil.

The 1B vaccine strain of Chlamydia abortus produces placental pathology indistinguishable from a wild type infection.

Chlamydia abortus is one of the most commonly diagnosed causes of infectious abortion in small ruminants worldwide. Control of the disease (Enzootic Abortion of Ewes or EAE) is achieved using the commercial live, attenuated C. abortus 1B vaccine strain, which can be distinguished from virulent wild-type (wt) strains by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Published studies applying this typing method and whole-genome sequence analyses to cases of EAE in vaccinated and non-vaccinated animals have provided strong evidence that the 1B strain is not attenuated and can infect the placenta causing disease in some ewes. Therefore, the objective of this study was to characterise the lesions found in the placentas of ewes vaccinated with the 1B strain and to compare these to those resulting from a wt infection. A C. abortus-free flock of multiparous adult ewes was vaccinated twice, over three breeding seasons, each before mating, with the commercial C. abortus 1B vaccine strain (Cevac® Chlamydia, Ceva Animal Health Ltd.). In the second lambing season following vaccination, placentas (n = 117) were collected at parturition and analysed by C. abortus-specific real-time quantitative PCR (qPCR). Two placentas, from a single ewe, which gave birth to live twin lambs, were found to be positive by qPCR and viable organisms were recovered and identified as vaccine type (vt) by PCR-RFLP, with no evidence of any wt strain being present. All cotyledons from the vt-infected placentas were analysed by histopathology and immunohistochemistry and compared to those from wt-infected placentas. Both vt-infected placentas showed lesions typical of those found in a wt infection in terms of their severity, distribution, and associated intensity of antigen labelling. These results conclusively demonstrate that the 1B strain can infect the placenta, producing typical EAE placental lesions that are indistinguishable from those found in wt infected animals.

Detection ofCoxiella burnetiiand equine herpesvirus 1, but notLeptospiraspp. orToxoplasma gondii,in cases of equine abortion in Australia - a 25 year retrospective study.

Equine abortion is a cause of severe economic loss to the equine industry. Equine herpesvirus 1 is considered a primary cause of infectious abortion in horses, however other infectious agents can also cause abortion. Abortions due to zoonotic pathogens have implications for both human and animal health. We determined the prevalence of Coxiella burnetii, Leptospira spp. and Toxoplasma gondii in 600 aborted equine foetal tissues that were submitted to our diagnostic laboratories at the University of Melbourne from 1994 to 2019. Using qPCR we found that the prevalence of C. burnetii was 4%. The highest annual incidence of C. burnetii was observed between 1997–2003 and 2016–2018. The prevalence of C. burnetii in Victoria and New South Wales was 3% and 6% respectively. All the samples tested negative for Leptospira spp. and Toxoplasma gondii DNA. Equine herpesvirus 1 DNA was detected at a prevalence of 3%. This study has provided evidence for the presence of C. burnetii in equine aborted foetal tissues in Australia, but the role of C. burnetii as potential cause of abortion in Australia requires further investigation. C. burnetii is a zoonotic disease agent that causes the disease ‘Q fever’ in humans. We recommend that appropriate protective measures should be considered when handling material associated with equine abortions to reduce the risk of becoming infected with C. burnetii.

Combined control evaluation for Neospora caninum infection in dairy: Economic point of view coupled with population dynamics

Neospora caninum infection is regarded as one of the most important infectious causes of abortion in dairy cattle. To intervene in its spread, four potential controls including test-and-cull, medication, vaccination, and selective breeding are considered and assessed in this study. The cost of each control, together with the inevitable annual loss due to population dynamics, is adopted as an assessment criterion from an economic point of view. By performing simulation and sensitivity analysis, our results demonstrate that compared with each single control, combined controls are worthwhile with better financial outcomes. For farm affected with significant prevalence (equal to or greater than 30%), vaccine treatment is the most effective and economical option among all control strategies. On the other hand, for farm where prevalence is relatively low (around 10%), combined control, by applying vaccination followed with test-and-cull, medication or selective breeding, could be alternative treatment to provide better financial outcome against single control in an observed period.

Serology for Neosporosis, Q fever and Brucellosis to assess the cause of abortion in two dairy cattle herds in Ecuador

BackgroundDetermining the infectious cause of abortion in cattle is difficult. This case-control study was set up to investigate the infectious causes of abortion by determining the seroprevalence of three reproductive pathogens in dairy cattle in Ecuador and their association with abortion: Brucella abortus, Neospora caninum and Coxiella burnetii.ResultsNinety-five blood samples were obtained from cows that had experienced a mid- or late gestation abortion of their first calf and seventy-seven samples from a control group of cows with the same age that did not experience abortion problems. No antibodies were detected for B. abortus in any of the serum samples, but a high seroprevalence for both C. burnetii (52.9%) and N. caninum infection (21.5%) was found in group of cows. The seroprevalence of N. caninum infection in cattle that had experienced abortions was significantly higher (p < 0.05) than the seroprevalence in the control cows on one of the cattle farms, but no association between abortion and seropositivity for C. burnetii was found.ConclusionWe conclude that Neosporosis plays an important role in the epidemiology of abortion on one cattle farm, but that Q fever is apparently not an important cause for abortion in this setting.

Risk factors for reproductive disorders and major infectious causes of abortion in sheep in the highlands of Ethiopia

Community-based sheep breeding programs (CBBPs) were established in Ethiopia since 2010. Improved rams from CBBPs need to be disseminated. However, there is a risk of transmitting reproductive diseases to other community flocks. To investigate this a cross-sectional study was conducted in 2015/16 to determine serological status of major infectious causes of abortion and associated risk factors in sheep in the highlands of Ethiopia. A total of 120 households from three districts (Bonga, Horro and Menz) were enrolled in the study. Per farm, 3–4 samples of animals aged >2 years were collected. A total of 445 sera were tested for Chlamydia spp., Coxiella burnetti, Toxoplasma, Brucella spp. and Border disease virus. Poison regression was used to model the number of abortions, number of neonatal lost and number of stillbirths in the flocks. A mixed-effects logistic regression model was fitted to identify covariates associated with prevalence of infectious causes of abortion. The study found that 20% [95% CI 12.74, 27.26] of flocks had recent experience of sheep abortion, lamb losses was at 65% [95% CI 56.34,73.65] and still birth at 10% [95% CI 4.55,15.44]. The incidence risk ratio for abortion was higher in larger flocks. Neonatal losses were higher in C. burnetii and Toxoplasma gondii positive flocks, in one of the districts, and in flocks with more than 30 animals. The serological analyses revealed the presence of three abortive infections, while none of the samples tested positive for Brucella spp. or Border disease virus. Of the 120 flocks tested, 107 (89.17%) were positive for Chlamydia spp., 82 (68.33%) for C. burnetii, and 85 (70.83%) for T.gondii. The results highlight the likely contribution of different infectious agents in the reproductive disorders in sheep production in Ethiopia. The high sero-prevalence of infectious agents, especially Chlamydia spp., at both flock and animal level, warrants more in-depth research to attribute reproductive problems to these pathogens.

Seroprevalence of antibodies for bovine viral diarrhoea virus, Brucella abortus and Neospora caninum, and their roles in the incidence of abortion/foetal loss in dairy cattle herds in Nakuru District, Kenya

BackgroundNo comprehensive studies have been carried out on the infectious causes of abortion in Kenyan dairy cattle herds. A survey was carried out to determine the seroprevalence of antibodies against Bovine Viral Diarrhoea Virus (BVDV), Brucella abortus (BA) and Neospora caninum (NC) among dairy cattle herds in Nakuru County, a major dairying area in Kenya. A prospective sero-epidemiological study was also undertaken to investigate the effects of BVDV, BA and NC on the occurrence of bovine abortion in dairy cattle herds, where monthly rectal palpations for pregnancy were performed, and monthly serum samples were tested for antibodies to the 3 pathogens.ResultsIn the 398 randomly selected cattle on 64 dairy herds, the seroprevalences of antibodies to BVDV, NC and BA were 79.1, 25.6 and 16.8%, respectively. Of the cattle seropositive to NC, 83.3% were also seropositive to BVDV and 13.7% to BA. Of the cattle seropositive to BVDV, 17.1% were also seropositive to BA. Among 260 monitored pregnant dairy cattle on the same 64 dairy farms, an incidence risk for abortion of 10.8% (28/260) was identified, while the incidence of other foetal losses was 1.1% (3/260). The incidence rates of sero-conversion for NC, BVD and BA were 1.1, 0.06 and 0.5 new infections/100 cow-months at risk, respectively. The foetal losses were mainly observed in animals less than 96 months old and occurred in mid-gestation. Neospora caninum was associated with most cases (29.0%) of foetal losses, followed by mixed infections of NC and BVDV (12.9%), BVDV (9.9%) and co-infections of BA and NC (6.5%).ConclusionsThis is the first study to document the substantial incidence risk of BVDV and NC abortions in dairy cattle in Kenya, and demonstrates the relative importance of BA, BVDV and NC infections in dairy cattle in Kenya. Kenya laboratories should offer diagnostic tests for BVDV and NC to help farmers determine their roles in abortions on their farms. A comprehensive policy on the control of these important diseases should also be put in place by government with the involvement of all stakeholders in the dairy cattle industry.

Bovine Fetal Placenta During Pregnancy and the Postpartum Period.

Bovine abortion is a worldwide problem, but despite extensive histopathologic and molecular investigations, the cause of abortion remains unclear in about 70% of cases. Cellular debris is a commonly observed histopathologic finding in the fetal placenta and is often interpreted as necrosis. In this study, the nature of this cellular debris was characterized, and histologic changes in the normal fetal placenta during pregnancy and after delivery were assessed. In addition, the presence of the most common abortifacient pathogens in Switzerland ( Chlamydiaceae, Coxiella burnetii, Neospora caninum) was tested by polymerase chain reaction. We collected 51 placentomes and 235 cotyledons from 41 and from 50 cows, respectively. In total, cellular debris was present in 48 of 51 (94%) placentomes and in 225 of 235 (96%) cotyledons, inflammation occurred in 1 of 51 (2%) placentomes and in 46 of 235 (20%) cotyledons, vasculitis was seen in 1 of 51 (2%) placentomes and 46 of 235 (20%) cotyledons, and 18 of 51 (35%) placentomes and 181 of 235 (77%) cotyledons had mineralization. The amount of cellular debris correlated with areas of positive signals for cleaved caspase 3 and lamin A. Therefore, this finding was interpreted as an apoptotic process. In total, 10 of 50 cotyledons (20%) were positive for C. burnetii DNA, most likely representing subclinical infections. The results of our study indicate that histologic features in the fetal placenta such as cellular debris, inflammation, vasculitis, and mineralization must be considered physiological processes during pregnancy and after delivery. Therefore, their presence in placentae of aborted fetuses must be interpreted with caution and might not be necessarily linked to an infectious cause of abortion.

Molecular epidemiology of Campylobacter Fetus in aborted fetuses of Baluchi sheep in Sistan region

Campylobacter is one of the main bacterial causes of ewe abortion throughout the world. Campylobacter infections are now considered as zoonoses. The objective of this study was an investigation of Campylobacter fetus prevalence among aborted ovine fetuses in the Sistan region (north of Sistan and Baluchestan province). In the present study, spleen and abomasum content samples were obtained from 78 aborted lambs of Baluchi sheep. The samples were examined for campylobacter contamination using PCR method. The overall prevalence of campylobacter infection was 7.7%. The prevalence of infection in fetuses aged three months and under were significantly higher than that in fetuses older than three months. The result of this study showed that C. fetus should be considered as one of the infectious causes of abortion among sheep flocks in Sistan region.

Retrospective Biomolecular Investigation of Coxiella burnetii and Leptospira spp. DNA in Cases of Abortion, Stillbirth and Neonatal Mortality in Dogs and Cats

Abortion and neonatal mortality are events that can occur in breeding bitches and queens. It has been reported that up to 55% and 33% of these cases remain without a known cause, respectively, in canine and feline pregnancies. Unusual abortigenic and potentially zoonotic agents, including Coxiella burnetii and Leptospira spp., may be involved in these cases. C. burnetii is able to cause reproductive disorders in cattle, sheep and goats, and cases of abortion have been observed in dogs and cats. Moreover, several outbreaks of C. burnetii infection in humans have been caused by delivering bitches and queens, and some of these animals experienced abortion. Leptospira interrogans sensu lato is able to cause abortion or stillbirth in several animal species and its abortigenic role has occasionally been described in bitches and queens. The aim of this study was to search for C. burnetii and Leptospira spp. DNA in a retrospective series of 103 cases of canine and feline abortion, stillbirth, and neonatal mortality submitted for the identification of possible infectious agents. One hundred and fifty-one specimens were tested using PCR assays and found negative for C. burnetii and Leptospira DNA. However, in 49 samples (47.6%) other infectious causes of abortion, stillbirth, and neonatal mortality were identified. These results showed that C. burnetii and Leptospira spp. are probably not common abortigenic agents or causes of neonatal deaths in dogs. However, given the potential abortigentic and zoonotic role of these agents, surveillance of canine and feline abortion, stillbirth, and neonatal mortality could be advisable for a systematic investigation of these events.

A multi-screening Fast qPCR approach to the identification of abortive agents in ruminants

Abortion in ruminants represents an important economic concern for farmers. Microbial agents, such as Brucella spp., Chlamydia spp., Coxiella burnetii, Leptospira spp., Neospora caninum, Salmonella spp. and Toxoplasma gondii, are among the main infectious causes of abortion and require rapid and reliable diagnosis. This study describes the development of a multi-screening assay using Fast Real-Time PCR (Fast qPCR) that allows, in a single test, the simultaneous identification of the above-mentioned abortive agents. This multi-screening approach is characterized by a mean diagnostic sensitivity and specificity of 100% and 97%, respectively; it has a limit of detection (LOD) ranging from 5 × 103 to 4 × 104 genomic copies/g of tissue and a very good concordance with traditional end-point PCR assays used in routine diagnostic activity.The proposed method represents a rapid approach to the simultaneous detection of the main abortive agents in ruminants that allows to make an accurate diagnosis and to set up appropriate control measures in a short period of time.

Chlamydial abortion of ewes and goats. I. Current aspects on etiology, pathogenesis, immune mechanisms and epizootiology of disease

Chlamydial abortion constitutes one of the major causes of infectious abortion in sheep and goats. The disease leads to considerable losses in most sheep and goat-rearing countries, as well as, in Greece. In this paper, a review of the causative agent, pathogenesis, host immune response and epizootiology is presented. After recent changes, that have occured in the taxonomy of chlamydiae, it is necessary to refer to new families, new genera and new species within the order Chlamydiales, with emphasis on new species of Chlamydophila abortus, the causal agent of chlamydial abortion. This study reviews the recent experimental data which indicate the sites of entry of the organism, the way of its dissemination and establishment to the placenta. It also reviews current research on the humoral and cell-mediated immune responses, the role of the IFN-γ in latent infection and this of Tcells in the protective immune response. Finally, particular reference is given on the role of the male in the disease transmission and the role of inter-species contamination in chlamydial abortion.