Abortion In Cattle Research Articles

Natural superfetation idiopathic abortion in Pasundan cattle

Abortion in cows is a condition in which the foetus is unable to survive until it is born. This paper is the first report of a case of superfetated idiopathic abortion from natural mating that occurred in primiparous Pasundan cows. The cows were initially kept in a colony pen system and mixed between young bulls (n=10) and heifers (n = 18) for two weeks after moving the cows from the livestock pen in Ciamis Regency. Pregnancy occurs because of natural mating in heifers without a known age and pregnancy history. Two months later, a primiparous Pasundan cow was observed to show symptoms of vaginal bleeding and straining, accompanied by the expulsion of a small foetus (length ~ 25 cm, foetal age ~ 120 days) several hours later and had previously experienced an abortion with a large foetus (length ~ 36 cm, foetal age ~150 days). Primiparous Pasundan cows that experienced abortion were separated into individual pens to reduce stress and for further observation. The therapy given is antibiotics and multivitamins were administered as therapeutic agents.

A Current Update on Neospora caninum

Neospora caninum is an apicomplexan protozoan parasite, which was first identified as a cause of canine paralysis. This parasite is now recognized as an important cause of reproductive problems and abortion in cows. Prior to its first recognition in Norwegian dogs in 1984 and consequential classification as a distinct species in 1988, many N. caninum infections were misdiagnosed as toxoplasmosis. Neospora has a complex life cycle and transmission routes. Carnivores probably become infected by ingesting tissue cysts containing bradyzoites, and herbivores probably become infected by the ingestion of food or drinking water contaminated by N. caninum sporulated oocysts from the feces of carnivores. During pregnancy it becomes activated again, breaks out of the tissue cysts and migrates to the placenta. Infection of the placenta may lead to abortion, which would provide a source of contaminated meat for definitive hosts. In addition, the parasite may be transmitted to the foetus, which can lead to the birth of congenitally and persistently infected calves. Most reports of neosporosis outbreaks have occurred in cows that are intensively managed; thus, the incidence increases as larger cattle farms with intensive feeding practices become more common. Immunofluorescent antibody test (IFAT) and indirect enzyme-linked immunosorbent assay (ELISA) and histopathology of fetus are used for diagnosis. At present, there is no effective treatment for bovine neosporosis. Control of abortion in infected cattle depends on saving food and water sources and the grazing environment from feces of carnivores, properly discarding aborted feoutus and control of dog.

The devastation of Lumpy skin disease in third world countries: a mini – review on the current status of the disease focusing phytochemicals

Lumpy skin disease is a rising bovine viral illness that is widespread in most African and Middle Eastern nations, with a high probability of disease transmission throughout the Asia and Europe. The causative agent is capripoxivirus endangering hundreds of dairy cattle across the country in recent years. The LSD virus infects cattle and buffaloes and results in nodular skin sores all over their bodies. This results in chronic debility, decreased milk supply, poor development, infertility, abortion, and other issues in cattle and buffaloes infrequently leading to death of animals. The only infected animal species are cattle and water buffalo, both of which have high morbidity and low mortality rates. However, mortality rates are greater in calf populations. LSD causes sterility in males and abortions in female cattle. This mini review highlights existing information on epidemiology, pathogenesis, clinical manifestations, and potential role of phytochemicals particularly turmeric and aloe vera in treating lumpy skin disease.

Comprehensive diagnosis of abortion in cattle

Abstract. Abortion is one of the most common factors that has an extremely negative eff ect on the reproductive capacity of cattle, resulting in signifi cant economic losses. Abortions can be caused by infectious and non-infectious agents. Diagnosis of abortion is a diffi cult task, since only about 40% of abortions are diagnosed as infectious, and the remaining 60% - as unknown etiology. The goal was to establish the infectious etiology of abortion using complex diagnostics. The research was carried out in the laboratories of "Center of Veterinary Diagnostics" LLC (Kyiv). The selection of samples for research was carried out in the section hall of the LLC "Center of Veterinary Diagnostics" during the autopsy. The material for the study was a fetus and a vaginal smear from an aborted cow. Abortion occurred at 4 months of pregnancy. To establish the etiology, the following research methods were used: patho-anatomical, bacteriological, histological and molecular genetic (PCR-RT). Autolysis, light gray foci ≤ 2 mm in diameter in the lungs, and multiple light gray foci ≤ 1 mm in diameter in the liver were the main pathological fi ndings. The main pathohistological changes detected were focal myocarditis, intranuclear inclusion bodies in hepatocytes, multifocal coagulation necrosis in the lungs and liver, and diff use interstitial nephritis. Bacteriological culture was negative. DNA of infectious bovine rhinotracheitis virus (IBRV) and DNA of bovine herpesvirus type 4 (BHV-4) was isolated from the examined samples of fetal tissues and vaginal smear by PCR-RT. Using a comprehensive study, infectious agents and changes characteristic of the infectious process were identifi ed. On the basis of the obtained results, the etiology of the abortion was established as co-infection of IBRV and BHV-4. Complex diagnostics provides an opportunity to establish a cause-and-eff ect relationship between the identifi ed infectious agent and pathological changes in the fetus and the etiology of abortion. The results of a set of studies provide information on the manifestation of herpesvirus co-infection and complement the existing knowledge that can be used in the diagnosis of abortions in cows. Key words: abortion, cattle, IBRV, BHV-4, coinfection, PCR-RT, pathohistology, diagnosis.

Transcriptome profiling of Madin-Darby bovine kidney cells uncover differences in the susceptibility of cattle to Toxoplasma gondii and Neospora caninum

Toxoplasma gondii and Neospora caninum are two major apicomplexan protozoan parasites with heteroxenous life cycles and worldwide distributions. The transplacental transmission of N. caninum causes bovine abortion, which resulting in serious economic losses to the dairy industry. Although T. gondii was also reported to cause abortions in pregnant woman and small ruminants, scarce cases about the symptom to the host cattle and the causality remains unknown. In this study, transcriptome analysis of Madin Darby bovine kidney (MDBK) cells infected with T. gondii and N. caninum was performed to uncover the differences in susceptibility of cattle to the two parasites. The results showed that 256 and 2225 differentially expressed genes (DEGs) were detected in cells infected with N. caninum and T. gondii, respectively. Moreover, significant biological differences were revealed by the functional analysis including GO and KEGG enrichment. One serpin peptidase inhibitor (SEPRINA14), which is associated with immunosuppression during pregnancy, was found to significantly decrease in cells infected with N. caninum and increase in cells infected with T. gondii-infected cells. Pattern recognition receptors TLR3 and NOD2 were also significantly upregulated in N. caninum-infected MDBK cells, but not in T. gondii. They could induce an increased inflammatory response leading to severe tissue damage. In addition, the interleukin 12 receptor subunit beta 2 (IL12β2), which plays an essential role in Th1 and Th2 cell differentiation and inflammatory bowel disease, was also markedly upregulated in the N. caninum infected cells, which led to an imbalance in the Th1 and Th2 cells by promoting the Th1 cellular response. Altogether, our findings recognized a new understanding on the differences between T. gondii and N. caninum infection of MDBK cells, where SEPRINA14, TLR3, NOD2, and IL12β2 may be the key genes that affect the difference in susceptibility of cattle to T. gondii and N. caninum, especially in pregnant animals. This study provides more clues as to why N. caninum is more likely to cause abortions in cattle.

Uncommon bovine viral diarrhea virus subtype 1e associated with abortions in cattle in southern Brazil.

We characterized bovine viral diarrhea virus (BVDV)-related abortions in cattle and identified the species and subgenotypes in the state of Santa Catarina, southern Brazil. Our RT-PCR assay was positive for BVDV in 5 fetuses from different farms; however, 3 of the 5 fetuses were also PCR-positive for Neospora caninum. In the 5 BVDV-positive fetuses, gross lesions included fetal mummification (1), hepatomegaly (1), subcutaneous edema (1), and perirenal edema (1). Predominant histologic lesions included epicarditis and mild-to-moderate lymphoplasmacytic myocarditis (5), mild multifocal lymphoplasmacytic interlobular pneumonia (4), nephrosis associated with moderate multifocal interstitial nephritis (1), moderate multifocal lymphoplasmacytic necrotic hepatitis (1), and mild multifocal lymphoplasmacytic meningitis (1). The amplification products from the Pestivirus 5'UTR region of 4 of the 5 fetuses had 96.3-100% similarity between fetal strains and reference strains. The samples were distributed into 2 branches of the phylogenetic tree; strains UDESC:01, UDESC:02, and UDESC:05 clustered in the BVDV-1e branch, uncommon in the Americas, and strain UDESC:04 clustered in the BVDV-2b branch. The three 1e strains had 96.9-97.4% similarity.

Dysfunction, oxidative stress markers, and cytokine expression in the placentae of mice experimentally infected with Neospora caninum.

Neosporosis is the major cause of abortion and reproductive failures in cattle, leading to significant economic losses. In this study, we evaluated the impact of Neospora caninum infection on oxidative stress (OS) markers and local cytokine mRNA expression at the placenta, as well as its effect on the progesterone (P4) serum levels and systemic cytokine profile in a pregnant mouse model. Infected pregnant mice (NC-1 group) showed increased percentages of fetal losses and IFN-γ serum levels, decreased serum progesterone, increased placental mRNA expression levels of both Th1-type (IFN-γ and TNF-α) and Th2-type (IL-4) cytokines, and inhibited expression of TGF-β1 (Treg) compare to control dams (CONTROL group). In addition, lipid peroxidation and ROS were increased, whereas the antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT) activities were modified in the placentae of infected mice compared to control mice. These findings demonstrate that multiple factors, including placental OS, are involved in fetal losses associated with N. caninum infection in mice, thus OS contribution to the placental physiopathology of neosporosis in other hosts must not be ruled out.

Türkiye’de kızıl tilki beyin (Vulpes vulpes) örneğinde Neospora caninum’un ilk moleküler tespiti

The red fox is the wild carnivore with the widest distribution in the world. Thus, this animal acts as intermediate and final host for many parasite species. Neospora caninum is one of the most important protozoan agents causing abortion in cattle, sheep and goats in the world. The final hosts of N. caninum are domestic dogs and wild canids such as wolves and coyotes, while its intermediate hosts are domestic ruminants and many warm-blooded animals, including red foxes. The aim of this study was to research N. caninum in brain samples of three red foxes obtained from wildlife in Türkiye by using PCR. At the end of the study N. caninum DNA was detected in one of three brain samples. To the best of our knowledge, with this study, N. caninum was detected for the first time in a red fox brain sample in Türkiye.

Neospora caninum infection in dairy cattle in Egypt: a serosurvey and associated risk factors

Neospora caninum (N. caninum) is one of the causative agents that causing cattle abortion, and severe economic losses. Due to the scarcity of data on N. caninum infection in Egyptian cattle, the purpose of this study was to estimate the seroprevalence and determine the risk factors for parasite infection. In four governorates in northern Egypt, 540 blood samples from cattle were taken, and tested using a commercial ELISA kit. The overall seroprevalence of N. caninum in examined cattle was 28.89%. A multivariate logistic regression model determined that age (OR = 2.63, P < 0.001), manual milking (OR = 1.39, P = 0.14), abortion history (OR = 2.78, P < 0.0001), repetition of estrus (OR = 2.31, P < 0.0001), and contact with dogs (OR = 2.57, P < 0.0001) were significant risk factors. The findings proved that N. caninum infection was one of the factors contributing to abortion and financial losses in dairy cattle in Egypt. Therefore, the application of sanitary security and control programs is very important in dairy farms.

Investigation of virulence factors, phylogenetic grouping, multiple-locus variable number tandem repeat analysis, and antimicrobial susceptibility of E. coli isolated from aborted bovine fetal tissue.

Escherichia coli is an important microorganism for cattle breeding. The aim of this study was to investigate the presence of phylogenetic groups, virulence factors, genotyping with multi-locus variable tandem repeat analysis (MLVA), and susceptibility to commonly used antimicrobial agents in E. coli strains isolated from aborted bovine fetal samples. In this study, phylogrouping and various virulence genes were analyzed by PCR in E. coli strains isolated from 637 bovine fetal tissue samples. Consequently, E. coli was isolated and identified in 24 samples in culture. Of the 24 isolates identified as positive, 12.5% were defined as group A, 83.3% as B1, and 4.2% as group B2. Of the E. coli isolates, virulence factor fimH was identified in eight (33.3%), traT in 15 (62.5%), ompT in five (20.8%), CNF1 in one (4.16%), and CNF2 in six (25%). Seven genotypic groups were determined as a result of the analysis with the MLVA 10 method. According to the antimicrobial susceptibility test results, high resistance was determined against amoxicillin/clavulanic acid and oxytetracycline. In conclusion, strains of E. coli containing CNF1, CNF2, fimH, traT, and ompT virulence factors can be associated with bovine abortions. It is noteworthy that the dominant phylogenetic group B1 has been observed in cases of cattle abortions.

Seroprevalence of Chlamydia abortus in Anestrous Cattle of Nawalpur and Chitwan District, Nepal

Chlamydia abortus are gram negative coccoid, obligate intracellular zoonotic bacteria responsible for abortion and other reproductive problems in dairy cattle. This leads to sub-fertility and infertility in cattle thereby causing significant economic losses to dairy farmers. However, the status of Chlamydia abortus in Nawalpur and Chitwan districts, which are the dairy pockets of Nepal, are poorly understood. The objective of this study was to determine the seroprevalence of antibodies to Chlamydia abortus in anestrous dairy cattle of Nawalpur and Chitwan districts in relatively low risk winter season. In total, 92 cattle serum (Nawalpur (n= 27) and Chitwan (n= 65) samples were collected from April 2018 to May 2019 and tested using a Chlamydia abortus specific indirect ELISA kit to evaluate the seropositivity status of cattle. Results showed that only 2 (2.17%) cattle were seropositive for Chlamydia abortus. Both the positive cattle were Jerseys from Nawalpur area with a history of abortion. The ages of the seropositive cattle were 3 and 4 years. In conclusion, there was a low seroprevalence of C. abortus in dairy cattle of Nawalpur and Chitwan districts. The presence of this bacterium suggests that it is likely to be a cause of unidentified abortion in dairy cattle in Nepal. We suggest screening dairy animals for C. abortus infection to minimize this risk.

Recombinant Dense Granule Protein (NcGRA4) Is a Novel Serological Marker for Neospora caninum Infection in Goats.

Neospora caninum is widely recognised as one of the most significant causes of abortion in cattle, with infections also occurring in sheep and goats. To prevent and control animal neosporosis, it is crucial to develop sensitive and specific methods for detecting N. caninum infection. Recently, several recombinant proteins have been utilised in serological assays for the diagnosis of neosporosis. In this study, we used commercial gene synthesis to produce dense granular antigen 4 (NcGRA4) recombinant protein. NcGRA4 plasmids were expressed in the Escherichia coli system and then purified. The purified recombinant protein was analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis. To evaluate the diagnostic potential of recombinant NcGRA4 protein, we tested 214 serum samples from goat farms via indirect enzyme-linked immunosorbent assay (iELISA) and compared the results to those from the indirect fluorescent antibody test (IFAT). Western blotting analysis revealed a single NcGRA4 band with an expected molecular weight of 32 kDa. The specific IgG against N. caninum was detected in 34.1% and 35% of samples evaluated by NcGRA4 iELISA and IFAT, respectively. The sensitivity and specificity of the NcGRA4 iELISA were 71.6% and 86.3%, respectively, when compared with the results from IFAT. Our results demonstrate that a recombinant protein that can be used to detect animal neosporosis can be produced using a synthetic NcGRA4 gene. Overall, recombinant NcGRA4 shows promise as a sensitive and specific serological marker for identifying target IgG in goat samples.

Brucellosis : Review on Routine and Molecular Technique for Diagnosis of Neglected Disease

Brucellosis is a zoonotic infection transmitted from animals to humans through the consumption of contaminated food, direct contact with an infected animal, or inhalation of aerosols. The latter method is extremely effective given the relatively low concentration of organisms required to induce infection in humans and has put this centuries-old disease back in the spotlight. Brucella is a facultative intracellular pathogen that has the ability to survive and multiply in phagocytes and cause abortion in cattle and ripple fever in humans. Brucella spp., especially B. Abortus, B. melitensis, and B. suis pose a serious public health problem. B. melitensis is the most common cause of human brucellosis in India. Human brucellosis still poses several challenges for clinicians and scientists, including understanding the pathogenic mechanism, severity, and progression, and developing improved therapeutic regimens. Molecular studies have shed light on the pathogenesis of Brucella to develop new diagnostic tools that will be useful in developing countries where brucellosis is a common but often overlooked disease. This overview brings together all these questions, especially pathogenicity and new diagnostic tools.

Neglected zoonotic bacteria causes and associated risk factors of cattle abortion in different agro-ecological zones of southwest Ethiopia

Three zoonotic bacteria, Coxiella burnetii, Leptospira spp, and Brucella spp, cause cattle abortion and significant losses in the livestock sector. However, these infections were neglected diseases in Ethiopia. Between October 2020 and October 2021, a cross-sectional study was carried out in southwest Ethiopia to determine the prevalence of abortion and identify the major zoonotic bacterial causes and risk factors that contribute to abortion. Using an indirect ELISA, antibodies to Brucella abortus, Leptospira Hardjo, and Coxiella burnetii were detected in serum samples taken from 461 cattle. Potential risk factors for cattle abortion were found using a multivariable random effect logistic regression analysis. The prevalence of cattle abortion was found to be 22.56 % (95 % CI: 18.74–26.38) in the study areas. Leptospira Hardjo (OR=1.8, 95% CI: 1.04–3.00), Coxiella burnetii (OR=2.7, 95 % CI: 1.26–5.62), and Brucella abortus (OR=9.8, 95 % CI: 1.27–17.15) were all associated with the occurrence of abortion in cattle, as were their co-infections (OR=8.1, 95 % CI: 1.28–39.33). Other risk factors for cattle abortion included breed (OR=16.7, 95 % CI: 2.20–26.77), herd size (OR=2.5, 95 % CI: 1.16–4.68), breeding method (OR=2.3, 95 % CI: 1.33–3.90), and contact with dogs (OR=2.2, 95 % CI: 1.34–3.53). According to the findings of this study, Brucella abortus, Coxiella burnetii, and Leptospira Hardjo are serious zoonoses that cause significant production loss in cattle due to abortion. To prevent transmission of these zoonotic diseases, it is crucial to implement effective control measures and increase public awareness. The causes of cattle abortion in the study areas should also be isolated and characterized.

Why be interested in Neospora caninum on farm?

Infection of cattle with Neospora can cause abortion, making this pathogen the most commonly diagnosed pathogen in cattle abortion investigations in the UK. However, the parasite can also cause latent infections in otherwise clinically unaffected cattle following both horizontal and vertical transmission. Monitoring and surveillance is justified in beef and dairy herds, and an understanding of the pathogenesis is required to work with owners to manage and control the effects within a herd. This article explores all these aspects and uses a case study to discuss a presentation with a significant herd impact, and associated approach to diagnosis and control plan.

Congenital transmission of Neospora caninum in wild ungulates and foxes.

Neospora caninum is one of the main causes of abortion in cattle. In wildlife, the occurrence and relevance of vertical infection have not been yet clearly evaluated. The aim of this study was to verify the possibility of vertical transmission of N. caninum in three wild species extensively distributed in Europe, namely roe deer Capreolus capreolus, wild boar Sus scrofa and red fox Vulpes vulpes. A total of 190 fetuses (72 wild boars, 67 foxes and 51 roe deer) from 61 females were included in the study. All animals, which were either found dead or culled within selective control plans in North-western Italy, were tested, in parallel by PCR on central nervous system, skeletal muscle and kidney. The efficiency of vertical transmission in the three target species was of 87.5% (95% CI 69.00-95.66).

Temporal transcriptomic changes in microRNAs involved in the host immune response and metabolism during Neospora caninum infection

BackgroundNeospora caninum infection is a major cause of abortion in cattle, which results in serious economic losses to the cattle industry. However, there are no effective drugs or vaccines for the control of N. caninum infections. There is increasing evidence that microRNAs (miRNAs) are involved in many physiological and pathological processes, and dysregulated expression of host miRNAs and the biological implications of this have been reported for infections by various protozoan parasites. However, to our knowledge, there is presently no published information on host miRNA expression during N. caninum infection.MethodsThe expression profiles of miRNAs were investigated by RNA sequencing (RNA-seq) in caprine endometrial epithelial cells (EECs) infected with N. caninum at 24 h post infection (pi) and 48 hpi, and the functions of differentially expressed (DE) miRNAs were predicted by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The transcriptome data were validated by using quantitative real-time polymerase chain reaction. One of the upregulated DEmiRNAs, namely chi-miR-146a, was selected to study the effect of DEmiRNAs on the propagation of N. caninum tachyzoites in caprine EECs.ResultsRNA-seq showed 18 (17 up- and one downregulated) and 79 (54 up- and 25 downregulated) DEmiRNAs at 24 hpi and 48 hpi, respectively. Quantitative real-time polymerase chain reaction analysis of 13 randomly selected DEmiRNAs (10 up- and three downregulated miRNAs) confirmed the validity of the RNA-seq data. A total of 7835 messenger RNAs were predicted to be potential targets for 66 DEmiRNAs, and GO and KEGG enrichment analysis of these predicted targets revealed that DEmiRNAs altered by N. caninum infection may be involved in host immune responses (e.g. Fc gamma R-mediated phagocytosis, Toll-like receptor signaling pathway, tumor necrosis factor signaling pathway, transforming growth factor-β signaling pathway, mitogen-activated protein kinase signaling pathway) and metabolic pathways (e.g. lysine degradation, insulin signaling pathway, AMP-activated protein kinase signaling pathway, Rap1 signaling pathway, calcium signaling pathway). Upregulated chi-miR-146a was found to promote N. caninum propagation in caprine EECs.ConclusionsThis is, to our knowledge, the first report on the expression profiles of host miRNAs during infection with N. caninum, and shows that chi-miR-146a may promote N. caninum propagation in host cells. The novel findings of the present study should help to elucidate the interactions between host cells and N. caninum.Graphical

Wild animal densities as predictors of cattle disease risks and breed types in southwestern Uganda.

This study investigated the spatial distribution of wild ungulates that pastoralist communities perceive as culprits in the transmission of cattle diseases outside protected areas in southwestern Uganda.Diseases are hypothesized as having influence on pastoralists' choice of cattle breed types. Until now, there have been no studies conducted on spatial patterns of wild animal species association with cattle breeds reared in Lake Mburo Conservation Area (LMCA), and how diseases transmitted therein potentially influence cattle breed herd sizes. Animal population survey was carried out on cattle and wild ungulate species along transect lines laid perpendicular to the northern boundary of Lake Mburo National Park (LMNP). Data on the costs of cattle mortality and disease control were gathered using face-to-face interviews. We used SPSS version 17 for descriptive statistics to summarize unit cost of disease control at herd level, whereas chi-square (χ2) tests of goodness-of-fit were used to analyze observations on frequency of wild animal sightings, whose association with spatial distribution patterns of cattle breeds was examined using Pearson correlation test. Our results show inverse association of distance away from LMNP with wild animal populations and the cost of cattle disease control. The mean population of exotic cattle significantly increased as that of indigenous cattle decreased with increasing distance from LMNP. In a similar way, the cost of disease control and cattle abortion incidences were much lower in rangelands far away from LMNP (R2 = 0.965,p < 0.001). Spatial distribution of wild ungulates was significantly associated with reported cattle mortality, disease, and cost of disease control. Diseases and their costs of control potentially influenced spatial patterns of cattle breeds and breed herd sizes in LMCA, which in turn could affect range resource use for conserving different species of wild animals outside protected area.

Genomic epidemiology of Campylobacter fetus subsp. venerealis from Germany.

Campylobacter fetus subsp. venerealis (Cfv) causes bovine genital campylobacteriosis (BGC), a World Organization for Animal Health (WOAH)-listed trade-relevant disease characterized by severe reproductive losses, such as infertility, early embryonic death and abortion in cattle. BGC has significant economic implications that have prompted several countries to adopt stringent eradication and surveillance measures to contain the disease. In Germany, there has been a low incidence of BGC cases over the past 28 years. This study aimed to illustrate the genomic diversity of German Cfv strains isolated from different federal states in Germany. This study analyzed 63 Cfv strains, collected between 1985 and 2015, by whole-genome sequencing and compared them with genome data of 91 international Cfv isolates. The phylogenetic analysis showed that the Cfv population is genetically conserved and has geographic clusters. In Germany, one phylogenetic lineage comprising all strains was identified. This German lineage was part of a subclade that probably emerged in the nineteenth century and diversified over time. The results of this study point to a non-recurrent cross-border introduction of Cfv in Germany. The BGC control interventions in Germany can be considered successful as no outbreaks were reported since 2015.

Immunization with a Multivalent Listeria monocytogenes Vaccine Leads to a Strong Reduction in Vertical Transmission and Cerebral Parasite Burden in Pregnant and Non-Pregnant Mice Infected with Neospora caninum.

Neospora caninum is an apicomplexan parasite that causes abortion and stillbirth in cattle. We employed the pregnant neosporosis mouse model to investigate the efficacy of a modified version of the attenuated Listeria monocytogenes vaccine vector Lm3Dx_NcSAG1, which expresses the major N. caninum surface antigen SAG1. Multivalent vaccines were generated by the insertion of gra7 and/or rop2 genes into Lm3Dx_NcSAG1, resulting in the double mutants, Lm3Dx_NcSAG1_NcGRA7 and Lm3Dx_NcSAG1_NcROP2, and the triple mutant, Lm3Dx_NcSAG1_NcGRA7_NcROP2. Six experimental groups of female BALB/c mice were inoculated intramuscularly three times at two-week intervals with 1 × 107 CFU of the respective vaccine strains. Seven days post-mating, mice were challenged by the subcutaneous injection of 1 × 105N. caninum NcSpain-7 tachyzoites. Non-pregnant mice, dams and their offspring were observed daily until day 25 post-partum. Immunization with Lm3Dx_NcSAG1 and Lm3Dx_NcSAG1_NcGRA7_NcROP2 resulted in 70% postnatal pup survival, whereas only 50% and 58% of pups survived in the double mutant-vaccinated groups. Almost all pups had died at the end of the experiment in the infection control. The triple mutant was the most promising vaccine candidate, providing the highest rate of protection against vertical transmission (65%) and CNS infection. Overall, integrating multiple antigens into Lm3Dx_SAG1 resulted in lower vertical transmission and enhanced protection against cerebral infection in dams and in non-pregnant mice.