Agent Of Abortion Research Articles

Protecting babies: vaccine strategies to prevent foetopathy inNeospora caninum‐infected cattle

Neospora caninum is an apicomplexan protozoan parasite that is a significant infectious abortifacient agent in cattle. Despite the fact that it is a member of a well described taxonomic group, it is a relatively newly discovered parasite and its biology is not yet fully understood. Cattle become infected either congenitally via transplacental transmission or post-natally by ingesting oocysts derived from the definitive host; dogs and coyotes are the only definitive hosts that have been described to date. It is not known which of these two forms of transmission occurs most frequently and which is the most likely to result in abortion; there are no drugs available to treat infected cattle, so current control strategies rely on prevention of infection by management methods and strict hygiene; an effective vaccine would be a great advantage in its control. Neospora caninum is an economically important veterinary pathogen, but we can also draw analogies between its foetopathic effects and those of human pathogens such as Toxoplasma gondii, Chlamydophila abortus and Plasmodium falciparum. Understanding the immune response and the materno-foetal relationship in N. caninum-infected cattle may help us to design vaccination strategies, not only for neosporosis but also for other foetopathic agents.

Development and production of vaccines against abortion caused by Chlamydophila abortus and Coxiella burnetii in small ruminants

Chlamydophila abortus and Coxiella burnetii are obligate intracellular parasites, small Gram-negative bacteria, which are aetiological agents of abortion in small ruminants. The organisms also have zoonotic potential, which highlights the importance of the prevention of the transmission of these diseases. Treatment of infected animals with oxytetracycline and its derivatives, can limit abortions, but does not suppress the bacterial excretion, therefore the only effective solution against the infection is the prevention by vaccination. To produce and make available such vaccines, is a long process from the emergence of a concept, through feasibility, development, production, control until obtaining marketing authorisation, and it can take 5–10 years or more. After registration, pharmacovigilance follows the vaccines on the field. C. burnetii and Cp. abortus present serious health risk to humans (Class II and III micro-organisms), thus the propagation of living bacteria is performed in confined Class III areas. Our vaccine strain against chlamydiosis is Cp. abortus 1B ts, whilst the strain of vaccine developed against coxiellosis is C. burnetii Nine Mile phase I. We present hereby the advantages of these vaccines produced with the strains mentioned above over other, existing vaccines and describe their major phases of production.

The Corticotropin-Releasing Factor (CRF) Family of Neuropeptides in Inflammation: Potential Therapeutic Applications

Hypothalamic CRF plays a central role in the coordination of endocrine and behavioral responses to stress and it is also involved in the pathophysiology of several neuropsychiatric diseases including depression, anxiety and addiction. In the mammals, the CRF family of peptides includes CRF, urocortin (Ucn), Ucn I, and Ucn II while was enriched with new members, the urocortins. Their biological effects are mediated by the CRF1 and CRF2 receptors, which belong to the G-protein-coupled receptor super family. Multiple research groups have demonstrated during the last decade the expression of the CRF peptides and their receptors in several components of the immune system and their participation in the ad hoc regulation of inflammatory phenomena. Non-peptide CRF1 antagonists have been recently synthesized for the treatment of CNS related diseases, such as anxiety, depression and drug abuse. In the gastrointestinal tract, these compounds open new therapeutic options in the treatment of lower-GI inflammatory diseases associated to CRF, such as the chronic inflammatory bowel syndromes, irritable bowel disease and ulcerative colitis while Ucn, Ucn I, Ucn II or synthetic non-peptide CRF2 agonists may be useful in the treatment of upper-GI inflammatory diseases. In human endometrium, CRF1 antagonists may be used as abortive agents interfering with the inflammatory phenomena taking place during the implantation of the conceptus. They thus may represent a new class of nonsteroidal inhibitors of implantation. These two examples illustrate the potential therapeutic significance of the CRH in regulating inflammatory phenomena in an ad hoc approach without affecting the rest of the immune system.

Hematosalpinx: an unusual complication after medical abortion with oral mifepristone and misoprostol

We report a case of unilateral hematosalpinx after medical abortion with oral mifepristone/misoprostol, a technique being increasingly used in current obstetric practice in Taiwan. A 36 year-old pregnant woman, gravida 3 para 2, attended for medical abortion counseling at 6 weeks' gestation. She had previously undergone laparoscopic enucleation of a left ovarian endometrioma and pelvic adhesiolysis, and had subsequently had two Cesarean sections for obstetric indications. Transvaginal ultrasonographic examination showed a viable intrauterine embryo of compatible gestational age and unremarkable bilateral adnexa. After thorough counseling, the couple elected to undergo medical abortion with oral mifepristone (600 mg) followed 48 hours later by 400 µg of oral misoprostol. She returned 1 week later for a follow-up ultrasound scan and complained of abdominal cramping. On ultrasound examination the intrauterine gestational tissue had been expelled completely but a large (7 cm) heterogeneous echogenic left adnexal mass (Figure 1), thought to be a hematosalpinx, was noted. Color Doppler flow mapping showed no intratumoral blood flow with peripheral low-velocity and high-resistance flow signals (resistance index (RI) = 0.78). Her serum CA125 level was elevated, at 887 U/mL. The left hematosalpinx resolved completely 4 months later. At the time of writing she has been followed up for over a year and has had an uneventful clinical course. Follow-up ultrasonographic examination 1 week after medical abortion showed a heterogeneous echogenic left adnexal mass (M). Mifepristone (RU-486), an antiprogestin, has more than double the binding affinity for progesterone receptor as does progesterone itself1. The actions of mifepristone on the reproductive system make it a useful agent for abortion. Misoprostol, an orally active and inexpensive prostaglandin E1 analog, increases uterine activity especially when used in conjunction with mifepristone. Current evidence suggests that either 200 mg or 600 mg mifepristone followed 36 to 48 hours later with 400 µg of oral misoprostol or 800 µg of vaginal misoprostol are effective for abortion at up to 49 days' gestation. Mifepristone affects not only a woman's reproductive system, but her cardiovascular, digestive and central nervous systems as well2. Patients who opt to have medical abortion should be counseled about the side effects of this combination regimen. The best known adverse effects are cramping and nausea, but other side effects such as vomiting, diarrhea, headache, dizziness and fever or chill occur in up to 15% of patients3. Two-thirds of the patients with cramp may need pain medication, but opiates are required in less than 2%. Most women will bleed for 13–15 days, and a few (less than 10%) will bleed for over 30 days4. The incidental findings of a huge adnexal mass with abnormally high serum CA125 levels in our case after medical abortion with oral mifepristone and misoprostol are unusual. The diagnosis was made by comparing pre- and postabortion ultrasonographic findings (indicating an acute lesion) and the appearance of the lesion with its elongated shape and fibrin-like contents. Pregnant women and gynecologists who decide to terminate an unwanted pregnancy with this technique need to familiarize themselves with its efficacy and complications. Acute hematosalpinx appears to be a rare complication, but one which should be borne in mind if there is lower abdominal pain after medical termination of pregnancy. S. K. Lin*, E. S. C. Ho*, Y. J. Chen*, * Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, 160, Section 3, Taichung-Kang Road, Taichung 407, Taiwan, R.O.C.

Diagnosis of ovine chlamydial abortions by PCR-RFLP performed on vaginal swabs

Ovine enzootic abortion is an infectious and contagious disease clinically characterized by abortion and weak neonates, affecting sheep and goats. The etiological agent is Chlamydophila (C.) abortus, which is considered one of the most common animal pathogens of small ruminants; it has important economic implications and represents a significant zoonotic risk. Clinical diagnosis is often difficult because the clinical signs and the pathological lesions are not specific for C. abortus infection, in fact they can also be observed as a result of infections with other abortifacient agents. Moreover, the involvement of the laboratory is necessary to perform the definitive diagnosis. One hundred and seventeen vaginal swabs from sheep with clinical signs related to chlamydial infection were examined by a PCR-RFLP assay that demonstrated high specifity and sensitivity. Six samples were positive for C. abortus. Vaginal swabs are easy to handle and allow to deal with biohazardous material in safety conditions.

Influence of the Th2 immune response established by Nippostrongylus brasiliensis infection on the protection offered by different vaccines against Chlamydophila abortus infection

Chlamydophila abortus is the aetiological agent of enzootic abortion in small ruminants in which it infects the placenta to cause abortion during the last trimester of gestation. In a mouse model, a Th1 immune response involving IFN-gamma production and CD8+ T cells is necessary for the infection to be resolved. The authors previously demonstrated that infection with Nippostrongylus brasiliensis, a rodent gastrointestinal nematode extensively used in experimental models to induce Th2 responses, alters the specific immune response against C. abortus infection, increasing bacterial multiplication in liver and reducing specific IFN-gamma production. The aim of the present work was to clarify whether a Th2 immune response has any influence on the success of vaccination using both inactivated and attenuated vaccines. The results showed that the Th2 response established prior to vaccination did not influence the induction of protection offered by the vaccines. However, the effectiveness of this protective response can be altered, depending on the adjuvant employed in the inactivated vaccines, when the Th2 response is established after vaccination, just before challenge with C. abortus.

Molecular Identification of a Novel Deltaproteobacterium as the Etiologic Agent of Epizootic Bovine Abortion (Foothill Abortion)

Epizootic bovine abortion (EBA) is endemic in California's coastal range and the foothill regions of the Sierra Nevada, where it has been the primary diagnosed cause of abortion in beef cattle for >50 years. Investigation of these losses has defined a specific fetal syndrome characterized by late-term abortion or birth of weak or dead calves. Although the unusual clinical presentation and unique fetal pathology associated with EBA have been recognized since the 1950s, the identity of the etiologic agent is unknown. In this study, suppression-hybridization PCR was used to identify a fragment of the 16S rRNA gene of a previously undescribed bacterium in thymus tissue derived from affected fetuses. Phylogenetic analysis revealed that this pathogen was a deltaproteobacterium closely related to members of the order Myxococcales. A specific PCR was subsequently developed to detect the presence of this bacterium in DNA extracted from fetal thymuses. Using histopathology as the definitive diagnosis for EBA, this PCR demonstrated 100% specificity and 88% sensitivity. The bacterium was also detected in the argasid tick Ornithodoros coriaceus, which is the recognized vector of EBA. These data imply a close association between this novel agent and the etiology of EBA.

CLUSTER

The two most effective cluster abortive agents are injectable sumatriptan and inhaled oxygen. Because most cluster headache sufferers are cigarette smokers and at high risk of coronary artery disease, many develop contraindications to triptans. Oxygen, the safest of all cluster therapies, is not effective for every patient. In Kudrow's landmark study, 75% of patients responded to 100% oxygen at 7 L/min, although only 57% of older chronic cluster headache patients had relief. A recent study documented a gender difference in response to oxygen because only 59% of female cluster patients responded to oxygen, whereas 87% of men did. In most textbooks and articles on cluster headache treatment, patients are instructed to use 100% oxygen via a nonrebreather face mask at 7 to 10 L/min. The rationale behind this prescribed oxygen‐flow rate is unknown but has become doctrine since the Kudrow study. Prescribing higher flow rates of oxygen up to 12 L/min has recently been suggested, but there is no documentation that this may improve efficacy. Higher oxygen‐flow rates (up to 15 L/min) are not known to benefit cluster headache patients refractory to standard oxygen therapy. Three cluster headache patients who demonstrated no response to standard oxygen therapy were exposed to higher flow rates of oxygen (14 to 15 L/min) to assess response. Comments: Once again, Dr. Todd Rozen's observations will change my clinical practice!—Stewart J. Tepper, MD I have questions: Were these empirical observations or do Drs. Kudrow and Rozen know how rate of flow affects oxygen delivery? Is oxygen uptake higher with higher flows? After all, 100% oxygen is 100% oxygen unless under hyperbaric pressure! Perhaps higher flow rates dry the nasopharyx to a greater extent. If patients perceive a higher flow rate, might this be an enhanced placebo effect? It seems like an interesting study to be conducted, and it would be useful to test if using nasal cannulae is just as good. Pulse oximetry and arterialized capillary blood gases could be used to monitor oxygen saturation and CO2 retention/carboxyhaemoglobin levels in smokers.—David S. Millson, MD

Inhibitor of Human Plasma Kallikrein DX-88 for the Treatment of Acute Attack in a Family with Hereditary Angioedema.

Hereditary angioedema (HAE) is an autosomal dominant disorder that results in a deficiency of C1 esterase inhibitor (C1-INH), with a 1/10,000 to 1/50,000 prevalence worldwide (Nzeako 2001). Affected individuals manifest with recurrent attacks of intense, massive, localized non-pitting edema, without an allergic component, responding poorly to epinephrine and steroids. Prophylaxis include antifibrinolytic or androgens. A worrisome potentially fatal complication is laryngeal edema, which currently has no abortive therapy available.C1-INH is a serine protease inhibitor that also regulates kinin generation. Angioedema results from uncontrolled activation of the classical complement pathway generating vasoactive peptide or contact system activation release of bradykinin from high molecular weight kininogen. Knockout mouse data supports the role of bradykinin for the edema generation. However, other mediators may be involved. C1-INH gene disruption in mice showed increased vascular permability, which was reversed by intravenous C1-INH, bradykinin, and plasma kallikrein inhibitor (Hun 2002). Therefore, DX-88 (Dyax Corporation), a recombinant polypeptide inhibitor of plasma kallikrein, was used as an abortive agent for the treatment of acute attacks in HAE. We describe our institution's experience in treating an HAE family, affected father with his two affected daughters, with DX-88 in a jointly conducted adult and pediatric hematology clinical trial. EDEMA I is an ascending four dose placebo controlled study to assess the efficacy and tolerability of DX-88 for acute attacks of HAE. Patients presented for treatment within 4 hours of a moderately severe acute attack and were observed for 8 hours. All three presented with abdominal attacks. The first daughter, on Oxandrin prophylaxis, presented with cramping, gnawing abdominal pain, associated nausea and rash. Subjective resolution of nausea, cramping and rash occured within 1 hour of treatment. The abdominal distention had partial resolution with continuing response up to 8 hours.The second daughter had more severe recurrent symptoms associated with her menses. She used imported C1-INH concentrate for acute attacks. She presented with mid to upper abdominal cramping and nausea. She had no resolution of symptoms with treatment. Her abdominal attack of 10/10 pain increased with nausea. She subsequent developed erythema marginatum.. The study was stopped 4 hours post dose. She was admitted for narcotic pain medication for symptomatic relief. The father, on Oxandrin prophylaxis, presented with abdominal attack, left hand and scrotal edema, and extensive erythema marginatum; reticular rash over the neck, back, arms, and shoulder. The attacks improved within 1 hour of treatment with significant resolution within 2 hours. The rash and abdominal symptoms resolved completely. The left hand and scrotal edema had partial resolution typical of his disease course, with continuing response up to 8 hours.HAE families have debilitating acute attacks despite prophylaxis. Replacement therapy with C1-INH concentrate is not commercially available in the United States. We treated an HAE family with DX-88 for acute attacks. Two had responses and the non responder was a potential placebo. The treatment was well tolerated. Longer follow up for safety and efficacy with ideal drug dosing are needed. Trial results are currently being analyzed. DX-88 is a promising, non plasma based, treatment for acute attacks of patients with HAE.

Epidemiologic Approaches for Measuring and Understanding Abortion in Dairy Cows

This paper offers methods for measuring abortion risk and undertaking abortion diagnostic investigations. In addition, some of the associations found between demographic and reproductive features of the dam and subsequent abortion are described. The cohort life table method is used to compute risk of fetal loss (abortion) for pre-defined time intervals (eg. days or weeks) during the gestation period, as well as overall proportion of cows that abort. In contrast, the abortion density method calculates abortion risk for a defined calendar time (eg. per month) as the number of abortions per cowdays- at risk. Both methods are standardized to account for the changing number of cows at risk of abortion, as a result of culling, death, abortion, and calving. Thus, both methods will produce higher and more realistic estimates for abortion risk than are typically calculated. These measures and statistical modeling have been used to estimate the expected magnitude of abortion for dairies (ranging from 8% to 19%) and to identify associations between demographic or reproductive features of the dam and subsequent risk of abortion. Some factors discussed are effects of a previous abortion, dam gravidity and age, days open at time of conception, and season. Analytic methods also are presented for herd-based diagnosis of abortion related to infectious agents or other exposures. These methods permit estimates of the risk, or proportion, of abortions attributable to exposure to an infectious agent or to other putative abortifacient agents.

Misoprostol as the primary agent for medical abortion in a low-income urban setting

The purpose of this study was to assess the outcomes of early medical abortion in an inner-city hospital abortion service, using misoprostol as the primary agent. This was a retrospective chart review from July 2001 through December 2002. Women were eligible if they had a viable pregnancy with gestational age 8 weeks or less by transvaginal ultrasound and no medical contraindications. Two doses of 800 μg misoprostol were administered vaginally, 24 h apart. Initial follow-up was scheduled 2–3 days later. Of the 440 women who underwent medical abortion, 373 (90.8%, 95% confidence interval (CI) 88–94%) completed abortion medically, 38 (9.2%) had uterine aspiration and the remainder had incomplete or no follow-up. Of uterine aspirations, 11 were medically indicated, giving a rate of indicated aspiration of 2.7%. Gestational age, age, gravidity, parity, past abortion history, ethnic group and payer did not significantly correlate with overall rate of aspiration or rate of follow-up, but gestational age was correlated with medically indicated aspiration. Among 57 women who reported a time of tissue passage, the mean time from initial misoprostol dose was 8.5 h (95% CI 6.5–13 h).

Detection of Chlamydophila abortus in ovine milk by immunomagnetic separation-polymerase chain reaction.

The present study was carried out to investigate the presence of Chlamydophila abortus, the causative agent of ovine enzootic abortion, in milk samples collected from sheep flocks with and without the history of abortion in Eastern Turkey by means of immunomagnetic separation (IMS) in conjunction with the polymerase chain reaction (PCR). A total number of 201 milk samples collected from 10 flocks with abortion and four flocks without abortion were tested. In the analysis of the milk samples by IMS-PCR, correct amplification was obtained with three (1.5%) samples originating from one flock with abortion. In the digestion of PCR positive products by AluI, restriction profiles observed in all three samples were determined to be the same as C. abortus S26/3.

Emerging Chlamydial Infections

Chlamydiae are important intracellular bacterial pathogens of vertebrates. In the last years, novel members of this group have been discovered: Parachlamydia acanthamoebae and Simkania negevensis seems to be emerging respiratory human pathogens, while Waddlia chondrophila might be a new agent of bovine abortion. Various species have been showed to infect also the herpetofauna and fishes, and some novel chlamydiae are endosymbionts of arthropods. In addition, molecular studies evidenced a huge diversity of chlamydiae from both environmental and clinical samples, most of such a diversity could be formed by novel lineages of chlamydiae. Experimental studies showed that free-living amoebae may support multiplication of various chlamydiae, then could play an important role as reservoir/vector of chlamydial infections. Here we reviewed literature data concerning chlamydial infections, with a particular emphasis on the novely described chlamydial organisms.

Prophylactic Therapy for Migraine.

The term migraine is derived from the ancient Greek word hemicrania introduced by Galen in approximately 200 AD. However, descriptions of "sick headache" have been found dating back to as far as 3000 BC. Despite this, migraine is a condition that still remains underdiagnosed and undertreated. The development of effective abortive agents, such as the triptans, have had a significant impact on migraine management, but there still remains a substantial proportion of migraineurs in whom further medication is required in the form of preventatives. These have the potential to transform the lives of many migraine sufferers.

Natural Killer (NK) Cells Play a Critical Role in the Early Innate Immune Response to Chlamydophila abortus Infection in Mice

Chlamydophila abortus, the aetiological agent of ovine enzootic abortion, induces a strong inflammatory reaction that leads to the T helper cell (Th1) specific immune response necessary for the clearance of infection. Because the role of natural killer (NK) cells during the first stages of this response has received little attention, this study focused on determining the function of these cells in a mouse model of infection. The location of NK cells in the liver and spleen of infected mice was examined immunohistochemically with an anti-Ly49G monoclonal antibody. The number of NK cells increased during the infection both in spleen and liver. In subsequent experiments, an anti-asialo GM1 polyclonal antibody was injected to deplete the NK cells. NK-depleted mice showed a substantial increase in their susceptibility to C. abortus infection, with high mortality rates and an increased burden of bacteria in the liver. Histopathological studies showed that inflammatory foci, composed mainly of neutrophils, were greater in size and number in depleted mice, while numerous chlamydial inclusions were associated with the foci. Serum concentrations of IFN-gamma, a key cytokine in the control of C. abortus infection, were substantially reduced in the NK-depleted mice. To establish the relationship between NK cells and other components of the innate immune response, neutrophils were depleted with the RB6-8C5 antibody. These cells were shown to be crucial in the recruitment of NK cells to the inflammatory foci.

Anaplasma phagocytophila as an abortifacient agent in sheep farms from northern Spain.

Anaplasma phagocytophila as an abortifacient agent in sheep farms from northern Spain.

Relationship between the immune response and protection conferred by new designed inactivated vaccines against ovine enzootic abortion in a mouse model

Chlamydophila abortus is a gram-negative obligate intracellular bacterium and the etiological agent of ovine enzootic abortion (OEA), an economically important disease in many countries. Inactivated vaccines have been reported to induce immunity in ewes and they have been used for many years. However, some outbreaks have been reported in correctly vaccinated flocks, so it is clear that new vaccines are necessary to address adequate protection and to avoid the shedding of the microorganism. This idea lead us to design inactivated vaccines, in a previously established mouse model, evaluating different inactivation procedures and new adjuvants. To assess the protection conferred, the results were analyzed on the basis of clinical signs and the isolation of C. abortus from spleen. These findings were correlated with the immune response induced by the vaccines, as determined by the production of C. abortus-specific IFN-γ and IL-4 from splenocyte cultures and the detection of IgG isotypes in serum. BEI was found to be the best C. abortus-inactivation procedure. The inactivated vaccines adjuvated with QS-21 (QS) or Montanide 773 (M7) induced the best protection both against homologous and heterologous challenge, with an adequate (Th1-like) immune response. Finally, these selected vaccines were evaluated in a pregnant mouse model, in which they were seen to confer good protection and to avoid the C. abortus persistence in uterus after delivery. With these results, this mouse model could be considered as an adequate tool for selecting and optimizing effective vaccines against OEA.

Topiramate in the treatment of cluster headache.

Cluster headache is a well-characterized, strictly unilateral headache with cranial autonomic features and can be classified as episodic or chronic. Cluster attacks reliably are short-lived, often have a clockwise regularity, and can occur daily for weeks or months during an active cluster period. Pharmacologic treatment for this disorder can be divided into abortive and prophylactic agents. Prophylactic agents aim to quickly induce and maintain a remission. Short-term prophylaxis may be attained with the use of steroids, ergotamine, or methysergide, but these agents are not as suitable for continuous use. Verapamil and lithium commonly are used for longer periods and other agents, such as melatonin and baclofen, also are considered useful. There has been increased interest in the use of anticonvulsants for pain syndromes such as primary headache disorders. This includes topiramate use for cluster prophylaxis; a number of open-label studies have had encouraging results. This article provides an overview of topiramate and the open-label studies of this agent in the prevention of cluster headache.

Detection of IgG Antibodies against Chlamydophila abortus in Sheep with Reproductive Disorders

Travniaek M., D. Kovaaova, M.R. Bhide, P. Zubrick˘, L. âislakova:Detection of IgG Antibodies against Chlamydophila abortus in Sheep with Reproductive Disorders. Acta Vet. Brno 2003, 72: 95-99. Chlamydophila (Chl.) abortus is the most important causative agent of the enzootic abortion and other chlamydial infections of sheep. Complement fixation (CF) test is a very useful serological method as screening test, but the diagnosis can be complicated by non-specific, false positive reactions with some Gram-negative bacteria as well as with Chl. pecorum. Diagnosis can be improved by simultaneous use of indirect (i)ELISA. Moderate agreement (Kappa ‐ 0.568) between CF test and iELISA was observed in this study. We observed 36.0 % (75/208) positive samples from clinically healthy sheep and 63.2 % (91/144) in the sheep with reproductive disorders by detecting anti-Chl. abortus IgG antibodies using iELISA. When the same sera samples were investigated by CF test, only 13.9 % seropositivity was observed in clinically health sheep whereas in the group with reproductive disorders, positivity observed was 45.8%. Sensitivity and specificity of iELISA used in this study was found to be higher than CF test. Chlamydophila abortus, IgG antibodies, sheep, iELISA, CF test

Prevalence and diversity of Arcobacter spp. isolated from the internal organs of spontaneous porcine abortions in Denmark

A study was conducted to determine the prevalence and possible significance of campylobacteria in pig abortions in Denmark. Surface-cauterised liver and kidney samples from 55 aborted pig fetuses submitted to the Danish Veterinary Laboratory were taken and a sensitive isolation procedure used to examine pooled tissue samples for Campylobacter, Arcobacter and Helicobacter spp. Routine microbiological, immunological, and histopathological examinations were also performed to identify concurrent infections or histopathological changes. The abortions tested negative for established abortifacient pathogens ( Brucella, Leptospira, PPV, PRRSV), but Arcobacter spp. were recovered from 23/55 abortions. Co-infections with Streptococcus suis, Escherichia coli, and haemolytic streptococci were observed in 7/23 Arcobacter-positive fetuses, and in 4/32 Arcobacter-negative fetuses. Histopathological analyses identified placentitis, pneumonia, hepatitis and encephalitis among the study group. However, no obvious pathologic features were solely associated with Arcobacter-positive cases, nor were Arcobacter-like bacteria observed in tissue samples. Protein profile analyses of the 27 Arcobacter isolates identified 11 as A. cryaerophilus and 10 as A. skirrowii. Six strains could not be classified into any existing species and were phenotypically distinct, thus, potentially representing at least one new species. The identification results showed that multiple taxa could be found in a single fetus, and in distinct aborted fetuses from a single sow. The high prevalence of arcobacters in Danish pig abortions may account for at least some of the >90% of cases in which no established abortifacient agent is detected, but further studies are needed to define the role of each species, especially where co-infections with other bacteria are present.