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Nayeri T, Moosazadeh M, Sarvi S, Daryani A. Neospora caninum infection in aborting bovines and lost fetuses: A systematic review and meta-analysis. PLoS One 2022; 17:e0268903. [PMID: 35604902 PMCID: PMC9126370 DOI: 10.1371/journal.pone.0268903] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 05/10/2022] [Indexed: 11/19/2022] Open
Abstract
Background
Neospora caninum (N. caninum) is known to be a major cause of reproductive failure in cattle herds around the world. Therefore, the current comprehensive study was performed to estimate the global prevalence of N. caninum infection in bovines that had an abortion and aborted fetuses.
Methods
In this study, PubMed, ScienceDirect, Web of Science, Scopus, and ProQuest databases were systematically searched for relevant studies up until November 4, 2021. Pooled prevalence and corresponding 95% confidence intervals (CI) were estimated using a random effect model. Other analyzes performed on the data of this study include sensitivity analysis, publication bias test, and quality assessment.
Results
The final analyses included 71 studies conducted on 2965 abortive cattle and 4805 aborted fetuses. The overall prevalence rates of N. caninum infection in bovines that had an abortion were 47% and 1% using serological and molecular methods. Furthermore, overall prevalence rates of N. caninum infection in bovine aborted fetuses globally were 35% (95% CI: 8%–62%) and 43% (95% CI: 35%–52%) using serological and molecular methods.
Conclusions
The results of this study showed the high prevalence of N. caninum infection in bovines that had an abortion and aborted fetuses. It is hoped that the results of this study will help prevent abortion in bovines around the world and encourage further studies to determine the impact of this parasite on the occurrence of abortion that may help reduce the economic damage caused by abortion worldwide.
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Affiliation(s)
- Tooran Nayeri
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahmood Moosazadeh
- Gastrointestinal Cancer Research Center, Non-communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- * E-mail:
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2
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El-Alfy ES, Ohari Y, Shimoda N, Nishikawa Y. Genetic characterization of Neospora caninum from aborted bovine fetuses in Hokkaido, Japan. INFECTION GENETICS AND EVOLUTION 2021; 92:104838. [PMID: 33819682 DOI: 10.1016/j.meegid.2021.104838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/13/2021] [Accepted: 03/31/2021] [Indexed: 11/16/2022]
Abstract
Neospora caninum is one of the main causes of bovine abortions worldwide, including Japan. Nothing is known about the N. caninum population substructures in Japan, and only one isolate from a pregnant sheep has been studied to date. This study describes, for the first time, the genetic characterization of isolates of N. caninum implicated in cattle abortions in Japan. Brains from five aborted fetuses were successfully genotyped based on multilocus microsatellite markers. Assigned genotypes showed high frequencies of mixed alleles in the sequenced markers MS7 and MS10, raising concerns about the subpopulation structures of N. caninum infecting animals in Japan. Clustering analysis of the genotypes, together with those from a previous dataset, showed that five of the six genotypes were distinct from other clusters. Meanwhile, the remaining genotype, together with the sheep isolate from Japan, was grouped with those from Mexico and Spain. These preliminary data may indicate a complex transmission pattern of N. caninum in Japan via clonal spreading by vertical and horizontal transmission and geographically related population substructuring.
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Affiliation(s)
- El-Sayed El-Alfy
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan; Department of Parasitology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Yuma Ohari
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan; Laboratory of Parasitology, Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan
| | - Naomi Shimoda
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
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3
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Duarte PO, Oshiro LM, Zimmermann NP, Csordas BG, Dourado DM, Barros JC, Andreotti R. Serological and molecular detection of Neospora caninum and Toxoplasma gondii in human umbilical cord blood and placental tissue samples. Sci Rep 2020; 10:9043. [PMID: 32493968 PMCID: PMC7271125 DOI: 10.1038/s41598-020-65991-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 05/13/2020] [Indexed: 11/09/2022] Open
Abstract
Neosporosis primarily affects cattle and dogs and is not currently considered a zoonotic disease. Toxoplasmosis is a zoonosis with a worldwide distribution that is asymptomatic in most cases, but when acquired during pregnancy, it can have serious consequences. The seropositivity rates determined by the indirect fluorescent antibody test for Neospora caninum (N. caninum) and Toxoplasma gondii (T. gondii) were 24.3% (49 samples) and 26.8% (54 samples), respectively. PCR positivity for N. caninum was observed in two samples of cord blood (1%) using the Nc5 and ITS1 gene, positivity for T. gondii was observed in 16 samples using the primer for the B1 gene (5.5% positivity in cord blood and 2.5% positivity in placental tissue). None of the samples showed structures characteristic of tissue cysts or inflammatory infiltrate on histopathology. Significant associations were observed only between N. caninum seropositivity and the presence of domestic animals (p = 0.039) and presence of dogs (p = 0.038) and between T. gondii seropositivity and basic sanitation (p = 0.04). This study obtained important findings regarding the seroprevalence and molecular detection of N. caninum and T. gondii in pregnant women; however, more studies are necessary to establish a correlation between risk factors and infection.
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Affiliation(s)
- Pâmella Oliveira Duarte
- Programa de Pós-Graduação em Doenças Infecciosas e Parasitárias- Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brasil
| | - Leandra Marla Oshiro
- Laboratório de Biologia Molecular do Carrapato, Departamento de Sanidade Animal, Embrapa Gado de Corte, Campo Grande, MS, Brasil
| | - Namor Pinheiro Zimmermann
- Professor do Curso de Medicina Veterinária do Centro Universitário da Grande Dourados-UNIGRAN, Dourados, Brasil
| | - Bárbara Guimarães Csordas
- Bolsista de Pós-Doutorado- FUNDAPAM, Laboratório de Biologia Molecular do Carrapato, Departamento de Sanidade Animal, Embrapa Gado de Corte, Campo Grande, MS, Brasil
| | | | | | - Renato Andreotti
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Gado de Corte, Campo Grande, MS, Brasil.
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Moine E, Denevault-Sabourin C, Debierre-Grockiego F, Silpa L, Gorgette O, Barale JC, Jacquiet P, Brossier F, Gueiffier A, Dimier-Poisson I, Enguehard-Gueiffier C. A small-molecule cell-based screen led to the identification of biphenylimidazoazines with highly potent and broad-spectrum anti-apicomplexan activity. Eur J Med Chem 2014; 89:386-400. [PMID: 25462254 DOI: 10.1016/j.ejmech.2014.10.057] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 10/17/2014] [Accepted: 10/18/2014] [Indexed: 10/24/2022]
Abstract
An in vitro screening of the anti-apicomplexan activity of 51 compounds, stemming from our chemical library and from chemical synthesis, was performed. As a study model, we used Toxoplasma gondii (T. gondii), expressing β-galactosidase for the colorimetric assessment of drug activity on parasites cultivated in vitro. This approach allowed the validation of a new series of molecules with a biphenylimidazoazine scaffold as inhibitors of T. gondii growth in vitro. Hence, 8 molecules significantly inhibited intracellular replication of T. gondii in vitro, with EC50 < 1 μM, while being non-toxic for human fibroblasts at these concentrations. Most attractive candidates were then selected for further biological investigations on other apicomplexan parasites (Neospora caninum, Besnoitia besnoiti, Eimeria tenella and Plasmodium falciparum). Finally, two compounds were able to inhibit growth of four different apicomplexans with EC50 in the submicromolar to nanomolar range, for each parasite. These data, including the broad anti-parasite spectrum of these inhibitors, define a new generation of potential anti-parasite compounds of wide interest, including for veterinary application. Studies realized on E. tenella suggest that these molecules act during the intracellular development steps of the parasite. Further experiments should be done to identify the molecular target(s) of these compounds.
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Affiliation(s)
- Espérance Moine
- UMR INRA 1282 Infectiologie et Santé Publique, Recherche et Innovation en Chimie Médicinale, University François Rabelais of Tours, F-37200 Tours, France; UMR INRA 1282 Infectiologie et Santé Publique, Immunologie Parasitaire, Vaccinologie et Bio-thérapie Anti-infectieuse, University François Rabelais of Tours, F-37200 Tours, France
| | - Caroline Denevault-Sabourin
- UMR INRA 1282 Infectiologie et Santé Publique, Recherche et Innovation en Chimie Médicinale, University François Rabelais of Tours, F-37200 Tours, France.
| | - Françoise Debierre-Grockiego
- UMR INRA 1282 Infectiologie et Santé Publique, Immunologie Parasitaire, Vaccinologie et Bio-thérapie Anti-infectieuse, University François Rabelais of Tours, F-37200 Tours, France
| | - Laurence Silpa
- UMR INRA 1282 Infectiologie et Santé Publique, Recherche et Innovation en Chimie Médicinale, University François Rabelais of Tours, F-37200 Tours, France; UMR INRA 1282 Infectiologie et Santé Publique, Apicomplexes et Immunité des Muqueuses, INRA, F-37380 Nouzilly, France
| | - Olivier Gorgette
- Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, Département de Parasitologie et de Mycologie, F-75015 Paris, France
| | - Jean-Christophe Barale
- Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, Département de Parasitologie et de Mycologie, F-75015 Paris, France
| | - Philippe Jacquiet
- UMR 1225 INRA-National Veterinary School of Toulouse, Interactions hôtes-agents pathogènes, F-31076 Toulouse, France
| | - Fabien Brossier
- UMR INRA 1282 Infectiologie et Santé Publique, Apicomplexes et Immunité des Muqueuses, INRA, F-37380 Nouzilly, France
| | - Alain Gueiffier
- UMR INRA 1282 Infectiologie et Santé Publique, Recherche et Innovation en Chimie Médicinale, University François Rabelais of Tours, F-37200 Tours, France
| | - Isabelle Dimier-Poisson
- UMR INRA 1282 Infectiologie et Santé Publique, Immunologie Parasitaire, Vaccinologie et Bio-thérapie Anti-infectieuse, University François Rabelais of Tours, F-37200 Tours, France
| | - Cécile Enguehard-Gueiffier
- UMR INRA 1282 Infectiologie et Santé Publique, Recherche et Innovation en Chimie Médicinale, University François Rabelais of Tours, F-37200 Tours, France
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5
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Dubey JP, Buxton D, Wouda W. Pathogenesis of bovine neosporosis. J Comp Pathol 2006; 134:267-89. [PMID: 16712863 DOI: 10.1016/j.jcpa.2005.11.004] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 11/28/2005] [Indexed: 11/29/2022]
Abstract
The protozoan parasite Neospora caninum is a major pathogen of cattle and dogs, being a significant cause of abortion in cattle in many countries. It is one of the most efficiently transmitted parasites, with up to 90% of cattle infected in some herds. The pathogenesis of abortion due to Neospora is complex and only partially understood. Losses occur after a primary infection during pregnancy but more commonly as the result of recrudescence of a persistent infection during pregnancy. Parasitaemia is followed by invasion of the placenta and fetus. It is suggested that abortion occurs when primary parasite-induced placental damage jeopardises fetal survival directly or causes release of maternal prostaglandins that in turn cause luteolysis and abortion. Fetal damage may also occur due to primary tissue damage caused by the multiplication of N. caninum in the fetus or due to insufficient oxygen/nutrition, secondary to placental damage. In addition, maternal immune expulsion of the fetus may occur associated with maternal placental inflammation and the release of maternal pro-inflammatory cytokines in the placenta. Thus N. caninum is a primary pathogen capable of causing abortion either through maternal placental inflammation, maternal and fetal placental necrosis, fetal damage, or a combination of all three. The question of how N. caninum kills the fetus exposes the complex and finely balanced biological processes that have evolved to permit bovine and other mammalian pregnancies to occur. Defining these immunological mechanisms will shed light on potential methods of control of bovine neosporosis and enrich our understanding of the continuity of mammalian and protozoal survival.
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Affiliation(s)
- J P Dubey
- Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, BARC-East, Building 1001, 10300 Baltimore Avenue, Beltsville, MD 20705-2350, USA
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6
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Torres MP, Ortega YR. Neospora caninum antibodies in commercial fetal bovine serum. Vet Parasitol 2006; 140:352-5. [PMID: 16697531 DOI: 10.1016/j.vetpar.2006.03.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 02/02/2006] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
The protozoan parasite Neospora caninum is a major cause of abortion in cattle throughout the world. In the process of propagating Neospora in vitro and producing specific antibodies for development of diagnostic assays in the food supply, our laboratory identified the presence of bovine antibodies to N. caninum in fetal bovine sera. The sera were produced commercially and preferentially recommended for tissue culture use and monoclonal antibody production. Seventeen different fetal bovine serum samples of different grades and from four different companies were examined for the presence of total IgG, IgG1, IgG2, and IgM specific for N. caninum. All of the tested serum samples recognized N. caninum specific bands on Western blot. Low IgG serum also recognized these antigens but with lower intensity. Antibody response was also evaluated using a commercially available ELISA kit for N. caninum.
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Affiliation(s)
- Maria P Torres
- Center for Food Safety, The University of Georgia, Griffin, GA 30223, USA
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Koiwai M, Hamaoka T, Haritani M, Shimizu S, Zeniya Y, Eto M, Yokoyama R, Tsutsui T, Kimura K, Yamane I. Nationwide seroprevalence of Neospora caninum among dairy cattle in Japan. Vet Parasitol 2005; 135:175-9. [PMID: 16207513 DOI: 10.1016/j.vetpar.2005.08.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 08/15/2005] [Accepted: 08/30/2005] [Indexed: 11/22/2022]
Abstract
Serum samples from 2420 clinically healthy dairy cattle, randomly selected from stored sera in 18 districts of Japan, were tested for the presence of Neospora caninum antibodies using an indirect fluorescent antibody test (titer > or =1:200). Nationwide seroprevalence is estimated at 5.7% (139/2420). Seropositive cattle were detected in all surveyed districts despite the evidence of confirmed case reports of bovine neosporosis, showing that N. caninum is widely distributed throughout Japan. Age-specific seroprevalence did not increase with cattle age, suggesting that Neospora infection is likely to be transmitted vertically rather than horizontally in Japan. Considering that N. caninum seropositive cows are thought to be more likely to abort, substantial fetal losses may be induced by N. caninum infection in Japan. Devising strategies are needed to reduce the economic impact on the Japanese dairy industry. This is the first study to investigate the nationwide seroprevalence of N. caninum in cattle in Asia.
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Affiliation(s)
- Masahiro Koiwai
- Department of Diagnosis and Research, Animal Quarantine Service, Ministry of Agriculture, Forestry and Fisheries, Haramachi 11-1, Yokohama 235-0008, Japan.
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8
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Collantes-Fernández E, Rodríguez-Bertos A, Arnáiz-Seco I, Moreno B, Aduriz G, Ortega-Mora LM. Influence of the stage of pregnancy on Neospora caninum distribution, parasite loads and lesions in aborted bovine foetuses. Theriogenology 2005; 65:629-41. [PMID: 16023188 DOI: 10.1016/j.theriogenology.2005.06.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Revised: 06/02/2005] [Accepted: 06/06/2005] [Indexed: 10/25/2022]
Abstract
In the present work we have studied in Neospra caninum aborted bovine foetuses the influence of foetal age (first, second and third gestational periods) on parasite distribution by nested PCR, parasite loads by real-time PCR and N. caninum associated lesions. For this purpose, a total of 220 aborted foetuses were analysed and detection of N. caninum infection was accomplished by nested-PCR in brain, heart and liver, detecting the presence of the parasite in 72 (32.7%) bovine foetuses. When the different age classes were compared, parasite DNA-detectability in heart and liver was reduced over time of gestation (P < 0.05, Fisher F-test). N. caninum distribution, parasite loads and lesions were studied on 34 out of 72 N. caninum-infected foetuses selected according to the stage of pregnancy and organs recovered. A higher number of positive-PCR tissue samples were observed in the foetuses corresponding to the first and second pregnancy periods. In the last trimester, the parasite could only be detected in the brain and, sporadically, in the diaphragm, heart and lymph nodes. The parasite loads decreased during pregnancy and the foetuses from the first period had higher parasite burdens in brain, heart, kidney and lung (P < 0.05, Kruskal-Wallis H-test) than in those corresponding to the other two trimesters of pregnancy. In addition, the observed lesions were more severe in foetuses from the first and second pregnancy periods than those from the third period (P > 0.05, Kruskal-Wallis H-test). Our results confirm the influence of N. caninum foetal age on pathogenesis in natural N. caninum infections.
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Affiliation(s)
- Esther Collantes-Fernández
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
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9
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Koiwai M, Hamaoka T, Haritani M, Shimizu S, Tsutsui T, Eto M, Yamane I. Seroprevalence of Neospora caninum in dairy and beef cattle with reproductive disorders in Japan. Vet Parasitol 2005; 130:15-8. [PMID: 15893065 DOI: 10.1016/j.vetpar.2005.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2005] [Indexed: 11/27/2022]
Abstract
Serum samples from 145 dairy and 65 beef cattle with reproductive disorders and 54 normally calving dairy cattle (controls) in Japan were tested for presence of Neospora caninum antibodies by use of an indirect fluorescent antibody test (IFAT, titer 1:200). Overall, seroprevalence of N. caninum was significantly higher (P < 0.001) in dairy cattle (20.0%, 29/145) than in beef cattle (1.5%, 1/65). In cattle which aborted, seroprevalence of N. caninum was significantly higher (P = 0.041) in dairy cattle (26.1%, 23/88, compared with controls (3.7%, 2/54)) than in beef cattle (5.0%, 1/20), indicating that neosporosis might be a more common problem in dairy cattle than in beef cattle in Japan. Seropositive cattle were 9.2 times more likely to abort compared to seronegative cows. Abortions associated with N. caninum seropositivity in this study were most frequently observed in the second trimester, and the mean gestational age of the fetuses aborted from seropositive dams was 5.7 months. In conclusions, N. caninum seems to be causing serious economic losses in the dairy industry in Japan. This is the first report on an objective comparison of seroprevalence of dairy and beef cattle with reproductive disorders in Asia.
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Affiliation(s)
- Masahiro Koiwai
- Department of Diagnosis and Research, Animal Quarantine Service, Ministry of Agriculture, Forestry and Fisheries, Haramachi 11-1, Yokohama 235-0008, Japan.
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10
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Macaldowie C, Maley SW, Wright S, Bartley P, Esteban-Redondo I, Buxton D, Innes EA. Placental pathology associated with fetal death in cattle inoculated with Neospora caninum by two different routes in early pregnancy. J Comp Pathol 2005; 131:142-56. [PMID: 15276854 DOI: 10.1016/j.jcpa.2004.02.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Accepted: 02/23/2004] [Indexed: 11/19/2022]
Abstract
Pregnant cattle were inoculated with N. caninum strain NC-1 tachyzoites intravenously (iv) (group 1, n = 8) or subcutaneously (sc) (group 2, n = 8) at 70 days' gestation. Control animals (group 3; n = 8) received uninfected Vero cells iv. Two animals from each group were killed at 14, 28, 42 and 56 days post-inoculation (dpi). Fetal mortality was 100% and 50%, respectively, in groups 1 and 2 from 28 dpi. In group 1 foci of degenerative fetal placental villi were observed at 14 dpi, with clusters of N. caninum tachyzoites in the affected mesenchyme. There was also inflammation of maternal septal tissues, with necrotic cell debris and serum exudate at the interstitium. At 28 dpi pregnancy had ended and the fetal cotyledons had become detached from the maternal caruncles. Immunohistochemically, particulate N. caninum antigen was detected in the cotyledons. At 42 and 56 dpi, fetal tissues had disappeared, the caruncles were greatly reduced in size, and the uterine epithelium had been largely restored. In group 2, lesions were either severe or absent ("all or nothing" response). In one animal carrying a dead fetus at 28 dpi, placentitis was much more severe than that seen in group 1 at 14 dpi. Lesions contained neutrophils, eosinophils and N. caninum antigen. In animals carrying dead fetuses at 42 and 56 dpi, fetal remains were found and the cotyledons contained N. caninum antigen. Antigen was also detected in fetal tissues. No significant pathological changes were detected in group 2 animals carrying live fetuses or any animal in group 3. Thus, N. caninum administered iv or sc in early pregnancy resulted in rapid fetal death, with parasite-associated lesions in the placenta and fetus. Of the two inoculation routes, the intravenous induced the more acute placental lesions and greater mortality.
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Affiliation(s)
- C Macaldowie
- Division of Virology, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 OPZ, UK
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11
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Abstract
Neospora caninum is a recently recognized protozoan parasite of animals, which, until 1988, was misdiagnosed as Toxoplasma gondii. Neospora caninum or Neospora-like parasites, here discussed by J.P. Dubey and David Lindsay, cause paralysis and death in dogs and neonatal mortality and abortion in cattle, sheep, goats and horses.
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Affiliation(s)
- J P Dubey
- US Department of Agriculture, BARC-East, Beltsville, MD 20705-2350, USA
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12
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Abstract
Since its first description in dogs in 1984, the protozoan parasite Neospora caninum has been found to infect a wide range of animals, worldwide. In cattle, N. caninum has particular significance as a cause of abortion in which persistence of infection in the mother, recrudescence of the parasite during pregnancy, and the vulnerability of the placenta and foetus to invasion are important features. This article discusses how Neospora invades cells, how it infects and causes disease in several animal species, and particularly how it has evolved a special niche in cattle and dogs that ensures its survival.
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Affiliation(s)
- David Buxton
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, UK.
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13
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Kim JH, Lee JK, Lee BC, Park BK, Yoo HS, Hwang WS, Shin NR, Kang MS, Jean YH, Yoon HJ, Kang SK, Kim DY. Diagnostic survey of bovine abortion in Korea: with special emphasis on Neospora caninum. J Vet Med Sci 2002; 64:1123-7. [PMID: 12520105 DOI: 10.1292/jvms.64.1123] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Causes of bovine abortion were surveyed in Korea within a designated period from the cases submitted to the Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University. One hundred and eighty aborted fetuses and maternal sera were evaluated by necropsy, histopathology, bacteriology, virology, PCR, and serologic tests. The causes of abortion were identified in 108 (60%) cases, of which 38 (21.1%) were due to the infection with Neospora caninum. None of the 38 cases showed any co-infection with either virus or bacteria. Viral and bacterial causes were diagnosed in 28 (15.5%) and 13 (7.2%) aborted fetuses, respectively. Non-infectious causes such as multiple pregnancy, maternal weakness or torsion of umbilical cord were observed in 22 (12.3%) cases. Results of the present study suggest that N. caninum is believed to be the leading cause of bovine abortion in Korea. Thus, more attention should be paid to this emerging disease in Korea. However, the causes of many aborted fetuses remain undiagnosed in this study. Therefore, this enigma should be clarified through further studies such as chromosomal analysis.
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Affiliation(s)
- J-H Kim
- National Veterinary Research and Quarantine Service, Anyang, Korea
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14
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De Meerschman F, Speybroeck N, Berkvens D, Rettignera C, Focant C, Leclipteux T, Cassart D, Losson B. Fetal infection with Neospora caninum in dairy and beef cattle in Belgium. Theriogenology 2002; 58:933-45. [PMID: 12212893 DOI: 10.1016/s0093-691x(02)00934-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neospora caninum is a protozoan parasite, which causes fetal and neonatal mortality in livestock and companion animals. In 224 abortions in Belgian cattle, different diagnostic methods were used to demonstrate infection, and the presence of N. caninum. An indirect fluorescent antibody test (IFAT) was used to analyze fetal and maternal sera and immunohistochemistry (IHC) was performed when lesions consistent with neosporosis were observed in the brain, heart or liver. Twenty dairy cattle sera out of 70 (29%) and 13 beef cattle sera out of 93 (14%) were positive by IFAT. A positive titer to N. caninum was found in seven and three fetuses born to beef and dairy cows, respectively. Lesions consistent with N. caninum infection were observed in 17 fetuses. Of nine positive beef fetuses, five were confirmed by IHC while, all but one dairy fetus were confirmed using the same technique. Age had no influence on the serological status of the mother (P = 0.486) whereas husbandry system had a borderline influence (P = 0.082). However, a strong association (P = 0.004) between the level of antibodies in the dam and the occurrence of lesions in the fetus was observed and lesions were more prominent in dairy than in beef fetuses. Additionally, the distribution of intra-cerebral lesions was more extensive in dairy than in beef fetuses (P < 0.0001). Age and serological status of the fetus were found to influence the occurrence of lesions in beef fetuses (both P < 0.001) but no such significant relationships could be demonstrated in dairy fetuses. The study indicated that N. caninum must be considered as an important cause of bovine abortion in Belgium.
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Affiliation(s)
- F De Meerschman
- Laboratory of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, Liège, Belgium.
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15
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Morales E, Trigo FJ, Ibarra F, Puente E, Santacruz M. Neosporosis in Mexican dairy herds: lesions and immunohistochemical detection of Neospora caninum in fetuses. J Comp Pathol 2001; 125:58-63. [PMID: 11437517 DOI: 10.1053/jcpa.2001.0477] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Of 211 aborted bovine fetuses collected from Mexican dairy herds between January 1996 and March 1999, 73 showed microscopical lesions consistent with neosporosis. Of these 73 fetuses, 58 (79%) showed lymphocytic myocarditis, 39 (53%) showed microgliosis and multifocal necrosis in the brain, 39 (53%) showed lymphocytic hepatitis, and 19 (26%) showed lymphocytic myositis. Immunohistochemical examination of brain, myocardium and liver from 53 of the same 73 fetuses demonstrated Neospora caninum antigens in 41 (77%), of which 19 (46%) gave positive results in one of the three sites, 15 (37%) in two, and seven (17%) in three. The results indicated the presence of neosporosis in a number of the main dairy farming regions of Mexico.
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Affiliation(s)
- E Morales
- Departamento de Patología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónama de México, 04510, México, D.F
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16
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Noda Y, Yokoyama H, Katsuki T, Kurashige S, Uchinuno Y, Narita M. Demonstration of Akabane virus antigen using immunohistochemistry in naturally infected newborn calves. Vet Pathol 2001; 38:216-8. [PMID: 11280378 DOI: 10.1354/vp.38-2-216] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eight newborn calves showing ataxia were necropsied and examined histologically. Six of seven cerebrospinal fluid samples collected from these animals had neutralizing antibody for Akabane virus (AKV). All examined calves had nonsuppurative encephalomyelitis, localized mainly in the midbrain and spinal cord. Corresponding to the encephalitic lesion, AKV antigen was demonstrated in neuroglial cells in the brain stem and neuronal cells in the ventral horn of the spinal cord. This is the first study to demonstrate AKV antigen by immunohistochemistry in naturally infected newborn calves.
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Affiliation(s)
- Y Noda
- Byochika Livestock Hygiene Service Center, Fukuoka, Japan
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17
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Shibahara T, Kokuho T, Eto M, Haritani M, Hamaoka T, Shimura K, Nakamura K, Yokomizo Y, Yamane I. Pathological and immunological findings of athymic nude and congenic wild type BALB/c mice experimentally infected with Neospora caninum. Vet Pathol 1999; 36:321-7. [PMID: 10421099 DOI: 10.1354/vp.36-4-321] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neospora is a cyst-forming coccidian parasite that causes abortions and neuromuscular disorders in a wide variety of mammals. Japanese bovine isolate JPA1 was inoculated intraperitoneally into BALB/c nu/ nu (athymic nude) and BALB/c (congenic wild type) female mice to examine the distribution of parasites and resistance mechanisms to Neospora infection. All the athymic nude mice died within 28 days after intraperitoneal injection of 2 x 10(5) JPA1 tachyzoites, whereas all the congenic wild type mice survived without exhibiting any clinical signs. Tachyzoites were identified in the uterus and pancreas and later spread to many other organs. Most tachyzoites identified in the necrotic foci were localized in the epithelium of the venules and capillaries. Nude mice developed high level of serum interferon-gamma and interleukin-6 as infection proceeded. Inflammatory response to Neospora infection might be mediated by Th1-type dependent cellular immunity.
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Affiliation(s)
- T Shibahara
- National Institute of Animal Health, Ministry of Agriculture, Forestry and Fisheries, Tsukuba-shi, Ibaraki, Japan.
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18
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Yamane I, Shibahara T, Kokuho T, Shimura K, Hamaoka T, Haritani M, Conrad PA, Park CH, Sawada M, Umemura T. An improved isolation technique for bovine Neospora species. J Vet Diagn Invest 1998; 10:364-8. [PMID: 9786527 DOI: 10.1177/104063879801000411] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- I Yamane
- National Institute of Animal Health, Ibaraki, Japan
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19
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Sawada M, Park CH, Kondo H, Morita T, Shimada A, Yamane I, Umemura T. Serological survey of antibody to Neospora caninum in Japanese dogs. J Vet Med Sci 1998; 60:853-4. [PMID: 9713815 DOI: 10.1292/jvms.60.853] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prevalence of antibody to Neospora caninum (NC) in Japanese dogs were examined. The antibody was positive in 15 of 48 dogs (31.3%) reared in the dairy farms that had case of the abortions due to NC infection or had the cattle seropositive to NC, whereas the prevalence was 7.1% (14 of 198 dogs) among the dogs kept in urban areas. In one dog breeder, all 17 Shetland sheepdogs older than 7 months were seropositive, and one pup was diagnosed as neosporosis 2 months before the first serological examination. The antibody titers of the dogs kept at this breeder were almost unchanged for 1.5 years. Serological evidence of the dogs in the dairy farms and urban areas indicates the transmission of NC between dogs and cattle. Also serological results of the dogs in one breeder may suggest the potential horizontal transmission among dogs.
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Affiliation(s)
- M Sawada
- Laboratory of Comparative Pathology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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20
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Buxton D, Maley SW, Wright S, Thomson KM, Rae AG, Innes EA. The pathogenesis of experimental neosporosis in pregnant sheep. J Comp Pathol 1998; 118:267-79. [PMID: 9651804 DOI: 10.1016/s0021-9975(07)80003-x] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Three groups of eight pregnant sheep were inoculated with tachyzoites of the NCl isolate of Neospora caninum at 45 (group 1), 65 (group 2) or 90 (group 3) days' gestation. A further six animals (group 4) served as controls. Fourteen of the infected ewes developed a fever, which in two cases was biphasic. In six ewes in group 1, the fetuses died and were resorbed, and in the other two the fetuses were aborted. In group 2, one ewe resorbed her fetus, six aborted dead fetuses and one produced a live lamb. In group 3, six ewes aborted and two produced one live and one stillborn lamb each. Thus, the stage of gestation influenced the outcome of infection. All but one of the ewes "seroconverted", as shown by enzyme-linked immunosorbent assay, and 10 of 13 fetal sera examined by an indirect immunofluorescent antibody test were positive. The polymerase chain reaction was also used to detect DNA of N. caninum in aborted tissues. Immunohistochemical examination showed that the parasite had invaded the placentas of all cases examined, displaying an apparent predilection for fetal chorionic epithelium and fetal placental blood vessels, as well as inducing thrombosis in some maternal caruncular blood vessels. Organisms were associated with fetal vasculitis, focal degeneration and inflammation of the chorioallantois, and widespread, severe focal necrosis in the placentome. Characteristic lesions were seen in the fetal brains, in addition to focal leucomalacia, thought to be due to anoxia resulting from the placental damage. The six control sheep in group 4 remained clinically healthy and produced normal uninfected lambs.
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Affiliation(s)
- D Buxton
- Moredun Research Institute, International Research Centre, Penicuik, Midlothian
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21
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Smith CR, McGowan MR, McClintock CS, Corney BG, Ketterer PJ, Smythe L, Ward W. Experimental Leptospira borgpetersenii serovar hardjo infection of pregnant cattle. Aust Vet J 1997; 75:822-6. [PMID: 9404618 DOI: 10.1111/j.1751-0813.1997.tb15663.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To observe the effect upon the foetus of experimental infection of pregnant cattle with Leptospira borgpetersenii serovar hardjo. DESIGN A disease transmission study using pregnant cattle. PROCEDURE Fourteen heifers serologically negative to L hardjo were artificially inseminated and later challenged with a north-Queensland isolate of L hardjo by conjunctival inoculation. The heifers were serologically monitored and their urine examined for the presence of leptospires using culture and fluorescent-antibody tests at appropriate intervals. Elective caesarean sections were performed on pregnant heifers at 6.5 weeks after the challenge. Foetuses were examined using serological, histopathological, microbiological and fluorescent-antibody tests. RESULTS Ten of the heifers became pregnant, but three subsequently aborted before challenge. After challenge, all 14 heifers seroconverted and L hardjo was isolated from the urine of 6 of the 7 pregnant heifers. No evidence of foetal L hardjo infection was detected. Two of the foetuses had histopatho-logical lesions consistent with Neospora sp infection. CONCLUSION It is likely that the isolate of L hardjo used in this study does not normally infect the foetus. Neospora sp may be a more significant cause of bovine reproductive wastage.
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Affiliation(s)
- C R Smith
- Dayboro Veterinary Surgery, School of Veterinary Science, University of Queensland
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22
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Yamane I, Kokuho T, Shimura K, Eto M, Shibahara T, Haritani M, Ouchi Y, Sverlow K, Conrad PA. In vitro isolation and characterisation of a bovine Neospora species in Japan. Res Vet Sci 1997; 63:77-80. [PMID: 9368961 DOI: 10.1016/s0034-5288(97)90162-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Eleven aborted bovine fetuses and five calves suspected as having neosporosis were necropsied and tissues from these animals were inoculated into bovine cardiopulmonary aortic endothelial cells and monkey kidney cells and maintained at 37 degrees C with 5 per cent CO2. Neospora tachyzoites were observed in one cell 49 days after inoculation. The isolated parasite (JPA1) was morphologically identical to the previously reported bovine Neospora species (BPA1) and confirmed by its strong antigenic reactivity with bovine control antisera to Neospora species and its lack of reactivity with Toxoplasma gondii and Sarcocystis cruzi antisera. This is the first bovine Neospora species isolate in Asia and further studies with this isolate are now expected.
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Affiliation(s)
- I Yamane
- National Institute of Animal Health, Ibaraki, Japan
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23
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Daft BM, Barr BC, Collins N, Sverlow K. Neospora encephalomyelitis and polyradiculoneuritis in an aged mare with Cushing's disease. Equine Vet J 1997; 29:240-3. [PMID: 9234020 DOI: 10.1111/j.2042-3306.1997.tb01678.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- B M Daft
- California Veterinary Diagnostic Laboratory System, School of Veterinary Medicine, University of California, Davis 95616, USA
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24
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Wouda W, Moen AR, Visser IJ, van Knapen F. Bovine fetal neosporosis: a comparison of epizootic and sporadic abortion cases and different age classes with regard to lesion severity and immunohistochemical identification of organisms in brain, heart, and liver. J Vet Diagn Invest 1997; 9:180-5. [PMID: 9211238 DOI: 10.1177/104063879700900212] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Eighty bovine fetuses with confirmed neosporosis were used to score lesion severity and presence of parasites in brain, heart, and liver. A comparison was made between epizootic and sporadic abortion cases. The possible influence of fetal age was also investigated. Histologic lesions of multifocal encephalitis, myocarditis, and periportal hepatitis with or without focal hepatocellular necrosis were almost always observed. Neospora caninum tachyzoites were identified immunohistochemically in 85% of the brains, 14% of the hearts, and 26% of the livers. Tissue cysts were observed in 21% of the brains. Significant differences between epizootic and sporadic abortion cases were found only in the liver. Hepatic lesions were more prominent and N. caninum tachyzoites were observed more frequently and in higher numbers in epizootic cases. Examination by immunohistochemistry of the liver in addition to the brain can be highly contributive diagnostically, particularly in epizootic cases. There were no significant age-related differences except for a higher presence of tachyzoites in the hearts of younger fetuses (3-4 months gestational age).
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Affiliation(s)
- W Wouda
- Animal Health Service, Drachten, The Netherlands
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25
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Abstract
Neospora caninum is a recently recognized protozoan parasite of animals, which until 1988 was misidentified as Toxoplasma gondii. Its life cycle is unknown. Transplacental transmission is the only recognized mode of transmission. It has a wide host range, but its zoonotic potential is unknown. Neosporosis is a major cause of abortion in cattle in many countries. It is also an important cause of neuromuscular paralysis in dogs. This paper reviews information on parasite structure, life cycle, biology, clinical signs, diagnosis, treatment and control.
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Affiliation(s)
- J P Dubey
- Parasite Biology and Epidemiology Laboratory, US Department of Agriculture, BARC-East, Beltsville, MD 20705-2350, USA.
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26
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Graham DA, Smyth JA, McLaren IE, Ellis WA. Stillbirth/perinatal weak calf syndrome: serological examination for evidence of Neospora caninum infection. Vet Rec 1996; 139:523-4. [PMID: 8953695 DOI: 10.1136/vr.139.21.523] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- D A Graham
- Veterinary Sciences Division, Department of Agriculture for Northern Ireland, Stormont, Belfast
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27
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McAllister MM, McGuire AM, Jolley WR, Lindsay DS, Trees AJ, Stobart RH. Experimental neosporosis in pregnant ewes and their offspring. Vet Pathol 1996; 33:647-55. [PMID: 8952023 DOI: 10.1177/030098589603300603] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Six groups of six pregnant ewes each were inoculated with 170,000 or 1,700,000 tachyzoites of Neospora caninum on gestation day 65, 90, or 120. All ewes seroconverted, and none showed signs of illness other than abortion. Regardless of the inoculum dose, all ewes inoculated on gestation day 65 aborted; ewes inoculated on gestation day 90 aborted, gave birth to weak lambs, or gave birth to clinically normal lambs; and all ewes inoculated on gestation day 120 gave birth to clinically normal lambs. Using an immunohistological procedure that stains bradyzoites, we observed protozoal cysts in brains of 11 of 29 (38%) aborted fetuses, in one of four (25%) weak lambs, and in seven of 18 (39%) clinically normal lambs. Cysts were not observed in extraneural tissues from two clinically normal lambs that had cysts in the brain. No evidence of infection was observed in tissues of five ewes examined using an immunohistological procedure that stains N. caninum tachyzoites and bradyzoites. Multifocal nonsuppurative encephalitis was observed in 46 of 51 (90%) aborted, weak, or clinically normal lambs. Cerebral necrosis, dystrophic mineralization, and meningitis were also commonly identified in live and aborted lambs (even when severely autolyzed). Nonsuppurative, necrotizing placentitis was observed in 15 of 17 (88%) placentas. Nonsuppurative myositis was common in fetuses but not in live lambs. Inflammation occurred less frequently in liver and lung. Clinical and pathological features of neosporosis in sheep closely resemble those of bovine neosporosis and ovine toxoplasmosis. Although abortion caused by naturally occurring neosporosis in sheep has not been reported, diagnosticians should carefully distinguish between neosporosis and toxoplasmosis in cases of ovine protozoal abortion unless future investigations exclude the likelihood of naturally acquired neosporosis in sheep.
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Affiliation(s)
- M M McAllister
- University of Wyoming, College of Agriculture, Department of Veterinary Sciences, Laramie, USA
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28
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McAllister MM, Huffman EM, Hietala SK, Conrad PA, Anderson ML, Salman MD. Evidence suggesting a point source exposure in an outbreak of bovine abortion due to neosporosis. J Vet Diagn Invest 1996; 8:355-7. [PMID: 8844580 DOI: 10.1177/104063879600800313] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A Holstein dairy farm suffered an abortion outbreak due to neosporosis. Abortion losses were > 18%. Cows with the highest Neospora antibody titers were at the greatest risk of aborting. Mummified fetuses were found after the 43rd day of the outbreak. The epidemic curve was suggestive of a point source exposure, which is consistent with the hypothesis that Neospora can be spread by a definitive host.
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Affiliation(s)
- M M McAllister
- California Veterinary Diagnostic Laboratory System, Tulare 93274, USA
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29
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Lally NC, Jenkins MC, Dubey JP. Evaluation of two Neospora caninum recombinant antigens for use in an enzyme-linked immunosorbent assay for the diagnosis of bovine neosporosis. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1996; 3:275-9. [PMID: 8705668 PMCID: PMC170329 DOI: 10.1128/cdli.3.3.275-279.1996] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Neospora caninum is a recently described apicomplexan parasite which causes paralysis and death in dogs. Neospora parasites also cause abortion and neonatal morbidity in cattle, sheep, goats, and horses, and neosporosis is emerging as an important cause of bovine abortion worldwide. The purpose of this study was to identify N. caninum cDNA clones encoding antigens that would be useful for the immunodiagnosis of bovine neosporosis. Two N. caninum tachyzoite cDNA clones expressing antigens that were recognized by serum from naturally and experimentally infected cattle were identified. The DNA sequences of these clones were determined, and the inserts were subcloned into the plasmid expression vector pTrcHisB. Both recombinant antigens, expressed as fusion proteins with a His6 tag, were purified on a nickel-chelating affinity column and evaluated in separate enzyme-linked immunosorbent assays (ELISAs). Both recombinant antigen ELISAs were capable of distinguishing between sera from Neospora-infected cows and sera from uninfected control cows. Furthermore, both assays were able to detect an antibody response in animals that were experimentally inoculated with N. caninum. Neither antigen showed evidence of cross-reactivity with serum from animals inoculated with the closely related parasites Toxoplasma gondii, Sarcocystis cruzi, Sarcocystis hominis, and Sarcocystis hirsuta.
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Affiliation(s)
- N C Lally
- Parasite Immunobiology Laboratory, USDA Agricultural Research Service, Beltsville, Maryland 20705, USA
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30
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Anderson ML, Barr BC, Conrad PA. Protozoal causes of reproductive failure in domestic ruminants. Vet Clin North Am Food Anim Pract 1994; 10:439-61. [PMID: 7728629 DOI: 10.1016/s0749-0720(15)30531-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Protozoan parasites are a significant cause of abortion and infertility in domestic ruminants. Toxoplasma gondii, a widespread cause of abortion in sheep and goats, and Sarcocystis spp., which cause a common, frequently asymptomatic infection of domestic ruminants, both have a two-host life cycle. Carnivorous definitive hosts spread the infection through their feces and domestic ruminants are intermediate hosts. A similar, recently recognized protozoa, Neospora sp., has emerged as an important cause of reproductive disease, especially as an abortifacient in dairy cattle. Neospora is presumed to also have a two-host life cycle, although the definitive host(s) has not been identified. The venereally transmitted Tritrichomonas foetus is an important cause of pregnancy loss in naturally bred cattle throughout the world. In the absence of effective methods for vaccination or treatment, control of these parasites is based on management procedures to reduce infection and transmission.
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Affiliation(s)
- M L Anderson
- California Veterinary Diagnostic Laboratory, Davis
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31
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Barr BC, Rowe JD, Sverlow KW, BonDurant RH, Ardans AA, Oliver MN, Conrad PA. Experimental reproduction of bovine fetal Neospora infection and death with a bovine Neospora isolate. J Vet Diagn Invest 1994; 6:207-15. [PMID: 8068753 DOI: 10.1177/104063879400600212] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Studies were conducted to determine the pathogenic potential of the recently isolated bovine Neospora protozoa (BPA-1) for the bovine fetus. Cows chosen for study had Neospora titers < 160 using an indirect immunofluorescent antibody (IFA) test. Four experimental groups were studied. In group 1, 2 fetuses were inoculated in utero at 118 days gestation with culture-derived Neospora tachyzoites. A pregnant control cow was housed in the same pen, observed daily and screened serologically for evidence of exposure to Neospora. In group 2, 2 cows were infected with Neospora tachyzoites at 138 or 161 days gestation, and 1 control cow was given uninfected cell culture suspension simultaneously at 154 days gestation. Groups 3 (85 days gestation) and 4 (120 days gestation) each consisted of 2 cows infected with Neospora tachyzoites and 1 control cow given uninfected material at the same stage of gestation. Dead fetuses were surgically removed from the infected cows in group 1 on postinfection day (PID) 17. The histopathology was compatible with protozoal fetal infection, and protozoa were identified by immunohistochemistry. Viable fetuses were removed surgically from cows in group 2 on PID 28-30. The histopathology was compatible with protozoal fetal infection, protozoa were identified by immunoperoxidase techniques, and Neospora tachyzoites were reisolated in vitro from tissues of the 2 infected fetuses. In groups 3 and 4, the control fetus and 1 infected fetus were removed surgically between PID 26 and PID 33. The remaining infected cows were observed until fetal death or abortion occurred.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B C Barr
- California Veterinary Diagnostic Laboratory System, School of Veterinary Medicine, University of California, Davis 95616
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32
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Conrad PA, Sverlow K, Anderson M, Rowe J, BonDurant R, Tuter G, Breitmeyer R, Palmer C, Thurmond M, Ardans A. Detection of serum antibody responses in cattle with natural or experimental Neospora infections. J Vet Diagn Invest 1993; 5:572-8. [PMID: 8286457 DOI: 10.1177/104063879300500412] [Citation(s) in RCA: 167] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Parasite-specific antibody responses were detected using an indirect fluorescent antibody (IFA) test in cattle that were naturally or experimentally infected with Neospora parasites. The test was developed using Neospora tachyzoites isolated from an aborted bovine fetus and grown in bovine cell cultures (isolate BPA1). In all cases, infections were confirmed by the identification of Neospora tachyzoites and/or bradyzoite cysts in fetal or calf tissues using an immunoperoxidase test procedure. Fifty-five naturally infected cows that aborted Neospora-infected fetuses had titers of 320-5,120 at the time of abortion. The titer of 6 cows that were serologically monitored over a prolonged period decreased to 160-640 within 150 days after they aborted infected fetuses. Two of the cows showed an increase in their Neospora titers during their subsequent pregnancy, and they gave birth to congenitally infected calves that had precolostral titers of 10,240-20,480. Postcolostral titers of these calves and of 4 other calves with congenital Neospora infections were all > or = 5,120, whereas calves with no detectable parasites had titers < or = 160. Two pregnant heifers that were experimentally infected with the BPA1 isolate at approximately 120 days gestation seroconverted to Neospora antigens within 9 days and developed peak titers of 5,120 and 20,480 within 32 days of infection. The fetus taken by caesarean section 32 days postinfection from 1 heifer and the full-term calf born to the other had Neospora titers of 640 and 10,240, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P A Conrad
- School of Veterinary Medicine, University of California, Davis 95616
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