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Lagomarsino H, Scioli A, Rodríguez A, Armendano J, Fiorani F, Bence Á, García J, Hecker Y, Gual I, Cantón G, Odeón A, Campero C, Moore D. Controlling Endemic Neospora caninum-Related Abortions in a Dairy Herd From Argentina. Front Vet Sci 2019; 6:446. [PMID: 31921907 PMCID: PMC6920123 DOI: 10.3389/fvets.2019.00446] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/26/2019] [Indexed: 11/13/2022] Open
Abstract
After diagnosis of endemic abortions due to neosporosis in a commercial dairy farm, routes of Neospora caninum-transmission were evaluated in order to choose the best strategy for reducing its seroprevalence and related abortions. Fifty two dam-calf pairs were bled at parturition. Additionally, 22 female calves were also sampled at regular 3 month intervals until 18-22 months. N. caninum specific antibodies were assayed by IFAT. Serum samples were tested at a dilution 1:25 for calves before colostrum intake and heifers before mating and 1:100 for multiparous cows. Only serum samples from IFAT seropositive cattle involved in the evaluation of the routes of transmission were assessed by a commercial IgG avidity ELISA. Seropositive cows or heifers were artificially inseminated with semen from Hereford bulls. The progenies from these female animals were sent to a feed lot to produce meat. Different generalized linear models (GLM) were used to study the relationship between abortion, age category, and serostatus. Seropositive heifers were more likely to have a record of abortion (OR 2.7; 95% CI 1.6-4.7). Vertical transmission frequency was 55.5% (5 seropositive calves/9 seropositive cows). Horizontal transmission was 22.7% (5 female calves seroconverted at least one time/22 females calves sampled during 24 months) and these 5 female calves had low avidity. In heifers, both seroprevalence and abortion rates decreased from 22.1 and 8.4% of 475 in 2009 to 6.1 and 4.3% of 578 in 2015, respectively (p < 0.01). Over 5 years, N. caninum-seroprevalence and the related abortions in heifers decreased after the control strategy was assessed.
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Affiliation(s)
| | - Agustín Scioli
- Private Veterinary Practitioner, Venado Tuerto, Argentina
| | - Alejandro Rodríguez
- Animal Production Department, National Institute of Agrarian de Technology, Balcarce, Argentina
| | - Joaquín Armendano
- Faculty of Agricultural Sciences, National University of Mar del Plata, Balcarce, Argentina
| | - Franco Fiorani
- Faculty of Agricultural Sciences, National University of Mar del Plata, Balcarce, Argentina.,National Research Council, Buenos Aires, Argentina
| | - Ángel Bence
- Faculty of Veterinary Sciences, National University of the Center of the Province of Buenos Aires, Tandil, Argentina
| | - Joaquín García
- Private Veterinary Practitioner, Venado Tuerto, Argentina
| | | | - Ignacio Gual
- Faculty of Agricultural Sciences, National University of Mar del Plata, Balcarce, Argentina
| | - Germán Cantón
- Animal Production Department, National Institute of Agrarian de Technology, Balcarce, Argentina
| | - Anselmo Odeón
- Faculty of Agricultural Sciences, National University of Mar del Plata, Balcarce, Argentina
| | - Carlos Campero
- Private Veterinary Practitioner, Venado Tuerto, Argentina
| | - Dadín Moore
- Animal Production Department, National Institute of Agrarian de Technology, Balcarce, Argentina.,National Research Council, Buenos Aires, Argentina
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Approaches for the vaccination and treatment of Neospora caninum infections in mice and ruminant models. Parasitology 2015; 143:245-59. [PMID: 26626124 DOI: 10.1017/s0031182015001596] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Neospora caninum is a leading cause of abortion in cattle, and is thus an important veterinary health problem of high economic significance. Vaccination has been considered a viable strategy to prevent bovine neosporosis. Different approaches have been investigated, and to date the most promising results have been achieved with live-attenuated vaccines. Subunit vaccines have also been studied, and most of them represented components that are functionally involved in (i) the physical interaction between the parasite and its host cell during invasion or (ii) tachyzoite-to-bradyzoite stage conversion. Drugs have been considered as an option to limit the effects of vertical transmission of N. caninum. Promising results with a small panel of compounds in small laboratory animal models indicate the potential value of a chemotherapeutical approach for the prevention of neosporosis in ruminants. For both, vaccines and drugs, the key for success in preventing vertical transmission lies in the application of bioactive compounds that limit parasite proliferation and dissemination, without endangering the developing fetus not only during an exogenous acute infection but also during recrudescence of a chronic infection. In this review, the current status of vaccine and drug development is presented and novel strategies against neosporosis are discussed.
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Müller J, Aguado-Martinez A, Manser V, Balmer V, Winzer P, Ritler D, Hostettler I, Arranz-Solís D, Ortega-Mora L, Hemphill A. Buparvaquone is active against Neospora caninum in vitro and in experimentally infected mice. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2015; 5:16-25. [PMID: 25941626 PMCID: PMC4412913 DOI: 10.1016/j.ijpddr.2015.02.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 01/29/2015] [Accepted: 02/04/2015] [Indexed: 11/16/2022]
Abstract
Buparvaquone inhibits proliferation of Neospora caninum at nanomolar concentrations. In vitro, the drug acts mainly parasitostatic. Parasiticidal effects occur at µmolar concentrations after extended periods of time. Buparvaquone acts slowly as evidenced by transmission electron microscopy. Buparvaquone prevents clinical signs of acute neosporosis in mice.
The naphthoquinone buparvaquone is currently the only drug used against theileriosis. Here, the effects of buparvaquone were investigated in vitro and in an experimental mouse model for Neospora caninum infection. In 4-day proliferation assays, buparvaquone efficiently inhibited N. caninum tachyzoite replication (IC50 = 4.9 nM; IC100 = 100 nM). However, in the long term tachyzoites adapted and resumed proliferation in the presence of 100 nM buparvaquone after 20 days of cultivation. Parasiticidal activity was noted after 9 days of culture in 0.5 µM or 6 days in 1 µM buparvaquone. TEM of N. caninum infected fibroblasts treated with 1 µM buparvaquone showed that the drug acted rather slowly, and ultrastructural changes were evident only after 3–5 days of treatment, including severe alterations in the parasite cytoplasm, changes in the composition of the parasitophorous vacuole matrix and a diminished integrity of the vacuole membrane. Treatment of N. caninum infected mice with buparvaquone (100 mg/kg) either by intraperitoneal injection or gavage prevented neosporosis symptoms in 4 out of 6 mice in the intraperitoneally treated group, and in 6 out of 7 mice in the group receiving oral treatment. In the corresponding controls, all 6 mice injected intraperitoneally with corn oil alone died of acute neosporosis, and 4 out of 6 mice died in the orally treated control group. Assessment of infection intensities in the treatment groups showed that, compared to the drug treated groups, the controls showed a significantly higher parasite load in the lungs while cerebral parasite load was higher in the buparvaquone-treated groups. Thus, although buparvaquone did not eliminate the parasites infecting the CNS, the drug represents an interesting lead with the potential to eliminate, or at least diminish, fetal infection during pregnancy.
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Affiliation(s)
- Joachim Müller
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
| | - Adriana Aguado-Martinez
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
| | - Vera Manser
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
| | - Vreni Balmer
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
| | - Pablo Winzer
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
| | - Dominic Ritler
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
| | - Isabel Hostettler
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
| | - David Arranz-Solís
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain
| | - Luis Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, Bern 3012, Switzerland
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Strohbusch M, Müller N, Hemphill A, Krebber R, Greif G, Gottstein B. Toltrazuril treatment of congenitally acquired Neospora caninum infection in newborn mice. Parasitol Res 2009; 104:1335-43. [DOI: 10.1007/s00436-009-1328-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 01/05/2009] [Indexed: 10/21/2022]
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