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Efficient Gene Knockout and Knockdown Systems in Neospora caninum Enable Rapid Discovery and Functional Assessment of Novel Proteins. mSphere 2022; 7:e0089621. [PMID: 35019667 PMCID: PMC8754167 DOI: 10.1128/msphere.00896-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The development of molecular genetics has greatly enhanced the study of the biology and pathology associated with parasites of the phylum Apicomplexa. While the molecular tools are highly developed for the apicomplexan Toxoplasma gondii, the closely related parasite Neospora caninum lacks efficient tools for genetic manipulation. To enable efficient homologous recombination in N. caninum, we targeted the Ku heterodimer DNA repair mechanism in the genomic reference strain, Nc-Liverpool (NcLiv), and show that deletion of Ku80 results in a destabilization and loss of its partner Ku70. Disruption of Ku80 generated parasites in which genes are efficiently epitope tagged and only short homology regions are required for gene knockouts. We used this improved strain to target novel nonessential genes encoding dense granule proteins that are unique to N. caninum or conserved in T. gondii. To expand the utility of this strain for essential genes, we developed the auxin-inducible degron system for N. caninum using parasite-specific promoters. As a proof of concept, we knocked down a novel nuclear factor in both N. caninum and T. gondii and showed that it is essential for survival of both parasites. Together, these efficient knockout and knockdown technologies will enable the field to unravel specific gene functions in N. caninum, which is likely to aid in the identification of targets responsible for the phenotypic differences observed between these two closely related apicomplexan parasites. IMPORTANCENeospora caninum is a parasite with veterinary relevance, inducing severe disease in dogs and reproductive disorders in ruminants, especially cattle, leading to major losses. The close phylogenetic relationship to Toxoplasma gondii and the lack of pathogenicity in humans drives an interest of the scientific community toward using N. caninum as a model to study the pathogenicity of T. gondii. To enable this comparison, it is important to develop efficient molecular tools for N. caninum, to gain accuracy and save time in genetic manipulation protocols. Here, we have developed base strains and protocols using the genomic reference strain of N. caninum to enable efficient knockout and knockdown assays in this model. We demonstrate that these tools are effective in targeting known and previously unexplored genes. Thus, these tools will greatly improve the study of this protozoan, as well as enhance its ability to serve as a model to understand other apicomplexan parasites.
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Chimeric Protein Designed by Genome-Scale Immunoinformatics Enhances Serodiagnosis of Bovine Neosporosis. J Clin Microbiol 2020; 58:JCM.01343-19. [PMID: 32404479 DOI: 10.1128/jcm.01343-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 05/05/2020] [Indexed: 01/15/2023] Open
Abstract
Neosporosis has become a concern since it is associated with abortion in cattle. Currently, in situ diagnosis is determined through anamnesis, evaluation of the history, and perception of the clinical signs of the herd. There is no practical and noninvasive test adapted to a large number of samples, which represents a gap for the use of new approaches that provide information about infections and the risks of herds. Here, we performed a search in the Neospora caninum genome by linear B-cell epitopes using immunoinformatic tools aiming to develop a chimeric protein with high potential to bind specifically to antibodies from infected cattle samples. An enzyme-linked immunosorbent assay with the new chimeric antigen was developed and tested with sera from natural field N. caninum-infected bovines. The cross-reactivity of the new antigen was also evaluated using sera from bovines infected by other abortive pathogens, including Trypanosoma vivax, Leptospira sp., Mycobacterium bovis, and Brucella abortus, and enzootic bovine leucosis caused by bovine leukemia virus, as well as with samples of animals infected with Toxoplasma gondii The assay using the chimeric protein showed 96.6% ± 3.4% of sensitivity in comparison to healthy animal sera. Meanwhile, in relation to false-positive results provided by cross-reactivity with others pathogens, the specificity value was 97.0% ± 2.9%. In conclusion, immunoinformatic tools provide an efficient platform to build an accurate protein to diagnose bovine neosporosis based on serum samples.
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Pagmadulam B, Myagmarsuren P, Fereig RM, Igarashi M, Yokoyama N, Battsetseg B, Nishikawa Y. Seroprevalence of Toxoplasma gondii and Neospora caninum infections in cattle in Mongolia. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 14:11-17. [PMID: 31014714 DOI: 10.1016/j.vprsr.2018.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 07/11/2018] [Accepted: 08/13/2018] [Indexed: 11/20/2022]
Abstract
Toxoplasma gondii and Neospora caninum are protozoan parasites that cause huge economic losses in animal industries worldwide. N. caninum can cause abortion storms and high culling rates in cattle, whereas T. gondii infection is a significant concern in both human and animals because it can induce abortion and clinical symptoms in immunocompromised hosts. The aim of this study was to determine the seroprevalence of T. gondii and N. caninum in cattle in Mongolia. Specific antibodies to T. gondii and N. caninum were detected by using an indirect enzyme-linked immunosorbent assay (iELISA) based on recombinant antigens of dense granule protein 7 of Toxoplasma gondii and surface antigen 1 of Neospora caninum, respectively. A total of 1438 cattle sera from 20 of 21 provinces of Mongolia and the capital city of Ulaanbaatar were tested. Overall, 18.7% and 26.2% of cattle were positive for specific antibodies to T. gondii and N. caninum, respectively. Prevalence rates were higher (T. gondii infection: P < .0001, N. caninum infection: P = .002) in the central region of Mongolia (T. gondii infection: 27.1%, N. caninum infection: 30.8%) compared with western region, suggesting that prevalence rates might be influenced by geographical condition, particularly warmer temperatures around this area in Mongolia. The lowest prevalence rates were observed in the western region of Mongolia (T. gondii: 9%, N. caninum: 20.8%). In addition, the seroprevalence of N. caninum in female animals (27.5%) was significantly higher than that in male animals (20.4%) (P = .018), suggesting an important risk factor of abortion and stillbirth in cattle. The present results showed that T. gondii and N. caninum infections might be a risk for public health and economy of the livestock industry in Mongolia. In conclusion, this study demonstrates high seroprevalences of T. gondii and N. caninum in Mongolia and provides valuable new data for development of control measures against these infections in Mongolia.
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Affiliation(s)
- Baldorj Pagmadulam
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Punsantsogvoo Myagmarsuren
- Institute of Veterinary Medicine, Laboratory of Molecular Genetics, Mongolian University of Life Sciences, Zaisan 17024, Ulaanbaatar, Mongolia
| | - Ragab M Fereig
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan; Department of Animal Medicine, Faculty of Veterinary Medicine, South Valley University, Qena 83523, Egypt
| | - Makoto Igarashi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Badgar Battsetseg
- Institute of Veterinary Medicine, Laboratory of Molecular Genetics, Mongolian University of Life Sciences, Zaisan 17024, Ulaanbaatar, Mongolia
| | - 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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Masatani T, Fereig RM, Otomaru K, Ishikawa S, Kojima I, Hobo S, Nishikawa Y. Seroprevalence of Cryptosporidium parvum and Neospora caninum in cattle in the southern Kyushu region of Japan. Parasitol Int 2018; 67:763-767. [PMID: 30110654 DOI: 10.1016/j.parint.2018.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 07/04/2018] [Accepted: 08/10/2018] [Indexed: 11/16/2022]
Abstract
Cryptosporidium parvum and Neospora caninum are common parasites in domesticated cattle worldwide, including in Japan. We carried out a serological survey to detect C. parvum and N. caninum infection among cattle in the southern Kyushu region of Japan-including the small islands-by indirect enzyme-linked immunosorbent assay based on recombinant antigens. We found that total seropositivity in 570 Japanese black cattle was 96.3% for C. parvum and 18.4% for N. caninum. Although seroprevalence was correlated with cattle age, differences in the seroprevalence of C. parvum among age groups were not statistically significant. On the other hand, N. caninum seroprevalence increased with age, suggesting horizontal transmission through ingestion of food or water contaminated with oocysts. These findings underscore the importance of monitoring C. parvum and N. caninum in cattle and implementing measures to prevent the spread of infection to other livestock and to humans.
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Affiliation(s)
- Tatsunori Masatani
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima, Japan.
| | - Ragab M Fereig
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, Japan; Department of Animal Medicine, Faculty of Veterinary Medicine, South Valley University, Qena City, Qena, Egypt
| | - Konosuke Otomaru
- Veterinary Teaching Hospital, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima, Japan
| | - Shingo Ishikawa
- Laboratory of Domestic Animal Internal Medicine, Kagoshima University, Korimoto, Kagoshima, Japan
| | - Isshu Kojima
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima, Japan
| | - Seiji Hobo
- Laboratory of Domestic Animal Internal Medicine, Kagoshima University, Korimoto, Kagoshima, Japan
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, Japan
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Uesaka K, Koyama K, Horiuchi N, Kobayashi Y, Nishikawa Y, Inokuma H. A clinical case of neosporosis in a 4-week-old holstein friesian calf which developed hindlimb paresis postnatally. J Vet Med Sci 2017; 80:280-283. [PMID: 29237996 PMCID: PMC5836764 DOI: 10.1292/jvms.17-0205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
A 4-week-old female Holstein Friesian calf presented with hindlimb paresis. Neurologic
examination of spinal reflexes revealed depressed or absent reflexes of the hindlimbs.
Menace responses on both sides disappeared on examination of cranial nerves. The calf was
finally diagnosed with Neospora caninum infection by pathological
findings including nonsuppurative inflammation associated with cysts in the cerebrum and
spinal cord. High levels of antibody against recombinant surface antigen 1 of N.
caninum (NcSAG1) were detected by ELISA from both serum and cerebrospinal fluid
(CSF) samples. This result suggests that detection of antibodies against N.
caninum by NcSAG1-ELISA in serum and CSF could be useful for the clinical
diagnosis of neosporosis in calves with acquired neurological signs.
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Affiliation(s)
- Karin Uesaka
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.,United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
| | - Kenji Koyama
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.,United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
| | - Noriyuki Horiuchi
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Yoshiyasu Kobayashi
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.,United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Hisashi Inokuma
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.,United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
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Sinnott FA, Monte LG, Collares TF, Silveira RM, Borsuk S. Review on the immunological and molecular diagnosis of neosporosis (years 2011–2016). Vet Parasitol 2017; 239:19-25. [DOI: 10.1016/j.vetpar.2017.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 03/31/2017] [Accepted: 04/05/2017] [Indexed: 11/25/2022]
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Importance of serological cross-reactivity among Toxoplasma gondii, Hammondia spp., Neospora spp., Sarcocystis spp. and Besnoitia besnoiti. Parasitology 2017; 144:851-868. [PMID: 28241894 PMCID: PMC5471829 DOI: 10.1017/s0031182017000063] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Toxoplasma gondii, Neospora spp., Sarcocystis spp., Hammondia spp. and Besnoitia besnoiti are genetically related cyst-forming coccidia. Serology is frequently used for the identification of T. gondii, Neospora spp. and B. besnoiti-exposed individuals. Serologic cross-reactions occur in different tests among animals infected with T. gondii and H. hammondi, as well as among animals infected by T. gondii and N. caninum. Infections caused by N. caninum and N. hughesi are almost indistinguishable by serology. Neospora caninum, B. besnoiti and Sarcocystis spp. infections in cattle show some degree of serologic cross-reactivity. Antibody cross-reactivity between Neospora spp. and H. heydorni-infected animals is suspected, but not proven to occur. We review serologic cross-reactivity among animals and/or humans infected with T. gondii, Neospora spp., Sarcocystis spp., Hammondia spp. and B. besnoiti. Emphasis is laid upon antigens and serological methods for N. caninum diagnosis which were tested for cross-reactivity with related protozoa. Species-specific antigens, as well as stage-specific proteins have been identified in some of these parasites and have promising use for diagnosis and epidemiological surveys.
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Jin C, Yu L, Wang Y, Hu S, Zhang S. Evaluation of Neospora caninum truncated dense granule protein 2 for serodiagnosis by enzyme-linked immunosorbent assay in dogs. Exp Parasitol 2015; 157:88-91. [PMID: 26172405 DOI: 10.1016/j.exppara.2015.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 05/20/2015] [Accepted: 07/08/2015] [Indexed: 11/24/2022]
Abstract
Neosporosis is an infectious disease caused by Neospora caninum, and it primarily affects cattle and dogs. An infection by N. caninum causes fetal abortion and neonatal mortality. Previous proteomics and immunoscreening analyses revealed that N. caninum dense granule antigen 2 (NcGRA2) has potential for serodiagnosis of N. caninum. Consequently, we expressed the truncated NcGRA2 (NcGRA2t), which lacks a signal peptide. We compared the serodiagnostic performances of recombinant NcGRA2t with that of truncated surface antigen 1 of N. caninum (NcSAG1t). Specificity testing using sera from mice infected with Toxoplasma gondii indicated that the NcGRA2t recombinant protein does not cross-react with T. gondii. In addition, we detected anti-NcGRA2t antibody at the acute stage in experimentally infected dogs, while detecting anti-NcSAG1t antibody during both the acute and chronic stages. Our results suggest that the levels of anti-NcGRA2 antibody reflect parasite activation in dogs. In conclusion, antibodies against NcGRA2t and NcSAG1t are suitable indicators to distinguish the acute and chronic stages of N. caninum infection.
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Affiliation(s)
- Chunmei Jin
- Department of Veterinary Medicine, Yanbian University, Yanji, Jilin Province 133002, China
| | - Longzheng Yu
- Department of Veterinary Medicine, Yanbian University, Yanji, Jilin Province 133002, China
| | - Yinan Wang
- Department of Veterinary Medicine, Yanbian University, Yanji, Jilin Province 133002, China
| | - Shiyue Hu
- Department of Veterinary Medicine, Yanbian University, Yanji, Jilin Province 133002, China
| | - Shoufa Zhang
- Department of Veterinary Medicine, Yanbian University, Yanji, Jilin Province 133002, China.
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Almería S, López-Gatius F. Markers related to the diagnosis and to the risk of abortion in bovine neosporosis. Res Vet Sci 2015; 100:169-75. [PMID: 25841793 DOI: 10.1016/j.rvsc.2015.03.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/14/2015] [Indexed: 01/01/2023]
Abstract
Bovine neosporosis has emerged as a main cause of abortion in cattle worldwide. An important question to understand the disease is why not all infected cows abort. In the present review we summarize the knowledge on markers related to the diagnosis and more importantly to the risk of abortion in the infected cow. Markers considered herein include those based on specific antibodies, antibody titers and antibody subtypes, cellular immunological markers, hormones and other proteins related to gestation. The identification of parasite molecules that are specifically identified in the aborting cows might help to understand the mechanism of parasite-associated abortion and control the disease.
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Affiliation(s)
- Sonia Almería
- Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), 08193 Barcelona, Spain; Centre de Recerca en Sanitat Animal (CReSA) - Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, 08193 Barcelona, Spain.
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Sinnott FA, Monte LG, Collares TF, De Matos BM, Pacheco DB, Borsuk S, Andreotti R, Hartleben CP. Blocking ELISA using recombinant NcSRS2 protein for diagnosing bovine neosporosis. Curr Microbiol 2014; 70:429-32. [PMID: 25432863 DOI: 10.1007/s00284-014-0737-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 10/15/2014] [Indexed: 10/24/2022]
Abstract
Neospora caninum is the etiologic agent of neosporosis, which leads to economic impacts on cattle industry. The reference method for serodiagnosis of neosporosis is the indirect fluorescent antibody test (IFAT). However, IFAT is laborious, expensive, and is not practicable in high throughput screening. In order to facilitate the serological diagnosis of neosporosis, we developed a blocking enzyme-linked immunosorbent assay (b-ELISA) based on NcSRS2 recombinant protein (rNcSRS2) and polyclonal antibodies against rNcSRS2 (b-ELISA/rNcSRS2). Compared to IFAT, b-ELISA/rNcSRS2 showed 93.7 % accuracy (98.7 % sensitivity and 88.7 % specificity), suggesting its potential as diagnostic assay to detect N. caninum antibodies in cattle sera.
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Affiliation(s)
- Francine A Sinnott
- Laboratório de Imunodiagnóstico, Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, CEP 96010-900, Pelotas, RS, P.O. Box 354, Brazil
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