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Mendoza FJ, Pérez-Écija A, Kappmeyer LS, Suarez CE, Bastos RG. New insights in the diagnosis and treatment of equine piroplasmosis: pitfalls, idiosyncrasies, and myths. Front Vet Sci 2024; 11:1459989. [PMID: 39205808 PMCID: PMC11349644 DOI: 10.3389/fvets.2024.1459989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Accepted: 07/29/2024] [Indexed: 09/04/2024] Open
Abstract
Equine piroplasmosis (EP) is a global tick-borne disease of equids caused by the intraerythrocytic apicomplexan parasites Theileria equi and Babesia caballi, and the more recently discovered Theileria haneyi. These parasites can be transmitted by several tick species, including Dermacentor, Hyalomma, and Rhipicephalus, but iatrogenic and vertical transmission are also common. Clinical signs of EP include poor performance, fever, icterus, abortions, among others, and peracute or acute forms of infection are associated with high mortality in non-endemic areas. EP is a reportable disease and represents an important barrier for the international trade of horses and other equids, causing disruption of international equine sports. Tick control measures, serological and molecular diagnostic methods, and parasiticidal drugs are currently used against EP, while vaccines remain unavailable. Since most acaricides used in equids are non-environmentally friendly and linked to drug resistances, this is considered as an unsustainable approach. Imidocarb dipropionate (ID) and buparvaquone (BPQ) are currently the main drugs used to control the disease. However, while ID has several side and toxic effects and recurrent failures of treatment have been reported, BPQ is less effective in the clearance of T. equi infection and not available in some countries. Thus, novel alternative and effective therapeutics are needed. While current trade regulations require testing equids for EP before exportation, the lack of standardized PCR tests and limitations of the currently recommended serological assays entail a risk of inaccurate diagnosis. Hereby, we propose a combination of standardized PCR-based techniques and improved serological tests to diminish the risks of exporting EP-infected animals making equid international trade safer. In addition, this review discusses, based on scientific evidence, several idiosyncrasies, pitfalls and myths associated with EP, and identifies weaknesses of current methods of control and gaps of research, as initial steps toward developing novel strategies leading to control this disease.
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Affiliation(s)
- Francisco J. Mendoza
- Department of Animal Medicine and Surgery, College of Veterinary Medicine, University of Cordoba, Cordoba, Spain
| | - Alejandro Pérez-Écija
- Department of Animal Medicine and Surgery, College of Veterinary Medicine, University of Cordoba, Cordoba, Spain
| | - Lowell S. Kappmeyer
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture (USDA), Pullman, WA, United States
| | - Carlos E. Suarez
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture (USDA), Pullman, WA, United States
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Reginaldo G. Bastos
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture (USDA), Pullman, WA, United States
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
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Zhou B, Yang G, Hu Z, Chen K, Guo W, Wang X, Du C. Development of a Real-Time Quantitative PCR Based on a TaqMan-MGB Probe for the Rapid Detection of Theileria haneyi. Microorganisms 2023; 11:2633. [PMID: 38004645 PMCID: PMC10673206 DOI: 10.3390/microorganisms11112633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/20/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023] Open
Abstract
Equine piroplasmosis (EP) is a parasitic disease caused by Theileria equi (T. equi), Babesia caballi (B. caballi) and Theileria haneyi (T. haneyi). This disease is considered to be reportable by the World Organization for Animal Health (WOAH). Real-time quantitative PCR (qPCR) is regarded as a straightforward, rapid and sensitive diagnostic method to detect pathogens. However, qPCR has not been employed in the various epidemiological investigations of T. haneyi. In this study, we developed a new qPCR method to detect T. haneyi based on the chr1sco (chromosome 1 single-copy open reading frame (ORF)) gene, which has no detectable orthologs in T. equi or B. caballi. A TaqMan MGB probe was used in the development of the qPCR assay. A plasmid containing the chr1sco gene was constructed and used to establish the standard curves. The novel qPCR technique demonstrated great specificity for detecting additional frequent equine infectious pathogens and sensitivity for detecting diluted standard plasmids. This qPCR was further validated by comparison with an optimized nested PCR (nPCR) assay in the analysis of 96 clinical samples. The agreement between the nPCR assay and the established qPCR assay was 85.42%. The newly established method could contribute to the accurate diagnosis of T. haneyi infections in horses.
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Affiliation(s)
| | | | | | | | | | - Xiaojun Wang
- State Key Laboratory of Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (B.Z.); (G.Y.); (Z.H.); (K.C.); (W.G.)
| | - Cheng Du
- State Key Laboratory of Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (B.Z.); (G.Y.); (Z.H.); (K.C.); (W.G.)
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Moudgil P, Grakh K, Kumar R, Sharma M, Gupta R, Jindal N. First Molecular Confirmed Outbreak of Malignant Ovine Theileriosis in Sheep from North India. Acta Parasitol 2023; 68:527-534. [PMID: 37328625 DOI: 10.1007/s11686-023-00684-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 05/08/2023] [Indexed: 06/18/2023]
Abstract
CONTEXT Malignant ovine theileriosis is a tick-borne disease of sheep and goats, caused by protozoan Theileria lestoquardi. The disease has serious economic implications for small ruminant production around the world. METHODS An outbreak of malignant ovine theileriosis in a sheep flock was investigated from Hisar district of Haryana, India, in March 2022. The etiological agent was identified using polymerase chain reaction assay with genus specific primers targeting 18S rRNA gene and subsequently confirmed by sequencing. RESULTS The morbidity, mortality and case fatality rate reported in the outbreak were 22.2, 18.8 and 85%, respectively. The phylogenetic analysis clustered the present study T. lestoquardi isolate in the same clade with T. lestoquardi from Iraq, Iran and Pakistan with maximum nucleotide identity of 99.37% with strains from Iraq. The tick vector Hyalomma anatolicum recovered from dead animals was implicated in the disease's transmission. CONCLUSIONS Malignant ovine theileriosis resulted in high case fatality rate. This study presents the first molecularly confirmed outbreak of malignant ovine theileriosis outbreak in the North Indian region, with characteristic post-mortem findings.
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Affiliation(s)
- Pallavi Moudgil
- Department of Veterinary Public Health and Epidemiology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125004, India
| | - Kushal Grakh
- Department of Veterinary Public Health and Epidemiology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125004, India
| | - Ramesh Kumar
- Department of Veterinary Public Health and Epidemiology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125004, India.
| | - Maneesh Sharma
- Department of Veterinary Clinical Complex, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125004, India
| | - Renu Gupta
- Department of Veterinary Public Health and Epidemiology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125004, India
| | - Naresh Jindal
- Department of Veterinary Public Health and Epidemiology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125004, India
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Wang BH, Du LF, Zhang MZ, Xia LY, Li C, Lin ZT, Wang N, Gao WY, Ye RZ, Liu JY, Han XY, Shi WQ, Shi XY, Jiang JF, Jia N, Cui XM, Zhao L, Cao WC. Genomic Characterization of Theileria luwenshuni Strain Cheeloo. Microbiol Spectr 2023; 11:e0030123. [PMID: 37260375 PMCID: PMC10434005 DOI: 10.1128/spectrum.00301-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023] Open
Abstract
Theileria, a tick-borne intracellular protozoan, can cause infections of various livestock and wildlife around the world, posing a threat to veterinary health. Although more and more Theileria species have been identified, genomes have been available only from four Theileria species to date. Here, we assembled a whole genome of Theileria luwenshuni, an emerging Theileria, through next-generation sequencing of purified erythrocytes from the blood of a naturally infected goat. We designated it T. luwenshuni str. Cheeloo because its genome was assembled by the researchers at Cheeloo College of Medicine, Shandong University, China. The genome of T. lunwenshuni str. Cheeloo was the smallest in comparison with the other four Theileria species. T. luwenshuni str. Cheeloo possessed the fewest gene gains and gene family expansion. The protein count of each category was always comparable between T. luwenshuni str. Cheeloo and T. orientalis str. Shintoku in the Eukaryote Orthologs annotation, though there were remarkable differences in genome size. T. luwenshuni str. Cheeloo had lower counts than the other four Theileria species in most categories at level 3 of Gene Ontology annotation. Kyoto Encyclopedia of Genes and Genomes annotation revealed a loss of the c-Myb in T. luwenshuni str. Cheeloo. The infection rate of T. luwenshuni str. Cheeloo was up to 81.5% in a total of 54 goats from three flocks. The phylogenetic analyses based on both 18S rRNA and cox1 genes indicated that T. luwenshuni had relatively low diversity. The first characterization of the T. luwenshuni genome will promote better understanding of the emerging Theileria. IMPORTANCE Theileria has led to substantial economic losses in animal husbandry. Whole-genome sequencing data of the genus Theileria are currently limited, which has prohibited us from further understanding their molecular features. This work depicted whole-genome sequences of T. luwenshuni str. Cheeloo, an emerging Theileria species, and reported a high prevalence of T. luwenshuni str. Cheeloo infection in goats. The first assembly and characterization of T. luwenshuni genome will benefit exploring the infective and pathogenic mechanisms of the emerging Theileria to provide scientific basis for future control strategies of theileriosis.
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Affiliation(s)
- Bai-Hui Wang
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Li-Feng Du
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Ming-Zhu Zhang
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Luo-Yuan Xia
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Cheng Li
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Zhe-Tao Lin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Ning Wang
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Wan-Ying Gao
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Run-Ze Ye
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Jin-Yue Liu
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Xiao-Yu Han
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Wen-Qiang Shi
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Xiao-Yu Shi
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Jia-Fu Jiang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Na Jia
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Xiao-Ming Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Lin Zhao
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Wu-Chun Cao
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
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Wondim M, Dunaj-Małyszko J, Okrzeja J, Majewski P, Czupryna P, Pancewicz S, Moniuszko-Malinowska A. Detection of Babesia and Theileria species in ticks from North-Eastern Poland. J Travel Med 2023; 30:taad071. [PMID: 37220879 PMCID: PMC10289509 DOI: 10.1093/jtm/taad071] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/24/2023] [Accepted: 05/03/2023] [Indexed: 05/25/2023]
Affiliation(s)
- Mulugeta Wondim
- Department of Infectious Diseases and Neuroinfections, Medical University of Bialystok, Żurawia 14/ block E, 15-540 Bialystok, Poland
| | - Justyna Dunaj-Małyszko
- Department of Infectious Diseases and Neuroinfections, Medical University of Bialystok, Żurawia 14/ block E, 15-540 Bialystok, Poland
| | - Jakub Okrzeja
- Medical University of Bialystok, Jana Kilińskiego 1, 15-089 Białystok, Poland
| | - Piotr Majewski
- Department of Microbiology, Medical University of Bialystok, Waszyngtona 15a, 15-269 Bialystok, Poland
| | - Piotr Czupryna
- Department of Infectious Diseases and Neuroinfections, Medical University of Bialystok, Żurawia 14/ block E, 15-540 Bialystok, Poland
| | - Sławomir Pancewicz
- Department of Infectious Diseases and Neuroinfections, Medical University of Bialystok, Żurawia 14/ block E, 15-540 Bialystok, Poland
| | - Anna Moniuszko-Malinowska
- Department of Infectious Diseases and Neuroinfections, Medical University of Bialystok, Żurawia 14/ block E, 15-540 Bialystok, Poland
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Zhang Y, Shi Q, Laven R, Li C, He W, Zheng H, Liu S, Lu M, Yang DA, Guo Q, Chahan B. Prevalence and genetic diversity of Theileria equi from horses in Xinjiang Uygur Autonomous region, China. Ticks Tick Borne Dis 2023; 14:102193. [PMID: 37150103 DOI: 10.1016/j.ttbdis.2023.102193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 04/19/2023] [Accepted: 04/23/2023] [Indexed: 05/09/2023]
Abstract
Theileria equi is a tick-borne intracellular apicomplexan protozoan parasite that causes equine theileriosis (ET). ET is an economically important disease with a worldwide distribution that significantly impacts international horse movement. Horses are an essential part of the economy in Xinjiang which is home to ∼10% of all the horses in China. However, there is very limited information on the prevalence and genetic complexity of T. equi in this region. Blood samples from 302 horses were collected from May to September 2021 in Ili, Xinjiang, and subjected to PCR examination for the presence of T. equi. In addition, a Bayesian latent class model was employed to estimate the true prevalence of T. equi, and a phylogenetic analysis was carried out based on the 18S rRNA gene of T. equi isolates. Seventy-two horses (23.8%) were PCR positive. After accounting for the imperfect PCR test using a Bayesian latent class model, the estimated true prevalence differed considerably between age groups, being 10.8% (95%CrI: 5.8% - 17.9%) in ≤ 3-year-old horses and 35.7% (95%CrI: 28.1% - 44.5%) in horses that were > 3 year-old. All T. equi isolates had their 18S rRNA gene (430bp) sequenced and analyzed in order to identify whether there were multiple genotypes of T. equi in the Xinjiang horse population. All of the 18S rRNA genes clustered into one phylogenetic group, clade E, which is thus probably the dominant genotype of T. equi in Xinjiang, China. To summarize, we monitored the prevalence of T. equi in horses of Xinjiang, China, with a focus on the association between age and the occurrence of T. equi by Bayesian modelling, accompanied by the genotyping of T. equi isolates. Obtaining the information on genotypes and age structure is significant in monitoring the spread of T. equi and studying the factors responsible for the distribution.
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Affiliation(s)
- Yang Zhang
- Laboratory of Parasitology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China.
| | - Qianyun Shi
- Laboratory of Parasitology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China
| | - Richard Laven
- School of Veterinary Science, Massey University, Palmerston North 4474, New Zealand
| | - Caishan Li
- Laboratory of Parasitology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China
| | - Wenwen He
- Laboratory of Parasitology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China
| | - Huizhen Zheng
- Laboratory of Parasitology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China
| | - Shifang Liu
- Yunnan Branch, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences&Peking Union Medical College, Jinghong, Yunnan 661000, China
| | - Mingmin Lu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
| | - Danchen Aaron Yang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
| | - Qingyong Guo
- Laboratory of Parasitology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China
| | - Bayin Chahan
- Laboratory of Parasitology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China
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Onzere CK, Hulbert M, Sears KP, Williams LBA, Fry LM. Tulathromycin and Diclazuril Lack Efficacy against Theileria haneyi, but Tulathromycin Is Not Associated with Adverse Clinical Effects in Six Treated Adult Horses. Pathogens 2023; 12:pathogens12030453. [PMID: 36986375 PMCID: PMC10055745 DOI: 10.3390/pathogens12030453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 02/28/2023] [Accepted: 03/10/2023] [Indexed: 03/16/2023] Open
Abstract
Equine theileriosis, caused by Theileria haneyi and Theileria equi, leads to anemia, exercise intolerance, and occasionally, death. Theileriosis-free countries prohibit the importation of infected horses, resulting in significant costs for the equine industry. Imidocarb dipropionate is the only treatment for T. equi in the United States, but lacks efficacy against T. haneyi. The goal of this study was to assess the in vivo efficacy of tulathromycin and diclazuril against T. haneyi. Fourteen T. haneyi-infected horses were utilized. Six were treated with eight weekly 2.5 mg/kg doses of tulathromycin. Three were treated daily for eight weeks with 2.5 mg/kg diclazuril. Three were pre-treated with 0.5 mg/kg diclazuril daily for one month to determine whether low-dose diclazuril prevents infection. Following infection, the dose was increased to 2.5 mg/kg for eight weeks. Two infected horses remained untreated as controls. The horses were assessed via nested PCR, physical exams, complete blood counts, serum chemistry panels, and cytology. Tulathromycin and diclazuril failed to clear T. haneyi and the treated and control groups exhibited similar parasitemia and packed cell volume declines. To obtain additional safety data on tulathromycin use in adult horses, necropsy and histopathology were performed on tulathromycin-treated horses. No significant lesions were detected.
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Affiliation(s)
- Cynthia K. Onzere
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA
| | - Morgan Hulbert
- College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Kelly P. Sears
- Department of Clinical Science, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
| | - Laura B. A. Williams
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA
| | - Lindsay M. Fry
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA
- Animal Disease Research Unit, USDA-ARS, Pullman, WA 99164, USA
- Correspondence:
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Coultous R, Gotić J, McCann M, Sutton D, Beck R, Shiels B. Novel equi merozoite antigen (ema-1) gene heterogeneity in a geographically isolated Theileria equi population in Croatia. Parasit Vectors 2022; 15:401. [PMID: 36316753 PMCID: PMC9623909 DOI: 10.1186/s13071-022-05484-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/09/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND The apicomplexan haemoparasite Theileria equi, a causative agent of equine piroplasmosis, is an established pathogen of significant welfare and economic concern within the Croatian equine population. A previous large surveillance study of T. equi has identified two distinct parasite populations, one in the north and one in the south, geographically separated by the Dinaric Alps, which traverse the country. This study aimed to further investigate the genetic diversity within these two populations, focussing on allelic variability of the equi merozoite antigen gene, ema-1. METHODS Following nested PCR of DNA isolates, the generated ema-1 amplicons were subsequently sequenced and compared by phylogenetic analysis to available sequences representing previously described ema-1 genotypes (groups A-C). RESULTS Isolates from the southern T. equi population clustered with the existing ema-1 groups A and B. Strikingly, isolates from the northern population clustered into two novel ema-1 genotypes, named groups D and E. CONCLUSIONS This detection of hitherto unreported genotypes suggests that historic geographical isolation has led to a degree of divergent evolution in this northern T. equi population. Additionally, current global regulatory testing of equine piroplasmosis relies heavily on EMA-1 based immunodiagnostics, and the discovery of unique ema-1 genotypes may question the efficacy of current diagnostics in international equine movement, with ramifications for the global equine community.
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Affiliation(s)
- Robert Coultous
- grid.8756.c0000 0001 2193 314XInstitute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Jelena Gotić
- grid.4808.40000 0001 0657 4636Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Martine McCann
- grid.8756.c0000 0001 2193 314XSchool of Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - David Sutton
- grid.8756.c0000 0001 2193 314XSchool of Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Relja Beck
- grid.417625.30000 0004 0367 0309Laboratory for Parasitology, Croatian Veterinary Institute, Zagreb, Croatia
| | - Brian Shiels
- grid.8756.c0000 0001 2193 314XInstitute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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Ahedor B, Kothalawala H, Kanagaratnam R, Vimalakumar SC, Otgonsuren D, Tuvshintulga B, Batmagnai E, Silva SSP, Sivakumar T, Yokoyama N. First detection of Theileria equi in free-roaming donkeys (Equus africanus asinus) in Sri Lanka. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 99:105244. [PMID: 35149223 DOI: 10.1016/j.meegid.2022.105244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/13/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Equine piroplasmosis (EP) is a tick-borne disease caused by Theileria equi and Babesia caballi in equids, including horses, donkeys, zebras, and mules. It is globally endemic with significant economic impact on the equine industry. Infected animals may serve as carriers, and they may be a source of infection for ticks, thereby posing a great challenge for disease management. Sri Lanka is a tropical country, where infections by various tick-borne parasites are common among livestock animals. However, infections by T. equi and B. caballi remain unstudied in Sri Lanka. Therefore, in the present study, we conducted an epidemiological survey to investigate the presence of T. equi and B. caballi in apparently healthy free-roaming donkeys. Blood samples were randomly taken from 111 donkeys in Mannar (n = 100) and Kilinochchi (n = 11) districts in Sri Lanka. Thin blood smears were prepared from the blood samples and subjected to microscopic examination. Additionally, blood DNA samples were prepared and screened for T. equi and B. caballi infections using species-specific PCR assays. Our results showed that 64 (57.7%) and 95 (85.6%) of the donkeys were positive for T. equi by microscopy and PCR, respectively. However, all samples were negative for B. caballi. Phylogenetic analysis of the T. equi 18S rRNA sequences detected two distinct genotypes, namely C and D. To our knowledge, this is the first report of T. equi in Sri Lanka and of genotype C in donkeys. The present study highlights the importance of monitoring the shrinking donkey population in Sri Lanka owing to EP caused by T. equi.
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Affiliation(s)
- Believe Ahedor
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan; Department of Animal Experimentation, Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana
| | | | | | | | - Davaajav Otgonsuren
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Bumduuren Tuvshintulga
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Enkhbaatar Batmagnai
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | | | - Thillaiampalam Sivakumar
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan; OIE Reference Laboratory for Equine Piroplasmosis, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
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10
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The Piroplasmida Babesia, Cytauxzoon, and Theileria in farm and companion animals: species compilation, molecular phylogeny, and evolutionary insights. Parasitol Res 2022; 121:1207-1245. [DOI: 10.1007/s00436-022-07424-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/02/2022] [Indexed: 12/13/2022]
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11
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The basis of molecular diagnostics for piroplasmids: Do the sequences lie? Ticks Tick Borne Dis 2022; 13:101907. [DOI: 10.1016/j.ttbdis.2022.101907] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 12/15/2022]
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12
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Elsawy BSM, Nassar AM, Alzan HF, Bhoora RV, Ozubek S, Mahmoud MS, Kandil OM, Mahdy OA. Rapid Detection of Equine Piroplasms Using Multiplex PCR and First Genetic Characterization of Theileria haneyi in Egypt. Pathogens 2021; 10:pathogens10111414. [PMID: 34832570 PMCID: PMC8620363 DOI: 10.3390/pathogens10111414] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/13/2023] Open
Abstract
Equine Piroplasmosis (EP) is an infectious disease caused by the hemoprotozoan parasites Theileria equi, Babesia caballi, and the recently identified species T. haneyi. Hereby, we used a multiplex PCR (mPCR) targeting the 18S rRNA gene of T. equi and B. caballi for the simultaneous detection of EP in Egyptian equids and examined the presence of T. haneyi infections in Egypt. Blood samples from 155 equids (79 horses and 76 donkeys) collected from different governorates of Egypt were examined by mPCR and PCR targeting T. hayeni. The mPCR method revealed a prevalence of T. equi of 20.3% in horses and of 13.1% in donkeys and a prevalence of B. caballi of 1.2% in horses. B. caballi was not detected in donkeys in the current study. The mPCR method also detected coinfections with both species (2.5% and 1.3% in horses and donkeys, respectively). Additionally, we report the presence of T. haneyi in Egypt for the first time in 53.1% of the horse and 38.1% of the donkey tested samples. Coinfection with T. haneyi and T. equi was found in 13.5% of the samples, while infection with the three EP species was found in 1.9% of the samples.
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Affiliation(s)
- Bassma S. M. Elsawy
- Parasitology and Animal Diseases Department, Veterinary Research Institute, National Research Centre, Dokki, Giza 12622, Egypt; (B.S.M.E.); (M.S.M.); (O.M.K.)
- Tick and Tick-Borne Diseases Research Unit, Veterinary Research Institute, National Research Centre, Dokki, Giza 12622, Egypt
| | - Ahmed M. Nassar
- Parasitology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12622, Egypt;
| | - Heba F. Alzan
- Parasitology and Animal Diseases Department, Veterinary Research Institute, National Research Centre, Dokki, Giza 12622, Egypt; (B.S.M.E.); (M.S.M.); (O.M.K.)
- Tick and Tick-Borne Diseases Research Unit, Veterinary Research Institute, National Research Centre, Dokki, Giza 12622, Egypt
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA;
- Correspondence: (H.F.A.); (O.A.M.); Tel.: +20-100-241-0507(O.A.M.)
| | - Raksha V. Bhoora
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa;
| | - Sezayi Ozubek
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA;
- Department of Parasitology, Faculty of Veterinary Medicine, University of Firat, Elazig 23119, Turkey
| | - Mona S. Mahmoud
- Parasitology and Animal Diseases Department, Veterinary Research Institute, National Research Centre, Dokki, Giza 12622, Egypt; (B.S.M.E.); (M.S.M.); (O.M.K.)
- Tick and Tick-Borne Diseases Research Unit, Veterinary Research Institute, National Research Centre, Dokki, Giza 12622, Egypt
| | - Omnia M. Kandil
- Parasitology and Animal Diseases Department, Veterinary Research Institute, National Research Centre, Dokki, Giza 12622, Egypt; (B.S.M.E.); (M.S.M.); (O.M.K.)
| | - Olfat A. Mahdy
- Parasitology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12622, Egypt;
- Correspondence: (H.F.A.); (O.A.M.); Tel.: +20-100-241-0507(O.A.M.)
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13
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Molecular detection and phylogenetic characterization of Theileria equi in horses (Equus caballus) from a peri-urban area of Argentina. Ticks Tick Borne Dis 2021; 12:101810. [PMID: 34416568 DOI: 10.1016/j.ttbdis.2021.101810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 07/16/2021] [Accepted: 07/26/2021] [Indexed: 11/21/2022]
Abstract
To investigate the presence of Theileria equi in an endemic area of equine piroplasmosis 42 horses (Equus caballus) from Corrientes City, Argentina were sampled. Eighty-one percent (34 blood samples) of the analyzed horses were tested positive to the presence of piroplasmid 18S rDNA. All these samples could be identified as T. equi by amplifying the specific EMA-1 (merozoite antigen 1) gene of this species. Phylogenetic analysis of an obtained 18S rDNA complete sequence from one strain resulted in the identification of this sample as T. equi sensu stricto (genotype A). This study presents the first molecular detection and characterization of T. equi by the complete 18S rDNA sequence in Argentina. Based on these results further studies should be carried out to investigate the distribution and heterogeneity of presented genotypes of T. equi in Argentina, which is essential for the diagnosis, prevention and treatment of equine piroplasmosis.
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14
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Idoko IS, Edeh RE, Adamu AM, Machunga-Mambula S, Okubanjo OO, Balogun EO, Adamu S, Johnson W, Kappmeyer L, Mousel M, Ueti MW. Molecular and Serological Detection of Piroplasms in Horses from Nigeria. Pathogens 2021; 10:pathogens10050508. [PMID: 33922468 PMCID: PMC8146079 DOI: 10.3390/pathogens10050508] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 11/16/2022] Open
Abstract
Equine piroplasmosis, an economically important disease of equids caused by the hemoprotozoan parasites Theileria equi, T. haneyi, and Babesia caballi, has a worldwide distribution. These parasites are transmitted by ixodid ticks. To improve the detection of horses in Nigeria exposed to piroplasm parasites, 72 horses with variable clinical signs of piroplasmosis were sampled from Northwest and Northcentral Nigeria and tested by nPCR and cELISA. Blood and serum samples were collected from each horse via jugular venesection. Individually, nPCR or cELISA failed to identify all horses exposed to piroplasms. A combination of species-specific nPCR and the OIE-approved T. equi and B. caballi cELISAs enhanced the detection of horses exposed to parasites. The results also demonstrated horses showing abnormal hematology were positive for only T. equi, except for one sample that was coinfected with T. equi and T. haneyi. We also identified ticks collected from some of the horses, with Rhipicephalus evertsi evertsi being the most prevalent. This study shows that a larger proportion of horses in the sample set were exposed to T. equi than B. caballi or T. haneyi. Additionally, ticks that have been previously reported as potential vectors for these parasites were found to have infested sampled horses. Further studies are needed to investigate which tick species are competent vectors for Theileria spp. and Babesia caballi in Nigeria.
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Affiliation(s)
- Idoko S. Idoko
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Abuja, Gwagwalada 902101, Nigeria;
| | - Richard E. Edeh
- Department of Veterinary Medicine, Surgery and Radiology, Faculty of Veterinary Medicine, University of Jos, Jos 930222, Nigeria;
| | - Andrew M. Adamu
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Abuja, Gwagwalada 902101, Nigeria;
| | | | - Oluyinka O. Okubanjo
- Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria 810107, Nigeria;
| | - Emmanuel O. Balogun
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Zaria 810107, Nigeria;
| | - Sani Adamu
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria 810107, Nigeria;
| | - Wendell Johnson
- Animal Disease Research Unit, USDA-ARS, Pullman, WA 99164-6630, USA; (W.J.); (L.K.); (M.M.)
| | - Lowell Kappmeyer
- Animal Disease Research Unit, USDA-ARS, Pullman, WA 99164-6630, USA; (W.J.); (L.K.); (M.M.)
| | - Michelle Mousel
- Animal Disease Research Unit, USDA-ARS, Pullman, WA 99164-6630, USA; (W.J.); (L.K.); (M.M.)
| | - Massaro W. Ueti
- Animal Disease Research Unit, USDA-ARS, Pullman, WA 99164-6630, USA; (W.J.); (L.K.); (M.M.)
- Department of Veterinary Microbiology & Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA
- Correspondence:
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15
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Development of an Indirect ELISA to Detect Equine Antibodies to Theileria haneyi. Pathogens 2021; 10:pathogens10030270. [PMID: 33673478 PMCID: PMC7997436 DOI: 10.3390/pathogens10030270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 11/17/2022] Open
Abstract
The apicomplexan parasite Theileria haneyi is one of two known causative agents of equine theileriosis. It causes milder clinical disease than its more virulent counterpart, Theileria equi, in experimentally infected horses, and can superinfect T. equi-positive horses. The current equi merozoite antigen 1 (EMA1)-based competitive enzyme-linked immunosorbent assay (ELISA)used in the U.S. to detect equine theileriosis detects T. equi but not T. haneyi, and the complexity of molecular assays precludes widespread use for epidemiologic studies. In order to facilitate urgently needed studies on the prevalence of T. haneyi, the goal of this study was to develop a sensitive and specific serologic assay for the diagnosis of T. haneyi based on the equi merozoite antigen 11 (ThEMA11). To achieve this objective, ThEMA11 was recombinantly expressed in eukaryotic cells and its antigenicity assessed using sera from T. haneyi-experimentally infected horses. Confirmation of sera reactivity enabled design and optimization of an indirect ELISA. Specificity of the ELISA for T. haneyi was assessed using a cohort of sera from horses experimentally infected and confirmed PCR-positive for either T. equi or T. haneyi. Data from field samples further demonstrate that the ThEMA11 ELISA is capable of identifying T. haneyi antibodies in horses from multiple continents around the world.
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16
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Romero-Salas D, Solis-Cortés M, Zazueta-Islas HM, Flores-Vásquez F, Cruz-Romero A, Aguilar-Domínguez M, Salguero-Romero JL, de León AP, Fernández-Figueroa EA, Lammoglia-Villagómez MÁ, Becker I, Sánchez-Montes S. Molecular detection of Theileria equi in horses from Veracruz, Mexico. Ticks Tick Borne Dis 2021; 12:101671. [PMID: 33545504 DOI: 10.1016/j.ttbdis.2021.101671] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/11/2021] [Accepted: 01/17/2021] [Indexed: 12/17/2022]
Abstract
Equine piroplasmosis is a tropical parasitic disease caused by several intraerythrocytic members of the genera Babesia and Theileria. These pathogens are transmitted by multiple tick species and are considered as important exotic microorganisms in several countries. Equine piroplasmosis causes significant economic losses due to abortions, decreased activity and even death of equines, making surveillance of these infectious disease essential. In the northern and eastern parts of Mexico, few molecular and serological reports have been made on the presence and exposure of horse to these agents. For this reason, the aim of the current work was to perform a molecular detection study of Babesia and Theileria in equines from the state of Veracruz, Mexico. A total of 100 whole blood samples were tested. Chelex-100 resin was used for DNA extraction and a fragment of 459 bp of the 18S rRNA gene of members of the genera Babesia/Theileria were identified. Of the 100 samples analysed, 18 tested positive for Babesia/Theileria, resulting in a prevalence of 18 %. Identity analyses and phylogenetic reconstruction revealed that all samples were infected with Theileria equi. This work represents the first molecular record of Babesia/Theileria in equines from the state of Veracruz, Mexico, and demonstrates the endemicity of T. equi in this region of the country.
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Affiliation(s)
- Dora Romero-Salas
- Laboratorio de Parasitología, Posta Zootécnica Torreón del Molino, Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Veracruz, Mexico
| | - Marlene Solis-Cortés
- Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Héctor M Zazueta-Islas
- Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Fernanda Flores-Vásquez
- Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Anabel Cruz-Romero
- Laboratorio de Parasitología, Posta Zootécnica Torreón del Molino, Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Veracruz, Mexico
| | - Mariel Aguilar-Domínguez
- Laboratorio de Parasitología, Posta Zootécnica Torreón del Molino, Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Veracruz, Mexico
| | - José Luis Salguero-Romero
- Laboratorio de Parasitología, Posta Zootécnica Torreón del Molino, Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Veracruz, Mexico
| | | | - Edith A Fernández-Figueroa
- Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico; Computational and Integrative Genomics, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico
| | | | - Ingeborg Becker
- Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Sokani Sánchez-Montes
- Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico; Facultad de Ciencias Biológicas y Agropecuarias, Universidad Veracruzana, Veracruz, Mexico.
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17
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Imidocarb Dipropionate Lacks Efficacy against Theileria haneyi and Fails to Consistently Clear Theileria equi in Horses Co-Infected with T. haneyi. Pathogens 2020; 9:pathogens9121035. [PMID: 33321715 PMCID: PMC7764667 DOI: 10.3390/pathogens9121035] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/05/2020] [Accepted: 12/08/2020] [Indexed: 12/27/2022] Open
Abstract
Control of Theileria equi, the primary cause of equine theileriosis, is largely reliant on acaracide use and chemosterilization with imidocarb dipropionate (ID). However, it is currently unknown if ID is effective against Theileria haneyi, the recently identified second causative agent of equine theileriosis, or if the drug maintains effectiveness against T. equi in the presence of T. haneyi co-infection. The purpose of this study was to address these questions using ID treatment of the following three groups of horses: (1) five T. haneyi infected horses; (2) three T. haneyi-T. equi infected horses; and (3) three T. equi-T. haneyi infected horses. Clearance was first evaluated using nPCR for each Theileria sp. on peripheral blood samples. ID failed to clear T. haneyi in all three groups of horses, and failed to clear T. equi in two of three horses in group two. For definitive confirmation of infection status, horses in groups two and three underwent splenectomy post-treatment. The T. equi-nPCR-positive horses in group two developed severe clinical signs and were euthanized. Remaining horses exhibited moderate signs consistent with T. haneyi. Our results demonstrate that ID therapy lacks efficacy against T. haneyi, and T. haneyi-T. equi co-infection may interfere with ID clearance of T. equi.
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Tirosh-Levy S, Gottlieb Y, Fry LM, Knowles DP, Steinman A. Twenty Years of Equine Piroplasmosis Research: Global Distribution, Molecular Diagnosis, and Phylogeny. Pathogens 2020; 9:E926. [PMID: 33171698 PMCID: PMC7695325 DOI: 10.3390/pathogens9110926] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/04/2020] [Accepted: 11/04/2020] [Indexed: 12/26/2022] Open
Abstract
Equine piroplasmosis (EP), caused by the hemoparasites Theileria equi, Theileria haneyi, and Babesia caballi, is an important tick-borne disease of equines that is prevalent in most parts of the world. Infection may affect animal welfare and has economic impacts related to limitations in horse transport between endemic and non-endemic regions, reduced performance of sport horses and treatment costs. Here, we analyzed the epidemiological, serological, and molecular diagnostic data published in the last 20 years, and all DNA sequences submitted to GenBank database, to describe the current global prevalence of these parasites. We demonstrate that EP is endemic in most parts of the world, and that it is spreading into more temperate climates. We emphasize the importance of using DNA sequencing and genotyping to monitor the spread of parasites, and point to the necessity of further studies to improve genotypic characterization of newly recognized parasite species and strains, and their linkage to virulence.
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Affiliation(s)
- Sharon Tirosh-Levy
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; (Y.G.); (A.S.)
| | - Yuval Gottlieb
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; (Y.G.); (A.S.)
| | - Lindsay M. Fry
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (L.M.F.); (D.P.K.)
- Animal Disease Research Unit, Agricultural Research Service, US Department of Agriculture, Pullman, WA 99164, USA
| | - Donald P. Knowles
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (L.M.F.); (D.P.K.)
| | - Amir Steinman
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; (Y.G.); (A.S.)
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