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Gondim LFP, Soares RM, Moré G, Jesus RFD, Llano HAB. Sarcocystis neurona and related Sarcocystis spp. shed by opossums (Didelphis spp.) in South America. ACTA ACUST UNITED AC 2021; 30:e006521. [PMID: 34259741 DOI: 10.1590/s1984-29612021059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/31/2021] [Indexed: 11/22/2022]
Abstract
Protozoan parasites of the genus Sarcocystis are obligatory heteroxenous cyst-forming coccidia that infect a wide variety of animals and encompass approximately 200 described species. At least four Sarcocystis spp. (S. falcatula, S. neurona, S. lindsayi and S. speeri) use opossums (Didelphis spp.) as definitive hosts, and two of them, S. neurona and S. falcatula, are known to cause disease in horses and birds, respectively. Opossums are restricted to the Americas, but their distribution in the Americas is heterogeneous. Five Didelphis spp. are distributed in South America (D. aurita, D. albiventris, D. marsupialis, D. imperfecta and D. pernigra) whereas just one opossum species (D. virginiana) is found in North America. Studies conducted in the last decades show that Sarcocystis spp., derived from South American Didelphis spp., have biological and genetic differences in relation to Sarcocystis spp. shed by the North American opossum D. virginiana. The aim of this review was to address the peculiar scenario of Sarcocystis species shed by South American opossums, with a special focus on diagnosis, epidemiology, and animal infections, as well as the genetic characteristics of these parasites.
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Affiliation(s)
- Luís Fernando Pita Gondim
- Departamento de Anatomia, Patologia e Clínicas, Escola de Medicina Veterinária e Zootecnia, Universidade Federal da Bahia - UFBA, Salvador, BA, Brasil
| | - Rodrigo Martins Soares
- Departamento de Medicina Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo - USP, São Paulo, SP, Brasil
| | - Gastón Moré
- Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Buenos Aires, Argentina.,Laboratorio de Inmunoparasitología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
| | - Rogério Fernando de Jesus
- Departamento de Anatomia, Patologia e Clínicas, Escola de Medicina Veterinária e Zootecnia, Universidade Federal da Bahia - UFBA, Salvador, BA, Brasil
| | - Horwald Alexander Bedoya Llano
- Grupo de Investigación - GINVER, Facultad de Medicina Veterinaria, Corporación Universitaria Remington, Medellín, Colombia
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Zitzer NC, Marsh AE, Burkhard MJ, Radin MJ, Wellman ML, Jugan M, Parker V. Parasitemia due to Sarcocystis neurona-like infection in a clinically ill domestic cat. Vet Clin Pathol 2017; 46:526-532. [PMID: 28892190 DOI: 10.1111/vcp.12541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An 8-year-old, 6-kg, male neutered Domestic Shorthair cat was presented to The Ohio State University Veterinary Medical Center (OSU-VMC) for difficulty breathing. Physical examination and thoracic radiographs indicated pneumonia, a soft-tissue mass in the left caudal lung lobe, and diffuse pleural effusion. The effusion was classified as modified transudate. Rare extracellular elongated (~5-7 μm × 1-2 μm) zoites with a central round to oval-shaped purple to deep purple vesicular nucleus with coarsely stippled chromatin and light blue cytoplasm were seen on a peripheral blood smear. Serum IgG and IgM were positive for Sarcocystis sp. antibodies and negative for Toxoplasma gondii antibodies, suggesting that the infection was acute rather than a recrudescence of prior infection. This organism was most consistent with either Sarcocystis neurona or Sarcocystis dasypi based on DNA sequence analysis of PCR products using COC ssRNA, ITS-1, snSAG2, and JNB25/JD396 primer sets. This is the first report to visualize by light microscopy circulating Sarcocystis sp. merozoites in the peripheral blood of a domestic cat. Therefore, Sarcocystis should be considered as a differential diagnosis in cats with suspected systemic protozoal infection.
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Affiliation(s)
- Nina C Zitzer
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Antoinette E Marsh
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Mary Jo Burkhard
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - M Judith Radin
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Maxey L Wellman
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Maria Jugan
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Valerie Parker
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
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Marsh AE, Chaney SB, Howe DK, Saville WJ, Reed SM. Small sarcocysts can be a feature of experimental infections with Sarcocystis neurona merozoites. Vet Parasitol 2017; 245:116-118. [PMID: 28969829 DOI: 10.1016/j.vetpar.2017.08.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/20/2017] [Accepted: 08/23/2017] [Indexed: 11/18/2022]
Abstract
Several reports indicate the presence of small tissue cysts associated with Sarcocystis neurona infections. Several failed attempts to develop tissue cysts in potential intermediate host using in vitro derived parasites originally isolated from horses with equine protozoal myeloencephalitis suggest that the experimental methods to achieve bradyzoites with those isolates was not possible. Those prior studies reported the lack of detectable sarcocysts based on histology and in vivo feeding trials. A recent report of successful production and detection of small sarcocysts triggered us to review archived tissues from earlier experimental infection studies. The retrospective review sought to determine if small sized sarcocysts were not detected due to their relatively smaller size and infrequency as compared to larger sized sarcocysts produced with other isolates in these experimental inoculation trials. Tissues from two prior in vivo inoculation studies, involving in vitro-produced parasites inoculated into laboratory-reared cats and raccoons, were re-examined by immunohistochemistry staining to more easily detect the tissue cysts. In the experimental cat study no small tissue cysts were seen, consistent with the original publication results. However, in the experimental raccoon study, one raccoon inoculated with an EPM-derived isolate, SN-UCD1, had small sarcocysts not reported in the original publication. This retrospective study suggests that much closer scrutiny of tissues, including the use of immunohistochemistry on tissue sections is required to detect the smaller S. neurona sarcocysts associated with the experimental inoculations of the isolates originally derived from horses with EPM.
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Affiliation(s)
- Antoinette E Marsh
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, OH, 43210, USA.
| | - Sarah B Chaney
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, OH, 43210, USA
| | - Daniel K Howe
- Department of Veterinary Science, University of Kentucky, 108 Gluck Equine Research Center, Lexington, KY, 40546, USA
| | - William J Saville
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, OH, 43210, USA
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Gondim LSQ, Jesus RF, Ribeiro-Andrade M, Silva JCR, Siqueira DB, Marvulo MFV, Aléssio FM, Mauffrey JF, Julião FS, Savani ESMM, Soares RM, Gondim LFP. Sarcocystis neurona and Neospora caninum in Brazilian opossums (Didelphis spp.): Molecular investigation and in vitro isolation of Sarcocystis spp. Vet Parasitol 2017; 243:192-198. [PMID: 28807293 DOI: 10.1016/j.vetpar.2017.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 06/12/2017] [Accepted: 07/04/2017] [Indexed: 11/19/2022]
Abstract
Sarcocystis neurona and Neospora spp. are protozoan parasites that induce neurological diseases in horses and other animal species. Opossums (Didelphis albiventris and Didelphis virginiana) are definitive hosts of S. neurona, which is the major cause of equine protozoal myeloencephalitis (EPM). Neospora caninum causes abortion in cattle and infects a wide range of animal species, while N. hughesi is known to induce neurologic disease in equids. The aims of this study were to investigate S. neurona and N. caninum in tissues from opossums in the northeastern Brazil, and to isolate Brazilian strains of Sarcocystis spp. from wild opossums for comparison with previously isolated strains. Carcasses of 39 opossums from Bahia state were available for molecular identification of Sarcocystis spp. and N. caninum in their tissues, and for sporocyst detection by intestinal scraping. In addition, Sarcocystis-like sporocysts from nine additional opossums, obtained in São Paulo state, were tested. Sarcocystis DNA was found in 16 (41%) of the 39 opossums' carcasses; N. caninum DNA was detected in tissues from three opossums. The sporocysts from the nine additional opossums from São Paulo state were tested by bioassay and induced infection in nine budgerigars, but in none of the gamma-interferon knockout mice. In vitro isolation was successful using tissues from all nine budgerigars. The isolated strains were maintained in CV-1 and Vero cells. Three of nine isolates presented contamination in cell culture and were discarded. Analysis of six isolates based on five loci showed that these parasites were genetically different from each other and also distinct from S. neurona, S. falcatula, S. lindsayi, and S. speeri. In conclusion, opossums in the studied regions were infected with N. caninum and Sarcocystis spp. and represent a potential source of infection to other animals. This is the first report of N. caninum infection in tissues from black-eared opossum (D. aurita or D. marsupialis) and white-eared opossum (D. albiventris). Brazilian opossums are probably infected by different Sarcocystis spp. distinct from S. neurona and S. falcatula, or present a high level of genetic recombination.
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Affiliation(s)
- Leane S Q Gondim
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil
| | - Rogério F Jesus
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil
| | - Müller Ribeiro-Andrade
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil
| | - Jean C R Silva
- Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos, Recife 52171-900, Pernambuco, Brazil; Instituto Brasileiro para Medicina da Conservação - Tríade, Rua Silveira Lobo 32, Caixa Postal 38, Casa Forte, Recife 532061-030, Pernambuco, Brazil
| | - Daniel B Siqueira
- Instituto Brasileiro para Medicina da Conservação - Tríade, Rua Silveira Lobo 32, Caixa Postal 38, Casa Forte, Recife 532061-030, Pernambuco, Brazil
| | - Maria F V Marvulo
- Faculdade Max Planck, Rodovia João Ceccon 60, Altos da Bela Vista, Indaiatuba 13331-400, São Paulo, Brazil; Instituto Brasileiro para Medicina da Conservação - Tríade, Rua Silveira Lobo 32, Caixa Postal 38, Casa Forte, Recife 532061-030, Pernambuco, Brazil
| | - Felipe M Aléssio
- Instituto de Ciências Biológicas da Universidade de Pernambuco, Rua Arnóbio Marques, 310, Santo Amaro, Recife 50100-130, Pernambuco, Brazil; Laboratoire Population Environnement Développement, IRD Aix-Marseille Université, Centre St Charles, Case 10 3, place Victor Hugo 13331 Marseille, Cedex 03 France
| | - Jean-François Mauffrey
- Laboratoire Population Environnement Développement, IRD Aix-Marseille Université, Centre St Charles, Case 10 3, place Victor Hugo 13331 Marseille, Cedex 03 France
| | - Fred S Julião
- Instituto Federal Baiano, Campus Santa Inês, Salvador, Bahia, Brazil
| | | | - Rodrigo M Soares
- Departamento de Medicina Veterinária Preventiva e Saúde Animal (VPS), Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87-Cidade Universitária, São Paulo, SP, 05508 270, Brazil
| | - Luís F P Gondim
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil.
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Chaney SB, Marsh AE, Lewis S, Carman M, Howe DK, Saville WJ, Reed SM. Sarcocystis neurona manipulation using culture-derived merozoites for bradyzoite and sporocyst production. Vet Parasitol 2017; 238:35-42. [PMID: 28372843 DOI: 10.1016/j.vetpar.2017.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/11/2017] [Accepted: 03/16/2017] [Indexed: 11/28/2022]
Abstract
Equine protozoal myeloencephalitis (EPM) remains a significant central nervous system disease of horses in the American continents. Sarcocystis neurona is considered the primary causative agent and its intermediate life stages are carried by a wide host-range including raccoons (Procyon lotor) in North America. S. neurona sarcocysts mature in raccoon skeletal muscle and can produce central nervous system disease in raccoons, mirroring the clinical presentation in horses. The study aimed to develop laboratory tools whereby the life cycle and various life stages of S. neurona could be better studied and manipulated using in vitro and in vivo systems and compare the biology of two independent isolates. This study utilized culture-derived parasites from S. neurona strains derived from a raccoon or from a horse to initiate raccoon infections. Raccoon tissues, including fresh and cryopreserved tissues, were used to establish opossum (Didelphis virginiana) infections, which then shed sporocyts with retained biological activity to cause encephalitis in mice. These results demonstrate that sarcocysts can be generated using in vitro-derived S. neurona merozoites, including an isolate originally derived from a naturally infected horse with clinical EPM. This study indicates the life cycle can be significantly manipulated in the laboratory without affecting subsequent stage development, allowing further purification of strains and artificial maintenance of the life cycle.
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Affiliation(s)
- Sarah B Chaney
- Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, United States
| | - Antoinette E Marsh
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, United States.
| | - Stephanie Lewis
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, United States
| | - Michelle Carman
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, United States
| | - Daniel K Howe
- Department of Veterinary Science, University of Kentucky, 108 Gluck Equine Research Center, Lexington, KY, 40546, United States
| | - William J Saville
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, United States
| | - Stephen M Reed
- Rood & Riddle, Equine Hospital, Lexington, KY, 40511, United States
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Verma SK, Calero-Bernal R, Lovallo MJ, Sweeny AR, Grigg ME, Dubey JP. Detection of Sarcocystis spp. infection in bobcats (Lynx rufus). Vet Parasitol 2015; 212:422-6. [PMID: 26138150 DOI: 10.1016/j.vetpar.2015.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/05/2015] [Accepted: 06/08/2015] [Indexed: 11/16/2022]
Abstract
The protozoan Sarcocystis neurona is an important cause of severe clinical disease of horses (called equine protozoal myeloencephalitis, EPM), marine mammals, companion animals, and several species of wildlife animals in the Americas. The Virginia opossum (Didelphis virginiana) is its definitive host in the USA and other animals act as intermediate or aberrant hosts. Samples of tongue and heart from 35 bobcats hunted for fur and food from Mississippi State, USA in February, 2014 were used for the present study. Muscles were examined for Sarcocystis infection by microscopic examination of either unfixed muscle squash preparations or pepsin digests, by histopathology of fixed samples, and by molecular methods. Sarcocystis-like bradyzoites were found in digests of 14 hearts and 10 tongues of 35 bobcats. In histological sections, sarcocysts were found in 26 of 35 bobcats; all appeared relatively thin-walled similar to S. felis sarcocysts under light microscope at 1000× magnification. S. neurona-like sarcocysts having thickened villar tips were seen in unstained muscle squash of tongue of two bobcats and PCR-DNA sequencing identified them definitively as S. neurona-like parasites. DNA extracted from bradyzoites obtained from tongue and heart muscle digests was analyzed by PCR-DNA sequencing at the ITS1 locus. Results indicated the presence of S. neurona-like parasite in 26 of 35 samples. ITS1 sequences identical to S. dasypi were identified in 3 bobcats, 2 of which were also co-infected with S. neurona-like parasite. The high prevalence of sarcocysts in bobcat tissues suggested an efficient sylvatic cycle of Sarcocystis spp. in the remote regions of Mississippi State with the bobcat as a relevant intermediate host.
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Affiliation(s)
- S K Verma
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, MD 20705-2350, USA
| | - R Calero-Bernal
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, MD 20705-2350, USA
| | - M J Lovallo
- Game Mammals Section, Bureau of Wildlife Management, Pennsylvania Game Commission, 2001 Elmerton Ave, Harrisburg, PA 17110, USA
| | - A R Sweeny
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - M E Grigg
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - J P Dubey
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, MD 20705-2350, USA.
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Dryburgh EL, Marsh AE, Dubey JP, Howe DK, Reed SM, Bolten KE, Pei W, Saville WJA. Sarcocyst Development in Raccoons (Procyon lotor) Inoculated with Different Strains of Sarcocystis neurona Culture-Derived Merozoites. J Parasitol 2015; 101:462-7. [PMID: 25811893 DOI: 10.1645/15-718.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (EPM), a neurological disease in horses. Raccoon ( Procyon lotor ) is considered the most important intermediate host in the life cycle of S. neurona in the United States; S. neurona sarcocysts do mature in raccoon muscles, and raccoons also develop clinical signs simulating EPM. The focus of this study was to determine if sarcocysts would develop in raccoons experimentally inoculated with different host-derived strains of in vitro-cultivated S. neurona merozoites. Four raccoons were inoculated with strains derived from a raccoon, a sea otter, a cat, and a horse. Raccoon tissues were fed to laboratory-raised opossums ( Didelphis virginiana ), the definitive host of S. neurona . Intestinal scraping revealed sporocysts in opossums who received muscle tissue from raccoons inoculated with the raccoon-derived or the sea otter-derived isolates. These results demonstrate that sarcocysts can mature in raccoons inoculated with in vitro-derived S. neurona merozoites. In contrast, the horse and cat-derived isolates did not produce microscopically or biologically detected sarcocysts. Immunoblot analysis revealed both antigenic and antibody differences when testing the inoculated raccoons. Immunohistochemical staining indicated differences in staining between the merozoite and sarcocyst stages. The successful infections achieved in this study indicates that the life cycle can be manipulated in the laboratory without affecting subsequent stage development, thereby allowing further purification of strains and artificial maintenance of the life cycle.
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Affiliation(s)
- E L Dryburgh
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
| | - A E Marsh
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
| | - J P Dubey
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
| | - D K Howe
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
| | - S M Reed
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
| | - K E Bolten
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
| | - W Pei
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
| | - W J A Saville
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210
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Dubey JP, Howe DK, Furr M, Saville WJ, Marsh AE, Reed SM, Grigg ME. An update on Sarcocystis neurona infections in animals and equine protozoal myeloencephalitis (EPM). Vet Parasitol 2015; 209:1-42. [PMID: 25737052 DOI: 10.1016/j.vetpar.2015.01.026] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 01/27/2023]
Abstract
Equine protozoal myeloencephalitis (EPM) is a serious disease of horses, and its management continues to be a challenge for veterinarians. The protozoan Sarcocystis neurona is most commonly associated with EPM. S. neurona has emerged as a common cause of mortality in marine mammals, especially sea otters (Enhydra lutris). EPM-like illness has also been recorded in several other mammals, including domestic dogs and cats. This paper updates S. neurona and EPM information from the last 15 years on the advances regarding life cycle, molecular biology, epidemiology, clinical signs, diagnosis, treatment and control.
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Affiliation(s)
- J P Dubey
- United States Department of Agriculture, Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Building 1001, Beltsville, MD 20705-2350, USA.
| | - D K Howe
- M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, USA
| | - M Furr
- Marion du Pont Scott Equine Medical Center, Virginia Maryland Regional College of Veterinary Medicine, 17690 Old Waterford Road, Leesburg, VA 20176, USA
| | - W J Saville
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | - A E Marsh
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | - S M Reed
- Rood and Riddle Equine Hospital, Lexington, KY 40511, USA
| | - M E Grigg
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institutes of Allergy, and Infectious Diseases, 4 Center Drive, Room B1-06, Bethesda, MD 20892, USA
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Sarcocystis sp. from the herring gull (Larus argentatus) identity to Sarcocystis wobeseri based on cyst morphology and DNA results. Parasitol Res 2011; 109:1603-8. [DOI: 10.1007/s00436-011-2421-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 04/15/2011] [Indexed: 10/18/2022]
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Wendte JM, Miller MA, Lambourn DM, Magargal SL, Jessup DA, Grigg ME. Self-mating in the definitive host potentiates clonal outbreaks of the apicomplexan parasites Sarcocystis neurona and Toxoplasma gondii. PLoS Genet 2010; 6:e1001261. [PMID: 21203443 PMCID: PMC3009688 DOI: 10.1371/journal.pgen.1001261] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 11/23/2010] [Indexed: 12/24/2022] Open
Abstract
Tissue-encysting coccidia, including Toxoplasma gondii and Sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. During its sexual life stage, T. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. Out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. In contrast, selfing and other life history traits, such as asexual expansion of tissue-cysts by oral transmission among intermediate hosts, have been proposed to explain the genetic basis for the clonal population structure of T. gondii. In this study, we investigated the contributing roles self-mating and sexual recombination play in nature to maintain clonal population structures and produce or expand parasite clones capable of causing disease epidemics for two tissue encysting parasites. We applied high-resolution genotyping against strains isolated from a T. gondii waterborne outbreak that caused symptomatic disease in 155 immune-competent people in Brazil and a S. neurona outbreak that resulted in a mass mortality event in Southern sea otters. In both cases, a single, genetically distinct clone was found infecting outbreak-exposed individuals. Furthermore, the T. gondii outbreak clone was one of several apparently recombinant progeny recovered from the local environment. Since oocysts or sporocysts were the infectious form implicated in each outbreak, the expansion of the epidemic clone can be explained by self-mating. The results also show that out-crossing preceded selfing to produce the virulent T. gondii clone. For the tissue encysting coccidia, self-mating exists as a key adaptation potentiating the epidemic expansion and transmission of newly emerged parasite clones that can profoundly shape parasite population genetic structures or cause devastating disease outbreaks. The parasites Toxoplasma gondii and Sarcocystis neurona have lifecycles that include a sexual stage in a definitive host and an asexual stage in intermediate hosts. For T. gondii, laboratory studies have demonstrated that the sexual stage can serve the dual purpose of producing new, virulent genotypes through recombination and promoting expansion of single clones via self-mating. Self-mating and other life history traits of T. gondii, including transmission of asexual stages among intermediate hosts, are assumed to account for the clonal population genetic structure of this organism. However, the relative contributions of sexual recombination and self-mating verses other life history traits in causing disease outbreaks or in shaping Toxoplasma's population genetic structure have not been verified in nature, nor have these traits been extensively examined in related parasites. To address this knowledge gap, we conducted population genetic analyses on T. gondii and S. neurona strains isolated from naturally occurring outbreaks affecting humans and sea otters, respectively. Our results identify self-mating as a key trait potentiating disease outbreaks through the rapid amplification of a single clone into millions of infectious units. Selfing is likely a key adaptation for enhancing transmission of recently emerged, recombinant clones and reshaping population genetic structures among the tissue-cyst coccidia.
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Affiliation(s)
- Jered M. Wendte
- Molecular Parasitology Unit, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Veterinary Pathobiology, Oklahoma State University Center for Veterinary Health Sciences, Stillwater, Oklahoma, United States of America
- Howard Hughes Medical Institute–National Institutes of Health Research Scholars Program, Bethesda, Maryland, United States of America
| | - Melissa A. Miller
- Marine Wildlife Veterinary Care and Research Center (CDFG-OSPR), Santa Cruz, California, United States of America
| | - Dyanna M. Lambourn
- Washington Department of Fish and Wildlife, Lakewood, Washington, United States of America
| | - Spencer L. Magargal
- Molecular Parasitology Unit, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - David A. Jessup
- Marine Wildlife Veterinary Care and Research Center (CDFG-OSPR), Santa Cruz, California, United States of America
| | - Michael E. Grigg
- Molecular Parasitology Unit, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Veterinary Pathobiology, Oklahoma State University Center for Veterinary Health Sciences, Stillwater, Oklahoma, United States of America
- * E-mail:
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11
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Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California. Vet Parasitol 2010; 170:20-9. [PMID: 20226596 DOI: 10.1016/j.vetpar.2009.12.045] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 12/15/2009] [Accepted: 12/15/2009] [Indexed: 11/22/2022]
Abstract
Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums.
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12
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Has Sarcocystis neurona Dubey et al., 1991 (Sporozoa: Apicomplexa: Sarcocystidae) cospeciated with its intermediate hosts? Vet Parasitol 2009; 163:307-14. [DOI: 10.1016/j.vetpar.2009.03.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 03/03/2009] [Accepted: 03/09/2009] [Indexed: 11/20/2022]
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Miller MA, Barr BC, Nordhausen R, James ER, Magargal SL, Murray M, Conrad PA, Toy-Choutka S, Jessup DA, Grigg ME. Ultrastructural and molecular confirmation of the development of Sarcocystis neurona tissue cysts in the central nervous system of southern sea otters (Enhydra lutris nereis). Int J Parasitol 2009; 39:1363-72. [PMID: 19527725 DOI: 10.1016/j.ijpara.2009.04.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 04/05/2009] [Accepted: 04/07/2009] [Indexed: 10/20/2022]
Abstract
In 2004, three wild sea otters were diagnosed with putative Sarcocystis neurona-associated meningoencephalitis by histopathology and immunohistochemistry. Schizonts, free merozoites and tissue cysts were observed in the brains of all three infected animals. Tissue cysts walls from sea otter 1 (SO1) stained positively using anti-S. neurona polyclonal antiserum. However, positive staining does not preclude infection by closely related or cross-reactive tissue cyst-forming coccidian parasites. Two immature tissue cysts in the brain of SO1 were examined using transmission electron microscopy. Ultrastructural features included cyst walls with thin villous projections up to 1 microm long with tapered ends and a distinctive, electron-dense outer lining layer composed of linearly-arranged, semi-circular structures with a "hobnailed" surface contour. Small numbers of microtubules extended down through the villi into the underlying granular layer. Metrocytes were short and plump with an anterior apical complex, 22 sub-pellicular microtubules, numerous free ribosomes and no rhoptries. Some metrocytes appeared to be dividing, with two adjacent nuclear profiles. Collectively these ultrastructural features were compatible with developing protozoal cysts and were similar to prior descriptions of S. neurona tissue cysts. Panspecific 18S rDNA primers were utilized to identify protozoa infecting the brains of these otters and DNA amplification and additional sequencing at the ITS1 locus confirmed that all three otters were infected with S. neurona. No other Sarcocystis spp. were detected in the brains or skeletal muscles of these animals by immunohistochemistry or PCR. We believe this is the first ultrastructural and molecular confirmation of the development of S. neurona tissue cysts in the CNS of any animal.
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Affiliation(s)
- M A Miller
- Marine Wildlife Veterinary Care and Research Center, California Department of Fish and Game, 1451 Shaffer Road, Santa Cruz, CA 95060, USA.
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14
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Mansfield L, Mehler S, Nelson K, Elsheikha H, Murphy A, Knust B, Tanhauser S, Gearhart P, Rossano M, Bowman D, Schott H, Patterson J. Brown-headed cowbirds (Molothrus ater) harbor Sarcocystis neurona and act as intermediate hosts. Vet Parasitol 2008; 153:24-43. [DOI: 10.1016/j.vetpar.2007.12.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 11/26/2007] [Accepted: 12/04/2007] [Indexed: 11/25/2022]
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15
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Elsheikha HM, Mansfield LS. Molecular typing of Sarcocystis neurona: current status and future trends. Vet Parasitol 2007; 149:43-55. [PMID: 17706872 DOI: 10.1016/j.vetpar.2007.06.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 06/20/2007] [Accepted: 06/22/2007] [Indexed: 11/26/2022]
Abstract
Sarcocystis neurona is an important protozoal pathogen because it causes the serious neurological disease equine protozoal myeloencephalitis (EPM). The capacity of this organism to cause a wide spectrum of neurological signs in horses and the broad geographic distribution of observed cases in the Americas drive the need for sensitive, reliable and rapid typing methods to characterize strains. Various molecular methods have been developed and used to diagnose EPM due to S. neurona, to identify S. neurona isolates and to determine the heterogeneity and evolutionary relatedness within this species and related Sarcocystis spp. These methods included sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immuno-fluorescent assay (IFA), slide agglutination test (SAT), SnSAG-specific ELISA, random amplified polymorphic DNA (RAPD), PCR-based restriction fragment length polymorphism (RFLP), amplified fragment length polymorphism (AFLP) fingerprinting, and sequence analysis of surface protein genes, ribosomal genes, microsatellite alleles and other molecular markers. Here, the utility of these molecular methods is reviewed and evaluated with respect to the need for molecular approaches that utilize well-characterized polymorphic, simple, independent, and stable genetic markers. These tools have the potential to add to knowledge of the genetic population structure of S. neurona and to provide new insights into the pathogenesis of EPM and S. neurona epidemiology. In particular, these methods provide new tools to address the hypothesis that particular genetic variants are associated with adverse clinical outcomes (severe pathotypes). The ultimate goal is to utilize them in future studies to improve treatment and prevention strategies.
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Affiliation(s)
- Hany M Elsheikha
- Division of Veterinary Medicine, The School of Veterinary Medicine and Science, The University of Nottingham, College Road, Sutton Bonington, Leicestershire LE12 5RD, United Kingdom
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Lindsay DS, Mitchell SM, Yang J, Dubey JP, Gogal RM, Witonsky SG. Penetration of equine leukocytes by merozoites of Sarcocystis neurona. Vet Parasitol 2006; 138:371-6. [PMID: 16517080 DOI: 10.1016/j.vetpar.2006.01.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Revised: 01/27/2006] [Accepted: 01/28/2006] [Indexed: 01/07/2023]
Abstract
Horses are considered accidental hosts for Sarcocystis neurona and they often develop severe neurological disease when infected with this parasite. Schizont stages develop in the central nervous system (CNS) and cause the neurological lesions associated with equine protozoal myeloencephalitis. The present study was done to examine the ability of S. neurona merozoites to penetrate and develop in equine peripheral blood leukocytes. These infected host cells might serve as a possible transport mechanism into the CNS. S. neurona merozoites penetrated equine leukocytes within 5 min of co-culture. Infected leukocytes were usually monocytes. Infected leukocytes were present up to the final day of examination at 3 days. Up to three merozoites were present in an infected monocyte. No development to schizont stages was observed. All stages observed were in the host cell cytoplasm. We postulate that S. neurona merozoites may cross the blood brain barrier hidden inside leukocytes. Once inside the CNS these merozoites can egress and invade additional cells and cause encephalitis.
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Affiliation(s)
- David S Lindsay
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, 1410 Prices Fork Road, Blacksburg, 24061-0342, USA.
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Gupta GD, Lakritz J, Saville WJ, Livingston RS, Dubey JP, Middleton JR, Marsh AE. Antigenic evaluation of a recombinant baculovirus-expressed Sarcocystis neurona SAG1 antigen. J Parasitol 2004; 90:1027-33. [PMID: 15562602 DOI: 10.1645/0022-3395(2004)090[1027:aeoarb]2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Sarcocystis neurona is the primary parasite associated with equine protozoal myeloencephalitis (EPM). This is a commonly diagnosed neurological disorder in the Americas that infects the central nervous system of horses. Current serologic assays utilize culture-derived parasites as antigen. This method requires large numbers of parasites to be grown in culture, which is labor intensive and time consuming. Also, a culture-derived whole-parasite preparation contains conserved antigens that could cross-react with antibodies against other Sarcocystis species and members of Sarcocystidae such as Neospora spp., Hammondia spp., and Toxoplasma gondii. Therefore, there is a need to develop an improved method for the detection of S. neurona-specific antibodies. The sera of infected horses react strongly to surface antigen 1 (SnSAG1), an approximately 29-kDa protein, in immunoblot analysis, suggesting that it is an immunodominant antigen. The SnSAG1 gene of S. neurona was cloned, and recombinant S. neurona SAG1 protein (rSnSAG1-Bac) was expressed with the use of a baculovirus system. By immunoblot analysis, the rSnSAG1-Bac antigen detected antibodies to S. neurona from naturally infected and experimentally inoculated equids, cats, rabbit, mice, and skunk. This is the first report of a baculovirus-expressed recombinant S. neurona antigen being used to detect anti-S. neurona antibodies in a variety of host species.
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Affiliation(s)
- G D Gupta
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri 65211, USA
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Gillis KD, MacKay RJ, Yowell CA, Levy JK, Greiner EC, Dame JB, Cheadle MA, Hernandez J, Massey ET. Naturally occurring Sarcocystis infection in domestic cats (Felis catus). Int J Parasitol 2003; 33:877-83. [PMID: 12865087 DOI: 10.1016/s0020-7519(03)00090-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Equine protozoal myeloencephalitis is an important neurological disease of horses in the United States. Consequently, there is an active research effort to identify hosts associated with the primary causative agent, Sarcocystis neurona. The purpose of this study was to determine whether the domestic cat (Felis catus) is a natural host for S. neurona. Muscle sections from 50 primarily free-roaming domestic cats were examined for the presence of sarcocysts. Serum from cats in this group and another group of 50 free-roaming cats were evaluated for the presence of S. neurona antibody. Sarcocysts were found in five of 50 (10%) cats, and S. neurona antibody in five of 100 (5%) cats. Morphological, molecular (including ribosomal RNA genes), and biological characterisation of these sarcocysts showed that they were not S. neurona or S. neurona-like. Sarcocysts found in the cats were identified morphologically as Sarcocystis felis, a common parasite of wild felids. The life cycle of S. felis is not known, and prior to this study, no molecular marker for S. felis existed. Although cats were found to be infected with S. felis sarcocysts, serological data provided evidence of possible infection with S. neurona as well. Further work is needed to determine the role of the domestic cat in the life cycle of S. neurona.
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Affiliation(s)
- K D Gillis
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, FL 32610, USA.
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Dubey JP, Benson J, Larson MA. Clinical Sarcocystis neurona encephalomyelitis in a domestic cat following routine surgery. Vet Parasitol 2003; 112:261-7. [PMID: 12623205 DOI: 10.1016/s0304-4017(03)00019-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Sarcocystis neurona is an important cause of equine protozoal myeloencephalitis (EPM) in horses in the Americas. An EPM-like neurological disease also has been reported from other mammals but it is difficult to induce this disease in the laboratory. A 4-month-old male domestic cat developed neurological signs 3 days following castration. The cat was euthanized 12 days later because of paralysis. Encephalomyelitis was the only lesion and was associated with numerous Sarcocystis schizonts and merozoites in the brain and spinal cord. The protozoa reacted positively with S. neurona-specific polyclonal rabbit antibody. Two unidentified sarcocysts were present in the cerebellum. It may be possible that stress of surgery triggered relapse of S. neurona infection in this cat.
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Affiliation(s)
- J P Dubey
- Parasite Biology, Epidemiology and Systematics Laboratory, Agricultural Research Service, US Department of Agriculture, Animal and Natural Resources Institute, Beltsville Agricultural Research Center, MD 20705-2350, USA.
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