Protozoa are single-celled eukaryotic organisms that can interact with horses in various ways, including as parasites. In equine health, protozoal infections can lead to significant diseases, such as equine protozoal myeloencephalitis (EPM), which is caused by the protozoan Sarcocystis neurona. These organisms can affect the central nervous system and other bodily systems, leading to a range of clinical symptoms in horses. Understanding the life cycle, transmission, and impact of protozoa is important for managing and preventing infections. This page compiles peer-reviewed research studies and scholarly articles that explore the biology, pathogenesis, and diagnostic approaches related to protozoal interactions in horses.
Atwill ER, McDougald NK, Perea L.Faecal specimens from 305 horses and mules used as packstock at one of 17 commercial or governmental (National Park Service, US Forest Service) operations were examined for Giardia duodenalis and Cryptosporidium parvum using immunofluorescent microscopy. Fourteen packstock (4.6%) were shedding G. duodenalis cysts, with herd-level prevalences ranging 0-22%. Number of packstock in the corral, size of corral and density of packstock in the corral were associated with the odds of shedding G. duodenalis cysts. None of the horses had detectable C. parvum oocysts. Assuming a sensitivity of at least 4...
Rossano MG, Mansfield LS, Kaneene JB, Murphy AJ, Brown CM, Schott HC, Fox JC.Equine protozoal myeloencephalitis (EPM) is a neurological disease of horses and ponies caused by the apicomplexan protozoan parasite Sarcocystis neurona. The purposes of this study were to develop the most stringent criteria possible for a positive test result, to estimate the sensitivity and specificity of the EPM Western blot antibody test, and to assess the ability of bovine antibodies to Sarcocystis cruzi to act as a blocking agent to minimize false-positive results in the western blot test for S. neurona. Sarcocystis neurona merozoites harvested from equine dermal cell culture were heat ...
Dirikolu L, Lehner F, Nattrass C, Bentz BG, Woods WE, Carter WG, Karpiesiuk W, Jacobs J, Boyles J, Harkins JD, Granstrom DE, Tobin T.Diclazuril (4-chlorophenyl [2,6-dichloro-4-(4,5-dihydro-3H-3,5-dioxo-1,2,4-triazin-2-yl)pheny l] acetonitrile), is a benzeneacetonitrile antiprotozoal agent (Janssen Research Compound R 64433) marketed as Clinacox . Diclazuril may have clinical application in the treatment of Equine Protozoal Myeloencephalitis (EPM). To evaluate its bioavailability and preliminary pharmacokinetics in the horse we developed a sensitive quantitative high-pressure liquid chromatography (HPLC) method for diclazuril in equine biological fluids. MS/MS analysis of diclazuril in our HPLC solvent yielded mass spectral ...
Cheadle MA, Lindsay DS, Rowe S, Dykstra CC, Williams MA, Spencer JA, Toivio-Kinnucan MA, Lenz SD, Newton JC, Rolsma MD, Blagburn BL.An IFAT was used to determine the prevalence of Neospora-specific IgG antibodies in serum from Alabama horses. Serum samples (n = 536) were from asymptomatic horses routinely submitted for equine infectious anaemia virus infection testing. We also subjected a 13-year-old horse with CNS disease to necropsy examination for isolation and in vitro cultivation of protozoal organisms. In antemortem tests, this horse was positive for antibodies to Neospora sp. in the IFAT and western immunoblot. Results of the prevalence survey indicated that IgG antibodies to Neospora were present in 62 (11.5%) of t...
Murphy AJ, Mansfield LS.Sarcocystis neurona is a protozoan parasite that causes a neurological disease in horses called equine protozoal myeloencephalitis. The route of transmission is speculated to be by fecal-oral transfer of sporocysts shed from opossums. Controversy exists regarding both the natural life cycle for this parasite as well as the species identity of opossum Sarcocystis. To provide stage-specific material for species comparison, 27 opossums from southern Michigan were screened for Sarcocystis spp. sporocysts. Seven opossums were positive for Sarcocystis sporocysts by fecal flotation. A simplified, eff...
Davis CR, Barr BC, Pascoe JR, Olander HJ, Dubey JP.Hepatic sarcocystosis was diagnosed in a horse in association with refractory bacterial osteomyelitis and plasma cell tumor of the maxilla and hepatic salmonellosis. Gross lesions included pleural, pericardial, and peritoneal effusions, hepatomegaly, gastric ulceration, colonic edema, and proliferative tissues filling 2 maxillary dental alveoli. Histologically, liver was characterized by severe suppurative, necrotizing, periportal hepatitis, and severe periacinar necrosis. Hepatocytes frequently contained protozoal schizonts in various stages of development. In mature schizonts, merozoites wer...
Dubey JP, Kerber CE, Granstrom DE.To determine serologic prevalence of Sarcocystis neurona, Toxoplasma gondii, and Neospora caninum in horses in Brazil. Methods: Prevalence survey. Methods: 101 Thoroughbreds in Brazil. Methods: Blood samples were obtained from horses and tested for serum antibodies against S neurona by use of an immunoblot procedure with culture-derived S neurona merozoites as antigen, and for serum antibodies against T gondii and N caninum by use of a modified agglutination test with formalin-preserved tachyzoites and mercaptoethanol. Results: Antibodies against S neurona and T gondii were detected in 36 and ...
Dubey JP, Venturini MC, Venturini L, McKinney J, Pecoraro M.Sera from 76 horses from Argentina were examined for antibodies to Sarcocystis neurona, Toxoplasma gondii and Neospora caninum. Antibodies to S. neurona were found in 27 (35.5%) of 76 horses using immunoblots with culture derived merozoites as antigen. Antibodies to T. gondii were found in 10 (13.1%) of 76 horses by using the modified agglutination test with formalin-fixed tachyzoites and mercaptoethanol; titers were 1:25 (two horses), 1:50 (six horses), 1:100 (two horses), and 1:200 (one horse). Antibodies to N. caninum were not found in any of the 76 horses by the use of N. caninum agglutina...
Lindsay DS, Dubey JP.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. The activities of pyrimethamine, trimethoprim, sulfachloropyridazine, sulfadiazine, sulfadimethoxine, sulfamethoxazole, sulfamethazine, and sulfathiazole were examined against developing S. neurona merozoites in bovine turbinate cell cultures. A microtiter plate host cell lesion based assay was used to determine the effects of agents on developing merozoites. A cell culture flask assay was used to determine if sele...
Cutler TJ, MacKay RJ, Ginn PE, Greiner EC, Porter R, Yowell CA, Dame JB.Equine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease of the horse. The causative agent. Sarcocystis neurona, has been suggested to be synonymous with Sarcocystis falcatula, implying a role for birds as intermediate hosts. To test this hypothesis, opossums (Didelphis virginiana) were fed muscles containing S. falcatula sarcocysts from naturally infected brown-headed cowbirds (Molothrus ater). Ten horses were tested extensively to ensure no previous exposure to S. neurona and were quarantined for 14 days, and then 5 of the horses were each administered 10(6) S. falcatula...
Tanhauser SM, Yowell CA, Cutler TJ, Greiner EC, MacKay RJ, Dame JB.Studies designed to investigate the causative agent of equine protozoal myeloencephalitis and its life cycle have been hampered by the marked similarity of Sarcocystis neurona to other Sarcocystis spp. present in the same definitive host. Random-amplified polymorphic DNA techniques were used to amplify DNA from isolates of S. neurona and Sarcocystis falcatula. DNA sequence analysis of polymerase chain reaction (PCR) products was then used to design PCR primers to amplify specific Sarcocystis spp. DNA products. The ribosomal RNA internal transcribed spacer was also amplified and compared betwee...
Hamir AN, Tornquist SJ, Gerros TC, Topper MJ, Dubey JP.Equine protozoal myeloencephalitis (EPM) was clinically diagnosed in a 20-year-old horse with severe ataxia. The cerebrospinal fluid was positive for Sarcocystis neurona antibodies by western blot. The horse was administered corticosteroids to facilitate in vitro culture of S. neurona from its spinal cord following necropsy. Microscopic lesions of EPM were present in the brain and in the spinal cord, including multifocal inflammatory cellular infiltrates and several large groups of protozoa. Immunohistochemical, and light and electron microscopic examinations revealed that the protozoa were Ne...
Marsh AE, Barr BC, Packham AE, Conrad PA.Neospora hughesi n. sp. was isolated from the central nervous system tissue of an adult equine (Equus caballus) from California. The tachyzoites are crescent-shaped, approximately 2 x 5 microm (1.8-3.0 x 4.0-7.0 microm), with characteristic apical complex structures consisting of an anterior polar ring, conoid, numerous rhoptries filled with a uniform electron-dense material, and 22 microtubules extending posteriorly from the polar ring. Comparison of N. hughesi to canine and bovine Neospora caninum isolates showed phenotypic differences in immunoreactive proteins. Molecular analysis of the sm...
Soliman GA.The pharmacokinetic behaviour of gentamicin sulphate (3.4 mg/kg bwt) was studied following its intramuscular injection to a group of horses and to another group of horses premedicated with sodium methyl arsinate (2 mg/kg bwt) or imidocarb dipropionate (4.8 mg/kg bwt). Considerable differences were observed in the pharmacokinetics of gentamicin in pre-medicated horses and in horses which had received the antibiotic alone. Peak serum concentration of gentamicin (9.85 +/- 0.05 and 11.15 +/- 0.15 micrograms/ml) were attained within 1.45 +/- 0.05 and 0.92 +/- 0.04 h in arsinate and imidocarb-medica...
Olson ME, Thorlakson CL, Deselliers L, Morck DW, McAllister TA.Giardia intestinalis and Cryptosporidium spp. are commonly identified intestinal pathogens in humans and animals. In light of the clinical disease, production losses and zoonotic potential of both Giardia and Cryptosporidium infections, a study was undertaken to investigate the prevalence of these parasites in cattle, sheep, pigs and horses in Canadian farms at different geographical locations. A total of 104 cattle, 89 sheep, 236 pigs and 35 horses were sampled from 15 different Canadian geographical locations. Fecal samples were examined after concentration and immunofluorescent staining. Gi...
Bentz BG, Granstrom DE, Stamper S.To determine seroprevalence of Sarcocystis neurona-specific antibodies in a population of horses residing in Chester County, Pa. Methods: Prevalence survey. Methods: 117 serum samples from selected members of a population of 580 Thoroughbred horses. Methods: Serum was analyzed for antibodies to Sarcocystic neurona, using a western blot. Information regarding age, sex, and housing of horse was obtained by questionnaire. Data were analyzed, using multivariable logistic regression. Results: Seroprevalence was 45.3% (95% CI, 36.3 to 54.3%). A relationship was not found between seroprevalence and s...
Fenger CK, Granstrom DE, Gajadhar AA, Williams NM, McCrillis SA, Stamper S, Langemeier JL, Dubey JP.Sarcocystis sp. sporocysts isolated from eight feral opossums (Didelphis virginiana) were pooled and fed to 18 commercially reared budgerigars (Melopsittacus undulatus), 14 wild-caught sparrows (Passer domesticus), one wild-caught slate-colored Junco (Junco hyemalis) and five weanling horses (Equus caballus). All budgerigars died within 5 weeks post inoculation (wpi). Histologic examination revealed meronts within the pulmonary epithelia and typical Sarcocystis falcatula sarcocysts developing in the leg muscles. Sparrows were euthanized 13 and 17 wpi and their carcasses were fed to four labora...
Johnson E, Atwill ER, Filkins ME, Kalush J.Cryptosporidium parvum and Giardia duodenalis are now recognized as primary enteric pathogens in animals and humans. Regulatory agencies, such as the Environmental Protection Agency are under increasing pressure to reduce the concentration of these protozoa in surface waters. Given the popularity of recreational riding of horses on public land in California backcountry, concerns have been raised by various regulatory agencies as to whether horses used for backcountry recreation are a significant source of C. parvum and G. duodenalis for the environment. The prevalence of fecal shedding of Cryp...
Marsh AE, Barr BC, Madigan J, Lakritz J, Nordhausen R, Conrad PA.Neosporosis was diagnosed in an 11-year-old Quarter Horse gelding with clinical signs and diagnostic test results compatible with equine protozoal myeloencephalitis (EPM). Presumptive postmortem diagnosis of EPM attributable to Sarcocystis neurona infection is generally made on the basis of detecting an antibody titer to S neurona in the CSF or characteristic histologic lesions, even when parasites have not been specifically identified. Neosporosis was confirmed in the horse described here by use of immunohistochemical examination, in vitro culturing, and ultrastructural and molecular characte...
Marsh AE, Barr BC, Madigan J, Lakritz J, Conrad PA.To identify Sarcocystis neurona-specific DNA sequences in the nuclear small subunit ribosomal RNA (nss-rRNA) gene that could be used to distinguish S neurona from other closely related protozoal parasites, and to evaluate a polymerase chain reaction (PCR) test, using broad based primers and a unique species-specific probe on CSF for detection of S neurona in equids. Methods: Sequencing of the nuclear small subunit ribosomal RNA gene from a new S neurona isolate (UCD 1) was performed. The sequence was compared with that of other closely related Sarcocystidae parasites. From this sequence, conse...
French RA, Meier WA, Zachary JF.Tissues from a 9-year-old American Standardbred gelding with a history of anorexia, mild colic, and unexpected death were submitted to the Laboratories of Veterinary Diagnostic Medicine at the University of Illinois for histopathologic examination. Microscopic diagnoses were severe subacute, diffuse eosinophilic colitis with intralesional protozoa and a subacute to chronic eosinophilic portal hepatitis with granuloma formation. Two tissue-invading, ciliated protozoa were identified in large numbers within the colonic mucosa. The ciliates were Polymorphella ampulla and Cycloposthium sp., Phylum...
Ito A, Imai S, Ogimoto K, Nakahara M.The composition of intestinal ciliates excreted in the feces of 20 Tokara native ponies kept in Iriki farm of Kagoshima University was surveyed. Eleven genera consisting of 18 species were identified based on the description of Strelkow. One new genus including a new species, Wolskana tokarensis n. gen., n. sp., of the family Buetschliidae was recognized and described. The average ciliate density of all horses was 13.8 x 10(3)/ml. Those of stallions (n = 5), mares (n = 11) and foals (n = 4) were 3.9, 16.1 and 43.3 x 10(3)/ml respectively. The value of stallions was significantly lower and that...
Battelli G, Galuppi R, Pietrobelli M, Tampieri MP.Fecal examinations of horses (Equus caballus) from studs in the province of Udine (Friuli Venezia Giulia region, east-northern Italy), carried out during two periods of the year 1993, revealed coccidian oocysts in six foals, two stallions and one mare. The species was identified as Eimeria leuckarti. This species was reported only once in Italy, more than 20 years ago (1972). For this reason, the prevalence of the parasite and the description of immature and sporulated oocysts are given.
Fenger CK, Granstrom DE, Langemeier JL, Stamper S, Donahue JM, Patterson JS, Gajadhar AA, Marteniuk JV, Xiaomin Z, Dubey JP.Sarcocystis neurona is an apicomplexan that causes equine protozoal myeloencephalitis (EPM) in North and South America. Horses appear to be an aberrant host, because the merozoites continually divide in the central nervous system, without encysting. The natural host species has not previously been identified. The small subunit ribosomal RNA (SSURNA) gene of S. neurona was compared to those of Sarcocystis muris, Sarcocystis cruzi, Toxoplasma gondii, and Cryptosporidium parvum to identify a unique region suitable for a species-specific amplification primer. The S. neurona SSURNA primer was used ...
Dame JB, MacKay RJ, Yowell CA, Cutler TJ, Marsh A, Greiner EC.Equine protozoal myeloencephalitis (EPM) is a neurologic disease of horses caused by Sarcocystis neurona. The horse is a dead-end host for S. neurona and the definitive and intermediate hosts have not previously been identified. We hypothesized that S. neurona is actually Sarcocystis falcatula, a parasite that cycles in nature between Virginia opossums (Didelphis virginiana) and any of a variety of avian intermediate hosts. We extracted DNA from S. falcatula sarcocysts in the muscle of a brown-headed cowbird (Molothrus ater) and from schizonts in a fixed specimen of lung from a Moluccan cockat...
Pavlásek I, Hess L, Stehlík I, Stika V.The first occurrence of Giardia spp. in horses in the Czech Republic is reported. During preventive examination of 360 five-month up to 14-year horses from various parts of the region of Central Bohemia carried out from January 1993 to June 1994 in the parasitological laboratory of the State Veterinary Institute in Prague, the Giardia cysts were detected in the excrements of 18 (5%) horses, mostly 2-4 years of age, and in two foals 3 and 6 weeks old. During the period between March 1993 and June 1994, systematic and repeated observation was aimed at a group of 38 racing horses two up to four y...
Zweygarth E, Just MC, de Waal DT.The protozoan parasite Babesia equi, a causative agent of equine piroplasmosis, was continuously cultivated in horse erythrocytes. The parasites were isolated from a carrier horse at a time when no parasite was detected in a thin blood smear. The culture medium consisted of modified medium 199 supplemented with 40% non-heat-inactivated horse serum in a humidified atmosphere containing 5% CO2, 2% O2, and 93% N2 at 37 degrees C. Parasites were detected after 2 days in culture. When the percentage of parasitized erythrocytes (PPE) reached 1%, the cultures were transferred into a humidified atmosp...
The Journal of parasitologyFebruary 24, 2001
Volume 86, Issue 6 1366-1368 doi: 10.1645/0022-3395(2000)086[1366:ARAPDP]2.0.CO;2
Spencer JA, Witherow AK, Blagburn BL.Neospora caninum is a recently described coccidial parasite that was first isolated from a dog in 1988 and has subsequently been shown to infect a wide range of mammals. Neospora hughesi, a new species of this genus, has recently been isolated from the spinal cord of horses showing clinical signs of equine protozoal myeloencephalitis. The random amplified polymorphic DNA polymerase chain reaction technique is capable of differentiating between N. caninum and N. hughesi.
Ribeiro DSC, Martins AV, Lobão LF, Ribeiro MS, Palmer JPS, Corrêa LL, Uchôa CMA, da Silva S, Meireles MV, Amendoeira MRR, Barbosa ADS.An analysis was made of the frequency of Cryptosporidium spp. in fecal samples from horses raised on farms in the Teresópolis city, state of Rio de Janeiro, Brazil, and the risk factors that favored this infection. Between 2019 and 2020, 314 samples of equine feces were collected, 287 of which came from English Thoroughbred horses and 27 from ponies. Information on the horses and their management were retrieved from a stud book and forms filled out by trainers. The fecal samples were subjected to macroscopic analysis, modified Sheather's and Lutz parasitological techniques, safranin staining,...
Ahmadi Afshar N, Malekifard F, Asri Rezaei S, Tavassoli M.Equine piroplasmosis is a tick-borne protozoal disease affecting horses, mules, donkeys and zebras and can lead to severe economic losses in the equine industry. There is limited information on clinical pathologic changes of equine piroplasmosis in donkeys. This study aims to investigate the impacts of babesiosis on various hematological and biochemical properties in naturally infected donkeys with Theileria equi and Babesia caballi. Methods: A total of 200 apparently healthy donkeys were randomly examined for the presence of equine piroplasmosis in blood samples. Of 200 samples, 11(5.5%) anim...
Cruz I, Vinhas AR, Dubey JP, Cardoso L, Cotovio M, Lopes AP.Neospora spp. are intracellular protozoa with worldwide distribution and closely related to Toxoplasma gondii, which can infect a variety of mammals including horses. From September 2013 to June 2014, 185 horses from northern, central and southern parts of mainland Portugal were randomly sampled and tested for detection of immunoglobulin (Ig) G antibodies to Neospora spp. using an indirect multi-species enzyme-linked immunosorbent assay (ELISA) commercial test (ID Screen® Neospora caninum Indirect Multi-species; ID.vet Innovative Diagnostics, Grabels, France). Two horses (1.1%; CI: 0.1-3.8%),...
Peglar MT, Nerad TA, Anderson OR.A new species of lobosean amoeba, Stenamoeba polymorpha n. sp., was isolated from the diarrheic stool of a domesticated horse in Great Falls Virginia, U.S. It shares characteristics with the five other described Stenamoeba species. However, electron microscopy revealed S. polymorpha has a substantially thickened cell surface lamina. Under light microscopy, the amoebae had a dynamic polymorphic appearance because hyaloplasm readily formed and resorbed subpseudopodia from any peripheral region of the cell. While in locomotion, the amoebae produced subpseudopodia that led and alternated the dire...
Among the protozoa of the genus Sarcocystis (Apicomplexa; Sarcocystidae), Sarcocystis bertrami (syn. Sarcocystis fayeri) is an obligate intracellular parasite of donkeys and horses with worldwide distribution. Here, we report the detection of S. bertrami in naturally infected donkeys from southern Italy and describe their structure by light microscopy (LM) and transmission electron microscopy (TEM). Protozoal cysts were detected both morphologically and molecularly in skeletal muscles of 28.57% (40/140) donkeys. Mature cysts of S. bertrami were found in skeletal muscle measuring 31-102 μm l...
Lindsay DS, Dykstra CC, Williams A, Spencer JA, Lenz SD, Palma K, Dubey JP, Blagburn BL.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. A horse model of EPM is needed to test the efficacy of chemotherapeutic agents and potential vaccines. Five horses that were negative for antibodies to S. neurona in their serum and cerebrospinal fluid (CSF) were injected in the subarachnoid space with living merozoites of the SN2 isolate of S. neurona. None of the horses developed clinical disease or died over a 132-day observation period. All five horses develope...
Imai S, Ozeki K, Fujita J.The surface structure of the ciliary zone in 13 species of ciliates found in the large intestine of the horse was observed by scanning electron microscopy. In Holophryoides ovalis many fine depressions considered to be a result of phagocytosis or pinocytosis in the naked cytostome were noticed. In Blepharocorys spp. a distinct section was present between the portion with cilia and that without cilia. It was not present, however, in some species of the family Buetschliidae, such as Bundleia postciliata and Didesmis spp. The species of Entodiniomorphida had a lip around the ciliary zone with cil...
Yılgör Çırak V, Girişgin AO.Significant numbers of parasites such as protozoa, helminths and arthropods infest equids. Various investigations have been conducted in Turkey to detect these parasites. In this review, all parasites reported in horses, donkeys and mules have been listed. A total of 62, 52 and 21 helminths were recorded in horses, donkeys and mules, respectively. As protozoan parasites, 13 species were detected both in horses and donkeys, and 3 in mules. With regard to arthropods, 40, 23 and 6 species were detected in horses, donkeys and mules, respectively. In the recent years, various molecular diagnostic m...
Ren WX, Zhang XX, Long CY, Zhao Q, Cheng T, Ma JG, Xu P, Hou G, Ni HB.Horse meat and milk are an important source of nutrition for many Chinese. Previous studies have shown a fairly high prevalence of infection in horses. However, there is no data concerning the molecular characterization of in horses in China. The present study tested 231 cervical lymph node samples of horses from northern China (97 from Jilin, 54 from Liaoning, and 80 from Xinjiang) for the presence of the B1 gene by seminested PCR. The B1-positive samples were genotyped at nine nuclear loci, that is, SAG1, alternative SAG2, SAG3, BTUB, c22-8, GRA6, c29-2, PK1, and an apicoplast locus, usin...
Equine protozoal myeloencephalitis (EPM) is a neurological disease caused by Sarcocystis neurona. Immunofluorescence antibody tests (IFATs) have been widely used to identify exposure of horses to S. neurona in Brazil. Here we used IFAT to search for IgG antibodies against Sarcocystis falcatula-like (Dal-CG23) and S. neurona (SN138) in sera from 342 horses sampled in Campo Grande, Mato Grosso do Sul state (Midwestern), and São Paulo, São Paulo state (Southeastern), Brazil. The 1:25 cutoff value was chosen to maximize sensitivity of the test. IgG antibodies against S. neurona were detected in ...
Sengupta PP, Rudramurthy GR, Ligi M, Jacob SS, Rahman H, Roy P.Trypanosoma evansi, a haemoflagellated protozoan parasite, is responsible for chronic as well as the acute debilitating disease called surra in a wide range of herbivores and carnivores including domestic and wild animals. Since the parasite is having wide host range, there is a need for diagnostic test which can detect the T. evansi specific antibody in different species of animals for generating sero-surveillance data. In the present study we developed and evaluated competitive enzyme immunoassay using monoclonal antibodies (MAbs) raised against recombinant variable surface glycoprotein (rVS...
Gupta S, Vohra S, Sethi K, Gupta S, Kumar S, Kumar R.The kinetoplastid protozoan parasite, Trypanosoma evansi causes a fatal disease condition known as Surra in equines throughout the globe. Disease condition being acute in nature, entrust a huge economic and health impact on the equine industry. Till date, quinapyramine methyl sulphate (QPS) is the first line of treatment and a panacea for the T. evansi infection in equines. Still after the >70 years of its discovery, there is no clue about the mode of action of QPS in T. evansi. The establishment of in vitro cultivation of T. evansi in HMI-9 media has provided opportunity to study the alte...
Njoku CJ, Saville WJ, Reed SM, Oglesbee MJ, Rajala-Schultz PJ, Stich RW.Equine protozoal myeloencephalitis (EPM) is a disease of horses that is primarily associated with infection with the apicomplexan Sarcocystis neurona. Infection with this parasite alone is not sufficient to induce the disease, and the mechanism of neuropathogenesis associated with EPM has not been reported. Nitric oxide (NO) functions as a neurotransmitter, a vasodilator, and an immune effector and is produced in response to several parasitic protozoa. The purpose of this work was to determine if the concentration of NO metabolites (NO(x)(-)) in the cerebrospinal fluid (CSF) is correlated with...
Tanaka Y, Adilbish A, Koyama K, Bayasgalan MO, Horiuchi N, Uranbileg N, Watanabe K, Purevdorj B, Gurdorj S, Banzragch B, Badgar B, Suganuma K....Dourine is a deadly protozoan disease in equids caused by infection with Trypanosoma equiperdum. Neurological signs in the later stage of infection may be caused by peripheral polyneuritis and related axonal degeneration. This neuritis involves T lymphocytes, B lymphocytes, and macrophages, and is observed in cases without obvious neurological signs. However, the pathogenesis of neuritis remains unclear. We identified M2 macrophages and CD8 T cells as the predominant phenotypes in neuritis of dourine-affected horses with or without neurological signs. In contrast, the populations of M1 macroph...
Llano HAB, Soares RM, Acevedo-Gutierrez LY, Rodas JD, Polo G, Borges-Silva W, Jesus RF, Gondim LFP.Sarcocystis neurona and Neospora spp. are related protozoa that can cause equine protozoal myeloencephalitis (EPM). The present study aimed to determine the frequency of antibodies to these parasites in 649 equids (351 horses, 267 donkeys, and 31 mules) from six departments in the North and Northwest of Colombia. For this purpose, the indirect fluorescent antibody test (IFAT) was used for detecting antibodies against S. neurona and Neospora spp. with a cut-off point of 1:20 and 1:50, respectively. A binomial logistic regression model was selected to predict variables associated with exposure. ...
Bonhomme-Florentin A.Cecum microfauna association with different plant tissues was examined by scanning and transmission electron microscopy. The ciliates were attached to the damaged areas of the leaves and their highest concentrations were found on the epidermis and mesophyll tissues. The degradation of plant tissue was due to protozoal ingestion of the plant fragments. The morphology of ingested envacuolized chloroplasts changed rapidly, showing different stages of digestion inside the ciliate endoplasm. Intact chloroplasts were rarely observed but the grana of fragmented thylakoid membranes was often seen. The...
Chaney SB, Marsh AE, Lewis S, Carman M, Howe DK, Saville WJ, Reed SM.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 stu...
Sharma D, Gupta S, Sethi K, Kumar S, Kumar R.Trypanosoma evansi, a hemoflagellate protozoan parasite, causes wasting disease called surra in wide range of animals. Although the organism has been reported from various parts of India, data generated from organized epidemiological study is still in infancy in majority states of India. In the present study, livestock of Himachal Pradesh, India, was targeted for epidemiological investigation of T. evansi infections. A total of 440 equines and 444 cattle serum samples were collected from four agro-climatic zones. Furthermore, serum samples of 280 buffaloes from three different agro-climatic zo...
Bělková T, Bártová E, Řičařová D, Jahn P, Jandová V, Modrý D, Hrazdilová K, Sedlák K.Theileria equi and Babesia caballi are protozoan agents causing equine piroplasmosis, endemic in countries all over the world. The aim of this study was to detect antibodies to T. equi and B. caballi in horses in the Czech Republic and to investigate the origin of the infection. Blood sera from 711 horses were examined with competitive enzyme-linked immunosorbent assay; positive samples were verified with indirect fluorescence immunoassay. Antibodies to T. equi and B. caballi were detected in eight (1.1%) and three (0.4%) horses, respectively. Infection with T. equi was confirmed by PCR and se...
Yang G, Chen K, Guo W, Hu Z, Qi T, Liu D, Wang Y, Du C, Wang X.Equine piroplasmosis (EP) is a serious problem in the horse industry, and controlling EP is critical for international horse trading. EP is caused by two apicomplexan protozoan parasites, Theileria equi and Babesia caballi. Rapid and accurate methods that are suitable for detecting these parasites in the field are crucial to control the infection and spread of EP. In this study, we developed a card to detect antibodies against T. equi and B. caballi based on two colloidal gold immunochromatographic strips according to the principle of the double-antigen sandwich. The proteins equi merozoite an...
Equine piroplasmosis is a disease of equids, caused by tick-borne apicomplexan protozoan pathogens Babesia caballi and Theileria equi, which, according to the World Organisation for Animal Health (OIE), can be diagnosed by enzyme-linked immunosorbent assay (ELISA), immunofluorescent antibody test (IFAT) and polymerase chain reaction (PCR). The present study was conducted to evaluate and compare the assays available for the diagnosis of equine piroplasmosis. Data employed were obtained from 1300 blood samples collected between 2012-2014 from asymptomatic and symptomatic equines (horses and donk...
Lopes KFC, Delai RM, Fazoli KGZ, Rey LMR, Lopes-Mori FMR, Benitez ADN, Borges Neto A, Bernardes JC, Caldart ET, Mitsuka-Breganó R, Navarro IT....The presence of DNA and anti- spp. antibodies in the serum of 112 healthy horses was investigated by evaluating the physical examination, from a rural society located in the north central region of Paraná. The antigens of , , and were used to perform the indirect enzyme-linked immunosorbent assay, where it was possible to detect the reaction in 27.67% of the samples. These were also subjected to the real-time quantitative PCR, which confirmed the presence of spp. DNA in 67.34% of the tested samples. The results show that the tested animals were previously exposed to the protozoan. Thus, the...
Kamani J, Bártová E, Kašpárková N, Mohammed SJ, Budíková M, Sedlák K.The protozoan parasites Theileria equi and Babesia caballi, transmitted by ticks, cause equine piroplasmosis, the most prevalent tick-borne disease in equids. Trichinellosis is a worldwide food-borne zoonosis caused by helminth Trichinella spp. that can lead to serious disease in humans, with fatal outcome. Although the infection is rare in horses, it deserves attention due to the increasing use of horse meat as a source of protein for humans. Horse trichinellosis is caused by several Trichinella species, most commonly by T. spiralis. The aim of the study was to determine the prevalence of ant...
Rosypal AC, Lindsay DS, Duncan R, Ahmed SA, Zajac AM, Dubey JP.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. Little is known about the role of immunobiological mediators to this parasite. Nitric oxide (NO) is important in resistance to many intracellular parasites. We, therefore, investigated the role of inducible and endothelial NO in resistance to clinical disease caused by S. neurona in mice. Groups of interferon-gamma gene knockout (IFN-gamma-KO) mice, inducible nitric oxide synthase gene knockout (iNOS-KO) mice, endo...
Qamar W, Alsayeqh AF.Third-world countries have a higher prevalence of food-related disorders than developed nations. Millions of people in underdeveloped countries are seriously at risk from the potential water supply contamination with protozoan diseases. is one of the important protozoans causing diseases in livestock and humans. Despite the standard tests for diagnosing this parasite and different treatment methods, the spread of these parasites is uncontrollable and rising every year due to other management disorders. In this review, we summarize etiopathogenesis and prevalence in Pakistan. We looked for pap...
Mesafint E, Dejene H, Maru M, Tarekegn ZS.We performed this review to determine the weighted prevalence of equids parasitic infections in Ethiopia. Article searches on parasites of equids were conducted using PubMed, PubMed Central, Google Scholar, Science Direct, Web of Sciences, Scopus, AJOLs and Research Gate. A random effects model was used to estimate the weighted prevalence and to study heterogeneity. The primary searches generated, 3082 potential studies, of which 66 reports met the inclusion criteria and were included in the meta-analysis. There were 32 reports involving two or more equids species, eighteen on donkeys, and six...
