Polymerase Chain Reaction (PCR) is a molecular biology technique used to amplify specific DNA sequences, allowing for detailed genetic analysis in horses. This method enables the detection and quantification of genetic material, facilitating research in areas such as genetic disorders, infectious diseases, and population genetics in equine species. PCR applications in horses include identifying pathogens, verifying parentage, and studying genetic variations. The technique's sensitivity and specificity make it a valuable tool in equine veterinary diagnostics and research. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and advancements of PCR in equine science.
Burton AJ, Nydam DV, Dearen TK, Mitchell K, Bowman DD, Xiao L.To date, little is known about the prevalence, genotypes and zoonotic potential of Cryptosporidium spp. affecting horses, especially in North America. A cross-sectional study was conducted in New York, USA between February 25th and May 1st 2009. Fecal samples were collected from three hundred and forty nine 1-10-week-old foals and their dams on 14 different broodmare farms. All fecal samples were screened for Cryptosporidium spp. using a direct immunofluorescence assay (DFA). DNA extraction and PCR-RFLP analysis of the small-subunit (SSU) rRNA gene were performed on all the foal samples. PCR-p...
Bhoora R, Buss P, Guthrie AJ, Penzhorn BL, Collins NE.Seventy EDTA blood samples collected from plains zebra (Equus quagga burchellii) and Cape mountain zebra (Equus zebra zebra) were screened for the presence of piroplasm parasite DNA using quantitative T. equi-specific and B. caballi-specific TaqMan real-time PCR (qPCR) tests. T. equi parasite DNA was detected in 60 samples, 19 of which were also positive for B. caballi. Approximately 1480bp of the piroplasm 18S rRNA gene was amplified and sequenced from 17 samples, while the V4 hypervariable region of the 18S rRNA gene was amplified, cloned and sequenced from 31 samples. BLASTN analysis reveal...
Kydd JH, Slater J, Osterrieder N, Antczak DF, Lunn DP.This report summarises the findings of the Second Havemeyer EHV-1 Workshop, which was held in Steamboat Springs, Colorado, USA in September 2008. A total of 38 delegates, consisting of veterinary clinicians and scientists from academia and industry participated in a series of sessions that focused on equine herpesvirus myeloencephalopathy (EHM). Each session consisted of a review, followed by short presentations on current research topics. The sessions included EHM epidemiology, in vivo and in vitro models for studying EHM, EHV-1 virulence determinants, real-time PCR diagnostics, antiviral med...
Santos EM, Paula JF, Motta PM, Heinemann MB, Leite RC, Haddad JP, Del Puerto HL, Reis JK.We compared three different protocols for DNA extraction from horse peripheral blood mononuclear cells (PBMC) and lung fragments, determining average final DNA concentration, purity, percentage of PCR amplification using beta-actin, and cost. Thirty-four samples from PBMC, and 33 samples from lung fragments were submitted to DNA extraction by three different protocols. Protocol A consisted of a phenol-chloroform and isoamylic alcohol extraction, Protocol B used alkaline extraction with NaOH, and Protocol C used the DNAzol((R)) reagent kit. Protocol A was the best option for DNA extraction from...
Malik P, Pálfi V, Bálint A.Equine herpesvirus-1 (EHV-1) is a major pathogen of horses with worldwide distribution that can cause various clinical signs ranged from mild respiratory disease to neurological symptoms. Comparison of neuropathogenic and non-neuropathogenic EHV-1 strains revealed that a single non-synonymous nucleotide substitution (A/G2254) in the ORF30 region is associated with the altered functions of the viral DNA polymerase and therefore the neuropathogenicity of EHV-1 virus strains. The aim of the present study was the development of a new differentiation method of this particular single nucleotide poly...
Bogaert L, Heerden MV, Cock HE, Martens A, Chiers K.Ten equine skin tumors that had been classified as schwannomas on routine histological examination were analyzed by polymerase chain reaction for bovine papillomavirus DNA. All 10 were positive for bovine papillomavirus 1 or 2, and all 10 were immunohistochemically negative for S-100 protein and strongly positive for vimentin. Nine tumors were moderately positive for laminin and 8, for smooth muscle actin. Five tumors were variably and weakly positive for type IV collagen. The lack of S-100 protein expression made Schwann cells an unlikely cell of origin, as opposed to peripheral nerve sheath ...
Bolton T, Kuskie K, Halbert N, Chaffin K, Healy M, Lawhon S, Jackson A, Cohen N.Rhodococcus equi is an important pathogen of foals aged 1-6 months. Evidence exists that foals are exposed to a wide diversity of R. equi strains in their environment. However, limited data are available regarding the extent to which genotypic variation exists among isolates infecting individual foals. Therefore, electrophoresis of repetitive sequence-based polymerase chain reaction (rep-PCR) amplicons in an automated microfluidics chip format was used to genotype 9 virulent R. equi isolates obtained from distinct anatomic locations in a single foal. Four of the isolates were obtained from dif...
Spolidorio MG, Labruna MB, Machado RZ, Moraes-Filho J, Zago AM, Donatele DM, Pinheiro SR, Silveira I, Caliari KM, Yoshinari NH.Blood samples collected from 201 humans, 92 dogs, and 27 horses in the state of Espirito Santo, Brazil, were tested by polymerase chain reaction, indirect immunofluorescence assays, and indirect enzyme-linked immunosorbent assay for tick-borne diseases (rickettsiosis, ehrlichiosis, anaplasmosis, borreliosis, babesiosis). Our results indicated that the surveyed counties are endemic for spotted fever group rickettsiosis because sera from 70 (34.8%) humans, 7 (7.6%) dogs, and 7 (25.9%) horses were reactive to at least one of the six Rickettsia species tested. Although there was evidence of ehrlic...
Goehring LS, Landolt GA, Morley PS.Because of the serious disease sequelae associated with equine herpesvirus type 1 (EHV-1) infections, awareness and control measures used to control outbreaks are important issues for all horse populations. Objective: Describe the occurrence and management of an outbreak of EHV-1 infection at a veterinary hospital. Methods: Horses hospitalized at a referral veterinary hospital. Methods: A horse with myeloencephalopathy associated with EHV-1 infection (EHM) was admitted for diagnostic evaluation and treatment under strict infection control procedures. We describe the occurrence and management o...
Oslund KL, Adamson G, Wu R.To isolate and culture primary equine airway epithelial cells in vitro and elucidate the major cytokines involved in expression of the gel-forming mucin gene MUC5AC in horses. Methods: 12 tracheas obtained within 5 hours after euthanasia from horses free from respiratory tract disease. Methods: Tracheal rings were digested overnight in 0.2% protease, and dissociated airway epithelial cells were grown in a serum-free defined medium at an air-liquid interface until confluence was achieved. Differentiated airway epithelial cells were treated with a panel of recombinant equine cytokines followed b...
Easton C, Fuentealba NA, Paullier C, Alonzo P, Carluccio J, Galosi CM.Equine herpesvirus 1 (EHV-1) is a major cause of epidemic abortion, neonatal mortality, respiratory disease and neurological disorders in horses. In South America, the virus has been isolated in Brazil, Argentina and Colombia. In Chile pathological findings from one aborted foetus have been reported, and in Uruguay only serological data about EHV-1 activity have been found. Some pathological findings were reported in Uruguay several years ago, but these data have never been officially confirmed. The present work describes the relevant findings of a study of EHV-1 infections in the Uruguayan eq...
Shimizu C, Shibahara T, Takai S, Kasuya K, Chikuba T, Murakoshi N, Kobayashi H, Kubo M.A 26-month-old thoroughbred colt with a 4-month history of continuous diarrhoea and weight loss was subject to necropsy examination. The small intestinal mucosa was thickened and this change particularly affected the terminal ileum. Microscopical examination revealed multifocal epithelial hyperplasia, with multifocal granulomas and marked lymphocytic infiltration of the lamina propria. Numerous gram-negative argyrophilic curved bacilli were observed within the cytoplasm of affected enterocytes. Macrophages and epithelioid cells forming the granulomas had abundant, lightly eosinophilic, foamy c...
Blutke A, Hamel D, Hüttner M, Gehlen H, Romig T, Pfister K, Hermanns W.In Europe, cystic echinococcosis is rare in horses and is mostly diagnosed at slaughter or postmortem examination. Equine cystic echinococcosis can be caused by various Echinococcus taxa, but only Echinococcus equinus (the "horse strain") is known to produce fertile cysts. In Europe, E. equinus appears to be endemic in Great Britain, Ireland, Spain, and Italy and has sporadically been reported in Belgium and Switzerland. The present report describes the first case of a molecularly confirmed E. equinus infection in a horse foaled and raised in Germany. The 19-year-old mare was presented for exa...
Nemoto M, Hata H, Higuchi T, Imagawa H, Yamanaka T, Niwa H, Bannai H, Tsujimura K, Kondo T, Matsumura T.We evaluated antigen detection kits for human rotavirus with regard to their usefulness for diagnosing equine rotavirus infection. Limiting dilution analyses showed that of the seven kits investigated the Dipstick `Eiken' Rota (Dipstick) had the highest sensitivity to two serotypes of equine rotavirus. The Dipstick did not cross-react with several equine intestinal pathogens. An investigation using 249 fecal samples indicated that the sensitivity of the Dipstick was 81.9% and 47.3%, and its specificity was 98.2% and 99.0%, and its concordance rate was 92.8% and 68.3%, compared with values obta...
Bhoora R, Quan M, Matjila PT, Zweygarth E, Guthrie AJ, Collins NE.Although a quantitative real-time PCR assay (qPCR) assay for the detection of Theileria equi has been developed and evaluated, it is possible that additional, as yet undetected 18S rRNA gene sequence variants may exist. A qPCR assay targeting a different gene, used in conjunction with the T. equi 18S rRNA qPCR assay, could assist in the detection of all T. equi genotypes in field samples. A T. equi ema-1-specific qPCR (Ueti et al., 2003) was tested on 107 South African field samples, 90 of which tested positive for T. equi antibody using the immuno-fluorescent antibody test (IFAT). The qPCR as...
Dieckmann SM, Winkler M, Groebel K, Dieckmann MP, Hofmann-Lehmann R, Hoelzle K, Wittenbrink MM, Hoelzle LE.Haemotrophic mycoplasmas (HM) are parasites on the surface of red blood cells and known to infect a wide range of animals. However, there are no previous evidences of HM infections in horses. In this study HM were detected for the first time in the blood of two horses suffering from poor performance, apathy, weight loss, and anaemia. Using a HM specific PCR assay and subsequent sequencing the infective agents isolated from the blood of said horses were confirmed as closely related to the HM species Mycoplasma haemofelis and 'Candidatus Mycoplasma haemobos'.
Angelini P, Tamba M, Finarelli AC, Bellini R, Albieri A, Bonilauri P, Cavrini F, Dottori M, Gaibani P, Martini E, Mattivi A, Pierro AM, Rugna G....Following a large West Nile virus (WNV) epidemic in northeastern Italy in 2008, human and animal surveillance activities were implemented in Emilia Romagna. Human surveillance was performed by serology or genome detection on blood and cerebrospinal fluid for all suspected cases suffering from acute meningoencephalitis in the regional territory. Animal surveillance consisted of passive and active surveillance of horses and active surveillance of wild birds and mosquitoes. Between 15 June and 31 October 2009, nine of 78 possible cases of West Nile neuroinvasive disease were confirmed (three fata...
van Zyl A, Daniel J, Wayne J, McCowan C, Malik R, Jelfs P, Lavender CJ, Fyfe JA.Two horses were diagnosed as having Mycobacterium ulcerans infections. The first was a 21-year-old Quarterhorse-cross mare living in Mallacoota (a coastal town near the border of New South Wales and Victoria, Australia) that presented with lichenification, hair-loss and oedema on a fetlock, which subsequently ulcerated, as well as a non-healing ulcer on the wither. The second horse was a 32 year-old Standardbred gelding from Nicholson, near Bairnsdale, Victoria, that had an ulcerated lesion on its caudal thigh. Histologically, there were characteristic changes seen with M. ulcerans infections ...
Pronost S, Léon A, Legrand L, Fortier C, Miszczak F, Freymuth F, Fortier G.Equine herpesvirus 1 (EHV-1) is a common pathogen of the horse which may induce mild respiratory distress, abortion, neonatal death and neurological disease. A single nucleotide polymorphism in the EHV-1 DNA polymerase (ORF30 A(2254) to G(2254)) has been associated with clinical signs of Equine herpes myeloencephalopathy (EHM). The aim of this work was to analyze the ORF30 genomic region among a panel of EHV-1 DNA extract in order to estimate the prevalence of the EHV-1 neuropathogenic genotype in France. Samples coming from cases associated with EHM, horses with respiratory symptoms and abort...
Venugopal CS, Mendes LC, Peiró JR, Laborde SS, Stokes AM, Moore RM.To identify differentially expressed genes in pulmonary tissues of horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD), which is a form of recurrent airway obstruction (RAO), compared with those of unaffected horses. Methods: 6 horses with SPAOPD-RAO and 6 unaffected (healthy) horses. Methods: Horses were assigned to 2 groups on the basis of medical history, clinical score, and transpleural pressure. Total RNA from each of the 5 lung lobes of each of the 6 SPAOPD-RAO-affected horses was extracted and pooled. Similarly, total RNA from unaffected horses was pool...
Mienaltowski MJ, Huang L, Bathke AC, Stromberg AJ, MacLeod JN.Human and equine cell transplant strategies for cartilage lesions usually result in scar tissue that is similar to what is produced naturally during the repair process. In this study, culture-expanded de-differentiated chondrocytes and primary bone marrow stromal cells at a pre-transplantation time-point were compared along with neonatal cartilage to repair tissue. Transcriptional profiling using a 9413-probeset equine-specific cDNA microarray and targeted real-time quantitative polymerase chain reaction validation were used to characterize relationships between these cell types and repair tis...
Quan M, Lourens CW, MacLachlan NJ, Gardner IA, Guthrie AJ.Nucleotide sequences of 52 South African isolates of African horse sickness virus (AHSV) collected during 2004-2005 and including viruses of all nine AHSV serotypes, were used to design and develop a duplex real-time reverse transcription quantitative PCR (RT-PCR) assay targeting the VP7 (S8) and NS2 (S9) genes of AHSV. The assay was optimized for detection of AHSV in fresh and frozen blood of naturally infected horses. Assay performance was enhanced using random hexamers rather than gene-specific primers for RT, and with denaturation of double-stranded RNA in the presence of random hexamers. ...
Fritz D.Positive PCR results for piroplasms were obtained on EDTA blood samples from 166 dogs and 111 horses between March 2006 and March 2008. The organisms were initially identified using common primers, followed by restriction enzyme profiles to determine the species and types of Babesia/Theileria. In 27 dogs and eight horses with positive results, the size of the specimen was insufficient to separate species/types. We identified Babesia canis canis in 105 of the 166 dogs (63%) and Theileria equi in 89 of the 111 horses (80%). Babesia caballi was also present, but rare, in only two Babesia/Theileri...
Knowles EJ, Mair TS, Butcher N, Waller AS, Wood JL.Thirty horses with no external signs of strangles were tested for exposure to Streptococcus equi subspecies equi (S equi) using a new, commercially available serological test. The horses were also tested for persistent carriage of S equi by endoscopy of the guttural pouches and PCR analysis of lavage samples. The owners were questioned about the recent medical history of the horses. Serology suggested that four horses had been recently exposed to S equi. None of the horses had a known history of strangles but three of the four seropositive horses had recently shown non-specific signs of respir...
Merwyn S, Kumar S, Agarwal GS, Rai GP.Glanders is highly contagious disease of equines, caused by Burkholderia mallei. The disease though rare, can be transmitted to humans. Here, we report a strategy for rapid detection of B. mallei from environmental samples. Different bacteriological media were evaluated and brain heart infusion broth medium with selective supplements (BHIB-SS) of penicillin (200 U/ml) and crystal violet (1:10,00000) was found to support the maximum growth of B. mallei even in the presence of other bacteria like Escherichia coli and Staphylococcus aureus. A polymerase chain reaction (PCR) and a DNA hybridizatio...
Preziuso S, Laus F, Tejeda AR, Valente C, Cuteri V.Streptococcus (S.) dysgalactiae subsp. equisimilis is responsible for severe diseases in humans, including primary bacteraemia, pneumonia, endocarditis, and toxic shock syndrome. Infection in some animal species can also occur, although a few studies have looked into cross-species infectivity. In horses, S. equisimilis is generally considered infrequent or opportunistic, but has recently been isolated from cases of strangles-like disease. Rapid and sensitive diagnostic techniques could enable epidemiological studies and effective investigation of outbreaks involving these bacteria. In this stu...
Morita H, Nakano A, Shimazu M, Toh H, Nakajima F, Nagayama M, Hisamatsu S, Kato Y, Takagi M, Takami H, Akita H, Matsumoto M, Masaoka T, Murakami M.To detect the predominant lactobacilli in the intestinal flora of healthy thoroughbreds, we isolated lactobacilli from the feces of nine thoroughbreds (five males and four females; 0-15-year-old). The isolated lactobacilli comprise 17 species (37 strains), and they were classified into five groups: Lactobacillus salivarius (6 species), L. reuteri (6 species), Lactobacillus delbrueckii (3 species), L. buchneri (1 species) and L. vitulinus (1 species). On the basis of 16S rRNA gene sequences, we identified 3 other phylogenetic relatives belonging to the genus Lactobacillus. These results suggest...
Pitel PH, Pronost S, Scrive T, Léon A, Richard E, Fortier G.Equine piroplasmosis is a tick-borne disease, the aetiological agents of which are either Theileria equi or Babesia caballi parasites. Piroplasmosis is commonly encountered in acute or sub-acute clinical forms although clinically recovered horses may remain asymptomatic but infected for several years. The clinical detection of such apparently healthy carrier horses (that serve as a host for subsequent infecting ticks), remains a worldwide challenge for controlling the spread of the disease. The aim of the present paper is to report on the detection of both T. equi and B. caballi by PCR in the ...
Nemoto M, Tsujimura K, Yamanaka T, Kondo T, Matsumura T.Loop-mediated isothermal amplification (LAMP) is a novel method for the rapid and sensitive detection of DNA without the need for expensive equipment. In the present study, LAMP assays were developed for the specific detection of Equid herpesvirus 1 and 4 (EHV-1 and EHV-4, respectively) and for the differentiation of glycoprotein E (gE)-deleted EHV-1 (DeltagE) strain, a candidate strain for a live vaccine, from field EHV-1 strains. Specific primer sets were designed for the gC and gE genes of EHV-1 and for the gC gene of EHV-4. The analytical sensitivities of the LAMP assays were compared with...
Brum MC, Anjos BL, Nogueira CE, Amaral LA, Weiblen R, Flores EF.An outbreak of severe cutaneous disease associated with an orthopoxvirus in horses in southern Brazil is described. Fourteen Crioulo mares and foals from a husbandry farm developed papules, and vesicles progressing to proliferative and exudative lesions on the muzzle, external nares, and external and internal lips. The vesicles eroded, and the proliferative lesions eventually bled and progressed to moist crusts and scars. The clinical signs lasted approximately 6-12 days, after which the animals progressively recovered. Direct electron microscopy of skin biopsies revealed brick-shaped, 250-300...
Schrenzel MD, Ferrick DA.Horse (Equus caballus) T-cell receptor alpha (TCRA), gamma (TCRG), and delta (TCRD) chain genes were isolated from a cDNA library and characterized. Five unique TCRAV families, including four full-length sequences, five distinct TCRAJ genes, and a single TCRAC gene were identified. TCRAV genes had closest homology with human sequences and least similarity to rat genes. Among eight horse TCRG genes, two distinct constant region genes with considerable variation in the connecting region were identified, but no variable or joining genes were present. Southern blot hybridization confirmed the pres...
Smith KC, McGladdery AJ, Binns MM, Mumford JA.To evaluate transabdominal ultrasound-guided amniocentesis for detection of equid herpes-virus 1 (EHV-1)-induced fetal infection in utero. Methods: 4 Welsh Mountain mares. Methods: Pregnant mares were inoculated intranasally with EHV-1 during the ninth month of gestation. Amniocentesis was initiated on postinoculation day (PID) 12, and was performed at 2- to 3-day intervals in standing mares under deep sedation. Amniotic fluid samples were tested by virus isolation (VI), polymerase chain reaction (PCR), and immunoperoxidase cytologic examination (IC) for detection of EHV-1. Results: Exposure t...
Hifumi T, Tanaka T, Hernandez EP, Akioka K, Yamada K, Imamura Y, Hatai H, Miyoshi N.Histopathological and genetic examinations were conducted on grayish-white solid hepatic nodules in 150 horses imported from Canada, in order to investigate larval Echinococcus multilocularis infection. Ten of the 150 horses (6.7%) were diagnosed with alveolar hydatid disease. The sequences of the mitochondrial cytochrome b genes obtained from all 10 polymerase chain reaction positive samples had 99 to 100% identity with the European haplotype E1 of E. multilocularis. Therefore, we concluded that the infections likely originated in Canada. Relation entre les nodules hépatiques solides blanc-g...
Kleiboeker SB, Turnquist SE, Johnson PJ, Kreeger JM.In previous studies, novel putative viral pathogens designated that asinine herpesvirus 4 (AsHV4) and asinine herpesvirus 5 (AsHV5) were associated with fatal interstitial pneumonia in donkeys (Equus asinus). Nucleotide sequence analysis of a portion of the DNA polymerase gene identified these putative pathogens as herpesviruses and possibly as members of the Gammaherpesvirinae subfamily. Although similar to equine herpesvirus 2 (EHV2) and equine herpesvirus 5 (EHV5), sequence diversity was observed among the detected viruses. In this study, novel sequence is reported for a DNA-packaging prote...
Malik P, Pálfi V, Bálint A.Equine herpesvirus-1 (EHV-1) is a major pathogen of horses with worldwide distribution that can cause various clinical signs ranged from mild respiratory disease to neurological symptoms. Comparison of neuropathogenic and non-neuropathogenic EHV-1 strains revealed that a single non-synonymous nucleotide substitution (A/G2254) in the ORF30 region is associated with the altered functions of the viral DNA polymerase and therefore the neuropathogenicity of EHV-1 virus strains. The aim of the present study was the development of a new differentiation method of this particular single nucleotide poly...
Pratscher B, Hainisch EK, Sykora S, Brandt S, Jindra C.There is a large body of evidence supporting bovine papillomavirus types 1 and 2 (BPV1; BPV2) as aetiological agents of equine sarcoids. However, there is conflicting data regarding BPV1/2 infection in sarcoid-free equids. Objective: Data obtained between 2007 and 2017 by BPV1/2 screening of sarcoids and nonsarcoid tumours vs. samples from healthy equids are presented to help clarify this issue. Methods: Cross-sectional study. Methods: Tumour material obtained from horses, donkeys and mules with confirmed sarcoids (n = 130), suspected sarcoids (n = 120), or nonsarcoid lesions (n = 70), s...
da Silveira BP, Gressler LT, Cargnelutti JF, Bordin AI, de Vargas AC.The ability of Rhodococcus equi to survive in macrophages and cause pneumonia in foals depends on vapA and rhbC genes, which produce the virulence-associated protein A (VapA) and the rhequichelin siderophore, respectively. Virulent R. equi acquires Fe from transferrin by unknown mechanisms. Our objectives were to determine the role of GAPDH in Fe homeostasis, to further characterize GAPDH, rhbC, and vapA expression under iron homeostasis, and to document the occurrence of rhbC gene in R. equi isolates. Therefore, vapA + R. equi was cultured under excessive, physiologic, and restricted iron c...
Grünig G, Antczak DF.The distribution of four cytokines was analyzed in the endometrium and trophoblast of the horse between Days 30 and 55 of gestation. Endometrial tissues, invasive trophoblast (chorionic girdle), and noninvasive trophoblast (chorion and allantochorion) were examined separately. Cytokine expression was determined by amplification of specific mRNA via the reverse transcriptase polymerase chain reaction (RT-PCR). Messenger RNA for interleukin 2 (IL-2), interleukin 4 (IL-4), and interferon gamma (IFN gamma) was detected in endometrial tissues, unstimulated peripheral blood lymphocytes, and control ...
Zientara S, Sailleau C, Moulay S, Wade-Evans A, Cruciere C.The development of a coupled reverse transcriptase-polymerase chain reaction assay (RT-PCR) is described for the detection of African horse sickness virus (AHSV) double-stranded RNA. Genome segments 7 and 10 were chosen as target templates for primers selected for use in the RT-PCR. Using these AHSV-specific primers all 9 serotypes were detectable. The sensitivity and specificity of the RT-PCR results were compared to those obtained by competition ELISA.
Kleiboeker SB, Loiacono CM, Rottinghaus A, Pue HL, Johnson GC.The North American West Nile virus (WNV) epizootic, which began in 1999, has caused significant morbidity and mortality in horses. Because experimental infection has failed to consistently produce encephalitis in inoculated horses, investigation of naturally occurring cases was used to optimize strategies for diagnosis of this disease. Although WNV RNA could be detected by reverse transcriptase-polymerase chain reaction (RT-PCR) performed on whole blood collected from both clinically affected horses and unaffected herdmates, the diagnostic sensitivity of this approach was low compared with IgM...
Sarradell JE, Alvarez J, Biscia M, Zumarraga M, Wunschmann A, Armien AG, Perez AM.A 2-year-old dappled Percheron horse had a wasting condition that did not respond to antibiotic treatments and ultimately resulted in death. Thickening of the wall of the large colon and enlargement of the mesenteric lymph nodes were observed at postmortem examination, along with the presence of pinpoint whitish foci in the liver. Microscopic examination of affected tissues revealed diffuse chronic granulomatous enterocolitis, granulomatous mesenteric lymphadenitis, and multifocal granulomatous hepatitis. The DNA extracted from paraffin-embedded intestinal and lymph node samples was analyzed u...
Lee E, Kim EJ, Shin YK, Song JY.The avian influenza A virus causes respiratory infections in animal species. It can undergo genomic recombination with newly obtained genetic material through an interspecies transmission. However, the process is an unpredictable event, making it difficult to predict the emergence of a new pandemic virus and distinguish its origin, especially when the virus is the result of multiple infections. Therefore, identifying a novel influenza is entirely dependent on sequencing its whole genome. Occasionally, however, it can be time-consuming, costly, and labor-intensive when sequencing many influenza...
Cursino AE, Lima MT, Nogueira MF, de Aguiar DM, Franco Luiz APM, Alves PA, Araujo Junior JP, Kroon EG.The aetiological agent of equine infectious anaemia (EIA) is the retrovirus equine infectious anemia virus (EIAV) that infects all members of the Equidae family. The EIA is widely disseminated in the Brazilian territory with a high seroprevalence in the Brazilian Pantanal and is mainly diagnosed using agar gel immunodiffusion (AGID). There are few complete EIAV genome sequences available in GenBank, which had an impact on molecular detection studies. In this study, we conducted molecular detection and sequencing of EIAV proviral DNA from Brazilian horses. We analysed the genomic region from ex...
Watts MR, Hegedus OC, Eades SC, Belknap JK, Burns TA.Hyperinsulinemia is associated with equine laminitis, and digital lamellar inflammation in equine metabolic syndrome-associated laminitis (EMSAL) is modest when compared with sepsis-associated laminitis. Objective: To characterize digital lamellar inflammation in horses in a euglycemic-hyperinsulinemic clamp (EHC) model of laminitis. Methods: Sixteen healthy adult Standardbred horses. Methods: Prospective experimental study. Horses underwent EHC or saline infusion (CON) for 48 hours or until the onset of Obel grade 1 laminitis. Horses were euthanized, and digital lamellar tissue was collecte...
Clausen PH, Gebreselassie G, Abditcho S, Mehlitz D, Staak C.A field study of horses was conducted in the province of Bale, Ethiopian highlands. A rapid questionnaire analysis indicated that dourine, known as "Dirressa", is a major health problem of equines in this area. A total of 121 horses suspected of dourine were examined by use of clinical, parasitological, serological and DNA based techniques. Incoordination of hindlegs (76%), swelling of external genitalia (48.8%) and emaciation (39.7%) were the most common clinical signs observed. Using the haematocrit centrifugation technique (HCT), no trypanosomes were detected in blood, genital washes or tis...
Beckelmann J, Budik S, Bartel C, Aurich C.Until now, sex determination in equine embryos has been performed by detection of Y-chromosome-specific sequences only. In the present study, expression of a Barr-body-specific marker, the X-inactivated-specific transcript (Xist) gene, whose gene product consists of RNA which coats and thereby inactivates one of the X chromosomes, was investigated in equine embryos produced in vivo. Preattachment embryos at different times after ovulation (Day 8: n = 9; Day 10: n = 12; Day 12: n = 15) were analyzed for Xist RNA expression using quantitative and qualitative reverse transcription-polymerase chai...
Bullock PM, Ames TR, Robinson RA, Greig B, Mellencamp MA, Dumler JS.Equine granulocytic ehrlichiosis (EGE) is caused by infection with Ehrlichia equi. EGE has been reported primarily in northern California, where E equi is transmitted by the tick Ixodes pacificus. Reports of EGE and the emergence of human granulocytic ehrlichia in Minnesota prompted a seroprevalence study of E equi in horses of Minnesota and Wisconsin. Tick (Ixodes scapularis) endemic areas of Minnesota and Wisconsin were compared to nonendemic regions of Minnesota. Indirect fluorescent antibody was used to detect the presence of serum antibodies to E equi. Serum samples from healthy horses, 3...
Fitzgibbon JE, Sagripanti JL.The development of a method in macroarray format for the identification of alphaviruses and orthopoxviruses in samples of concern in biodefense is reported. Capture oligonucleotides designed to bind generic members of the orthopox- or alphavirus families and a collection of additional oligonucleotides to bind specifically nucleic acids from five individual alphaviruses, including Venezuelan equine encephalitis, or DNA from each of four orthopoxviruses, including variola virus (VAR) were deposited onto nylon membranes. Hybridization of digoxigenin labeled PCR products to the macroarray produced...
Villegas-Castagnasso EE, Díaz S, Giovambattista G, Dulout FN, Peral-García P.The second exon of equine leucocyte antigen (ELA)-DQB genes was amplified from genomic DNA of 32 Argentine Creole horses by PCR. Amplified DNA was analysed by PCR-restriction fragment length polymorphism (RFLP) and PCR-single-strand conformation polymorphism (SSCP). The PCR-RFLP analysis revealed two HaeIII patterns, four RsaI patterns, five MspI patterns and two HinfI patterns. EcoRI showed no variation in the analysed sample. Additional patterns that did not account for known exon 2 DNA sequences were observed, suggesting the existence of novel ELA-DQB alleles. PCR-SSCP analysis exhibited se...
Daly P, Doyle S.Equine herpesvirus-1 (EHV-1) infection is of significant animal welfare and economic importance. Yet, no standardised molecular techniques are available for diagnosis or confirmation of viral infection. The purpose of this study was to develop a standardised and quantitative assay system for the reliable detection of EHV-1 infection which was capable of eliminating the likelihood of false negative results. A region within the EHV-1 glycoprotein B gene was amplified by polymerase chain reaction (PCR), cloned and subjected to site-directed mutagenesis to generate a control plasmid, amplifiable b...
Elzinga SE, Rohleder B, Schanbacher B, McQuerry K, Barker VD, Adams AA.Extracts derived from the leaves of the stevia plant (stevioside) are commonly used as sweeteners for humans and horses. Stevioside appears to be safe for human consumption, including for individuals with insulin dysregulation. In the horse, the safety or metabolic effects of stevioside on normal animals or on those with metabolic dysfunction are unknown. Furthermore, the inflammatory response to a glycemic challenge or to stevioside in horses is not well defined. Therefore, the objective of this study was to measure the effects of stevioside and a glycemic challenge on insulin, glucose, and i...
Gomez DE, Wong D, MacNicol J, Dembek K.The fecal bacterial microbiota of normal foals and foals with enterocolitis has been characterized using next-generation sequencing technology; however, there are no reports investigating the gut microbiota in foals hospitalized for other perinatal diseases. Objective: To describe and compare the fecal bacterial microbiota in healthy and sick foals using next-generation sequencing techniques. Methods: Hospitalized (17) and healthy foals (21). Methods: Case-control study. Fecal samples were collected from healthy and sick foals on admission. Sick foals were further divided into sick nonseptic (...
Hermans LM, Bonsergent C, Josson A, Rocafort-Ferrer G, Le Guyader M, Angelloz-Pessey S, Leblond A, Malandrin L.Equine piroplasmosis is a tick-borne disease mainly caused by Theileria equi and Babesia caballi. The objectives of this study were to analyse the frequency and routes of vertical transmission of these blood parasites from 179 asymptomatic mares to their foals. Foals were sampled within 72 h post-partum. The seroprevalences determined by Indirect Immunofluorescent Antibody Test (IFAT) and based on a subset sample of 107 couples, were 59.8% and 42.1% for T. equi and B. caballi, respectively in the mare population, and 54.2% and 40.2% in the foal population. A species-specific nested PCR was per...
Ropka-Molik K, Stefaniuk-Szmukier M, Szmatoła T, Piórkowska K, Bugno-Poniewierska M.Arabian horses are commonly believed to be one of the oldest and the most popular horse breeds in the world, characterized by favourable stamina traits and exercise phenotypes. During intensive training, the rates of lactate production and utilization are critical to avoid muscle fatigue and a decrease in exercise performance. The key factor determining transmembrane lactate transport is the monocarboxylate transporter 1 protein coded for by the SLC16A1 gene. The aim of the present research was to identify polymorphisms in the coding sequence and UTRs in the equine SLC16A1 gene and to evaluate...
Borst LB, Patterson SK, Lanka S, Barger AM, Fredrickson RL, Maddox CW.To evaluate a commercially available modified-live Streptococcus equi subsp equi vaccine for safety and persistence in vaccinated ponies and to detect recombination or reversion events in the vaccine strain. Methods: 5 ponies that were 1.5 to 8 years old (group 1) and 4 ponies that were 6 months old (group 2). Methods: Ponies were vaccinated, with a subsequent booster vaccination 2 to 3 weeks later, and monitored for 50 days. At booster vaccination, an equal amount of a tetracycline-resistant wild-type strain of S equiwas administered. Recovery of all strains was performed by use of bacteriolo...
Huang J, Hartley CA, Ficorilli NP, Crabb BS, Studdert MJ.Glycoprotein G (gG) deletion mutants of EHV1 and EHV4, designated EHV1DeltagG and EHV4DeltagG, were constructed. The growth characteristics of the EHV1DeltagG mutants were similar to the parent virus. All of the EHV4DeltagG mutants grew more slowly in cell culture and produced plaques of different morphology including smaller size. The yields of both gG deletion mutant viruses in cell culture were similar to the parent viruses. Sequencing of the genes flanking gG, Southern blot, PCR and western blot analyses of the mutant viruses demonstrated that the deletions were as expected, except for EHV...
de Sousa SH, Paludo GR, Freschi CR, Machado RZ, de Castro MB.The aim of this report was to confirm the cause of abortion to be Theileria equi acquired transplacentally in a mare in Federal District, Brazil. The aborted fetus showed a high parasitemia of erythrocytes (80%) by the oval and Maltese cross forms of T. equi. Necropsy of the fetus demonstrated congestion of organs, jaundice, anemia and pronounced spleno- and hepatomegaly. Twelve breeding mares, including the one that aborted and her fetus, tested positive for T. equi infection by universal and multiplex PCR assay. The absence of histopathologic changes such as inflammation and necrosis in the ...
Fielding CL, Rhodes DM, Howard EJ, Mayer JR.OBJECTIVE To identify clinical or clinicopathologic variables that can be used to predict a positive PCR assay result for Anaplasma phagocytophilum infection in equids. ANIMALS 162 equids. PROCEDURES Medical records were reviewed to identify equids that underwent testing for evidence of A phagocytophilum infection by PCR assay between June 1, 2007, and December 31, 2015. For each equid that tested positive (case equid), 2 time-matched equids that tested negative for the organism (control equids) were identified. Data collected included age, sex, breed, geographic location (residence at the tim...
Palmero J, Pusterla N, Cherry NA, Kasten RW, Mapes S, Boulouis HJ, Breitschwerdt EB, Chomel BB.Experimental infection of horses with Bartonella species is not documented. Objective: Determine clinical signs, hematologic changes, duration of bacteremia, and pattern of seroconversion in Bartonella henselae or Bartonella bovis-inoculated horses. Methods: Twelve (2 groups of 6) randomly selected healthy adult horses seronegative and culture negative for Bartonella spp. Methods: Experimental/observational study: Group I: B. henselae or saline control was inoculated intradermally into 4 naïve and 2 sentinel horses, respectively. Group II: same design was followed by means of B. bovis. Daily ...
