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.
Anwaar F, Ijaz M, Rasheed H, Shah SFA, Haider SAR, Sabir MJ.The purpose of the current study was to investigate the nasal colonization and drug resistance profile of Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and vancomycin-resistant S. aureus (VRSA) in donkeys (n =63), mules (n = 42), and horses (n = 98). MRSA and VRSA were confirmed based on phenotypic and molecular methods, followed by phylogenetic analysis. Furthermore, the association of various animal and management-based risk factors with S. aureus colonization was also evaluated. The presence of nuc gene on polymerase chain reaction showed an overall prevalence of 42.86%...
Wong KS, Cheung HW, Szeto CWL, Tsang CYN, Wan TSM, Ho ENM.Illicit administration of transgene into horses is a form of gene doping that has been a key concern in equine sports. The large number of potential performance-enhancing transgenes has demanded a cost-effective and reliable detection method. Multiplex qPCR is a relevant technique, but the cross-talking between fluorophores and high background noise limits the method sensitivity and specificity. This study reports a simpler multiplexing approach by using the same fluorophore for four hydrolysis probes each targeting one of the four transgenes: human growth hormone, insulin-like growth factor 1...
Suniga PAP, Mantovani C, Santos MG, Rieger JSG, Gaspar EB, Dos Santos FL, Mota RA, Chaves KP, Egito AA, Filho JCO, Nassar AFC, Dos Santos LR....Glanders is a contagious disease of equids caused by the Gram-negative bacterium Burkholderia mallei. In Brazil, the disease is considered to be reemerging and has been expanding, with records of equids with positive serology in most of the federative units. However, there are few reports describing the genotypic detection of the agent. This study demonstrated the detection of B. mallei by species-specific PCR directly from tissues or from bacterial cultures, followed by amplicon sequencing in equids (equines, mules, and asinines) with positive serology for glanders in all five geographic regi...
Kamyingkird K, Choocherd S, Chimnoi W, Klinkaew N, Kengradomkij C, Phoosangwalthong P, Thammasonthijarern N, Pattanatanang K, Inpankaew T, Phasuk J....African horse sickness (AHS) was reported as an outbreak in Thailand in 2020. Hematophagous insects from the genus Culicoides are the suspected vector responsible for AHS transmission. Horses in Hua Hin district, Prachuab Khiri Khan province, Thailand, were affected and died from AHS in 2020. However, the potential Culicoides species and its host preference blood meal in the affected areas are unknown. To investigate the potential vectors of AHS, Culicoides were collected using ultraviolet light traps placed near horse stables. Six horse farms, including five farms with AHS history and one far...
Golombieski L, Bassi das Neves G, Casa MDS, Costa GCS, Miletti LC, Saito ME, Fonteque JH.Campeiro horse is a breed locally adapted to the Santa Catarina plateau region and its main characteristic is the gait, it is known as "Marchador das Araucárias." It is a breed considered in danger of extinction, being fundamental the search for the preservation of this important genetic resource. Surra, caused by the protozoan Trypanosoma evansi, is among the diseases that affect horses. However, there are no data on the prevalence of infection in Campeiro horses. This study aimed to determine the prevalence of T. evansi in Campeiro horses, correlate hematology and serum biochemistry, and id...
Mawhinney I, Bollard A.Detection of Taylorella equigenitalis (CEMO) in the horse uses genital swabs. These swabs traditionally have been put in Amies charcoal transport medium for detection by culture but are also used for PCR. We determined the suitability of swabs without transport medium (Dry swabs) for CEMO PCR compared to swabs in Amies charcoal transport medium. The experiment was a factorial design using swab type and dilution of organism in culture suspensions, done in two parts. Simulated genital swabs were prepared in the laboratory by dipping in pairs into culture suspensions containing T. equigenitalis w...
Rissi DR, Avery AC, Burnett RC.T-cell-rich, large B-cell lymphoma (TCRLBCL) is the most commonly diagnosed type of lymphoma in horses. Here we describe the clinical signs, neuropathology, immunohistochemistry (IHC), and PCR for antigen receptor rearrangement (PARR) analysis results of a TCRLBCL in the brain of an 8-y-old male Quarter Horse that was euthanized after acute anorexia, tremors, head pressing, falling, blindness, incoordination, and seizures. Autopsy revealed a firm, smooth, pale-yellow mass that expanded both lateral ventricles and the adjacent subcortical white matter. Histologically, the mass consisted of a de...
Chhabra D, Bhatia T, Goutam U, Manuja A, Kumar B.Strangles, caused by Streptococcus equi subspecies equi, is a highly infectious respiratory disease affecting horses and other equines. The disease is economically important and compromises the productivity of equine farm significantly. The disease is characterized by pyrexia, mucopurulent nasal discharge, and abscess formation in the lymph nodes of the head and neck of horses. The disease transmission occurs either directly by coming in contact with infectious exudates or indirectly via fomite transmission. Besides this, carrier animals are the primary and most problematic source of disease i...
Hifumi T, Tanaka T, Sato M, Akioka K, Fujimata C, Miyoshi N.Alveolar echinococcosis in slaughtered horses remains a public health issue. This study aimed to develop a Recombinase polymerase amplification (RPA) assay targeting the mitochondrial NADH dehydrogenase subunit 5 () gene of for the rapid detection of equine alveolar echinococcosis. Thirty-six hepatic solid nodules obtained from each horse ( = 36) were evaluated based on histopathological examination and -targeted PCR and then submitted to the RPA assay. The results of the developed RPA assay were 94.4% consistent with those of PCR and Cohen's kappa coefficient value was 0.89 statistically,...
Verhaar N, de Buhr N, von Köckritz-Blickwede M, Dümmer K, Hewicker-Trautwein M, Pfarrer C, Dengler F, Kästner S.Hypoxia inducible factors (HIF) are widely researched in human medicine for their role in different disease processes. The aim of this study was to investigate the expression and distribution of HIF in experimental small intestinal ischemia in the horse. Unassigned: In 14 horses under general anesthesia, segmental jejunal ischemia with 90% reduction in blood flow was induced. The horses were randomly divided into two groups of seven horses, one subjected to ischemic postconditioning (IPoC) by delayed reperfusion, and a control group (group C) undergoing undelayed reperfusion. Intestinal sample...
Baker E, Geick A, Hines M, Gerhold R, Cordero-Aponte C.A 17-year-old female grade pony presented to University of Tennessee Veterinary Medical Center in May of 2021 for evaluation of multifocal, firm, sessile, circular lesions of various diameters on the ventrum and flank. The lesions had been present for two weeks at presentation. An excisional biopsy found numerous adult and larval rhabditid nematodes most consistent with Halicephalobus gingivalis. PCR targeting a portion of the large ribosomal subunit confirmed this diagnosis. The patient was treated with a high dose course of ivermectin followed by fenbendazole. The patient began showing neuro...
Oliver A, Conrado FO, Nolen-Walston R.Equine granulocytic anaplasmosis is a clinically significant and common disease of equids that has a broader prevalence than was once thought. The most common clinical signs include high fever and edema, with mild to mderate thrombocytopenia and lymphopenia typically noted on complete blood count. Subclinical cases are reported and many are self-limiting. Rare clinical presentations include neurologic disease, vasculitis, dysphagia, rhabdomyolysis, or bicavitary effusion. Most cases resolve rapidly with appropriate antimicrobial intervention.
Ahedor B, Sivakumar T, Valinotti MFR, Otgonsuren D, Yokoyama N, Acosta TJ.Equine piroplasmosis (EP) is a tick-borne disease caused by Theileria equi and Babesia caballi in equids, including horses. EP has a global distribution and often leads to a significant socioeconomic impact on the equine industry. Infected animals remain as carriers and become a source of infection for tick vectors, thereby posing an immense challenge in the disease management. Therefore, detection of these carriers is crucial to assess the risk of transmission and to implement appropriate control measures in endemic countries. Paraguay is a tropical country where various tick-borne diseases a...
Miglinci L, Reicher P, Nell B, Koch M, Jindra C, Brandt S.Squamous cell carcinoma (SCC) seriously compromises the health and welfare of affected horses. Although robust evidence points to equine papillomavirus type 2 (EcPV2) causing genital lesions, the etiopathogenesis of equine SCC is still poorly understood. We screened a series of SCCs from the head-and-neck (HN), (peri-)ocular and genital region, and site-matched controls for the presence of EcPV2-5 and herpesvirus DNA using type-specific EcPV PCR, and consensus nested herpesvirus PCR followed by sequencing. EcPV2 DNA was detected in 45.5% of HN lesions, 8.3% of (peri-)ocular SCCs, and 100% of g...
Jaramillo-Morales C, James K, Barnum S, Vaala W, Chappell DE, Schneider C, Craig B, Bain F, Barnett DC, Gaughan E, Pusterla N.This study aimed to describe selected epidemiological aspects of horses with acute onset of fever and respiratory signs testing qPCR-positive for and to determine the effect of vaccination against on qPCR status. Horses with acute onset of fever and respiratory signs from all regions of the United States were included in a voluntary biosurveillance program from 2008 to 2020 and nasal secretions were tested via qPCR for and common respiratory viruses. A total of 715/9409 equids (7.6%) tested qPCR-positive for , with 226 horses showing coinfections with EIV, EHV-1, EHV-4, and ERBV. The median...
Munday JS, Grant K, Orbell G, Vaatstra BL.A 6-year-old Thoroughbred mare developed multiple flat plaques, < 1 cm in diameter, on the left front fetlock. These were treated topically using 5-fluorouracil and resolved after 4 weeks. However, additional similar plaques developed on the left front pastern 5 months later. These lesions resolved within 3 months without treatment. Unassigned: One plaque that developed initially and one plaque that developed later were examined histologically. Both consisted of well-demarcated foci of moderate epidermal hyperplasia. Scattered throughout both plaques were cells showing evidence of papillo...
Martineau M, Castagnet S, Kokabi E, Tricot A, Jaÿ M, Léon A, Tardy F.Bacteria belonging to the genus Mycoplasma are small-sized, have no cell walls and small genomes. They commonly cause respiratory disorders in their animal hosts. Three species have been found in the respiratory tract of horses worldwide, that is., Mycoplasma (M.) equirhinis, M. pulmonis and M. felis, but their role in clinical cases remains unclear. Objective: The aim of this study was to i) develop and validate tools to detect, isolate and identify different Mycoplasma spp. strains in clinical equine respiratory-tract specimens and ii) subsequently define the prevalence of the three species ...
Paraschou G, Cook JM, Priestnall SL, Evans NJ, Staton GJ, Paterson GK, Winkler B, Whitbread TJ.Keratoma is an aberrant keratin mass thought to originate from epidermal horn-producing cells interposed between the stratum medium of the hoof wall and the underlying third phalanx. The cause is unknown, although the presence of keratomas is frequently associated with chronic irritation, focal infection, or trauma. A total of 167 donkeys with keratomas were presented in this study. The diagnosis of a keratoma was based on clinical signs, radiography, and histopathologic examination. Surgical excision was attempted on all donkeys with lameness unless euthanasia was advised. Histopathologic exa...
Garner C, Stephen C, Pant SD, Ghorashi SA.Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is one of the causative agents of equine endometritis. In this study, a panel of different bacterial species, and colonies derived from bacteriological cultures of 38 clinical samples, were subjected to Loop-Mediated Isothermal Amplification (LAMP) assay and PCR, followed by high-resolution melt (HRM) curve analysis. All clinical samples were genotyped into three distinct groups based on HRM curve analysis. Differences in melting curve profiles were a reflection of DNA variation in sorD gene which was confirmed by DNA sequencing. A mat...
Bonilla-Aldana DK, Castaño-Betancourt KJ, Ortega-Martínez JM, Ulloque-Badaracco JR, Hernandez-Bustamante EA, Benites-Zapata VA, Rodriguez-Morales AJ.In a broad sense, are a group of microorganisms that can be transmitted mechanically or biologically to animals and humans. Rickettsioses are associated with hematic manifestations. Its prevalence in humans, dogs and other animals has been widely explored, but not in equine species. To determine the prevalence of infection in horses. A systematic review of the literature was carried out in five databases for the proportion of horses infected with , defined by molecular and immunological techniques. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence ...
Lohmann KL, Sieg M, Landmann M, Ganzenberg S, Arnold C, Vahlenkamp T, Ulrich RG.The presenting complaints, clinical signs, diagnostic evaluation, therapy, and outcome of 12 horses with clinically apparent West-Nile-Virus (WNV) infection are described. Methods: Case series RESULTS: The adult horses (age 6-18 years, 7 mares, 5 geldings) from Saxony and Saxony-Anhalt were presented with various clinical histories between September 2018 and September 2020. All horses were presented in August or September and no horse was vaccinated against WNV. Fever as the most common general clinical sign was present in 8/12 horses. The most common neurological signs were muscle fascicula...
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 (...
Wu J, Cui Y, Yu F, Muhatai G, Tao D, Zhao A, Ning C, Qi M.Piroplasmosis is a disease that negatively affects equine health worldwide. Hence, 324 blood samples were collected from grazing horses in ten sites in Xinjiang and testing them for the presence of Theileria equi and Babesia caballi by PCR of the EMA-1 gene and BC48 gene, respectively. Of the 324 blood samples, 161 (49.7%) were positive for equine piroplasms. The prevalence of T. equi was 38.9% (126/324), while that of B. caballi was 30.2% (98/324). The T. equi and B. caballi co-infection rate was 19.4% (63/324). From the 126 EMA-1 gene sequences and 98 BC48 gene sequences we obtained, 21 and ...
Marques C, da Silva B, Nogueira Y, Bezerra T, Tavares A, Borges-Silva W, Gondim L.The protozoan (syn. ) infects horses and has dogs as definitive hosts. Herein we aimed to detect in Brazilian horses destined for human consumption and to determine the frequency of infection in the examined animals. Muscle fragments from 51 horses were collected in a slaughterhouse in Bahia State during three different seasons of the year. Samples from six tissues from each animal were prepared for macroscopic and microscopic evaluation, using tissue grinding, squash and histology. sp. was observed in 100% of the examined horses. Selected samples were processed for transmission electron mi...
Ghafar A, Abbas G, Beasley A, Bauquier J, Wilkes EJA, Jacobson C, McConnell E, El-Hage C, Carrigan P, Cudmore L, Tennent-Brown B, Hurley J....This review is aimed to (i) appraise the literature on the use of molecular techniques for the detection, quantification and differentiation of gastrointestinal helminths (GIH) of equids, (ii) identify the knowledge gaps and, (iii) discuss diagnostic prospects in equine parasitology. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, we retrieved 54 studies (horses: 50/54; donkeys and zebras: 4/54) from four databases. Polymerase chain reaction (PCR) was employed in all of the studies whereas PCR amplicons were sequenced...
Hassanpour A, Moghaddam S.Early detection of Rhodococcus equi pneumonia in foals is essential for horse health and for veterinarians. Objective: This study aimed to demonstrate the usefulness of assessing the serum concentration of acute-phase proteins (APPs) in the early diagnosis of pneumonia. Methods: The study evaluated APPs in 19 Arabian foals with R. equi pneumonia and compared them with 18 normal Arabian foals in equestrian clubs in Tabriz, Iran. Affected foals were identified through history, clinical findings and bacterial culture of tracheal washing. Biochemical methods and polymerase chain reaction tests wer...
Schäfer I, Silaghi C, Fischer S, Marsboom C, Hendrickx G, Gehlen H, Müller E.Equine granulocytic anaplasmosis (EGA) is a tick-borne disease caused by Anaplasma (A.) phagocytophilum. In Germany, this pathogen is transmitted primarily by Ixodes ricinus. There is limited knowledge about its prevalence in horses in Germany. The aim of this retrospective study was to analyze the results of serological and molecular testing for A. phagocytophilum in horses which were done in a commercial laboratory in Germany over fourteen years. Additionally, risk factors were evaluated, and hematological abnormalities were addressed in horses with positive PCR results. Methods: This retros...
Finger MA, Biava JS, Dornbusch PT, Perotta JH, Ullmann LS, Serpa PBDS, Kmetiuk LB, Dos Santos AP, Biondo AW, Leutenegger C, Filho IRB.Molecular approaches to diagnose respiratory viruses have provided an opportunity for early and subclinical pathogen detection, particularly in samples from the upper respiratory tract. This study aimed to investigate the presence of herpesviruses, particularly equid herpesvirus (EHV)-2 and EHV-5, in samples from the lower respiratory tract of healthy racehorses from Southern Brazil. Unassigned: Samples from the lower respiratory tract (i.e., bronchoalveolar lavage fluid [BALF]) were assessed by video endoscopy, cytological evaluation of BALF, and tracheal aspirates (TA), along with quantitati...
Thirumalapura NR, Livengood J, Beeby J, Wang W, Goodrich EL, Goodman LB, Erol E, Tewari D.Neorickettsia risticii, an obligate intracellular bacterium, is the causative agent of Potomac horse fever (PHF). Diagnosis of PHF is based on demonstration of serum antibodies, isolation of N. risticii, and/or detection of nucleic acid by a PCR assay. An existing real-time PCR assay targeting the N. risticii 16S rRNA has been validated using blood samples from horses with colitis, and snails; to our knowledge, the performance of the assay for other sample types has not been reported. We describe here a modification of the 16S rRNA gene assay by the addition of a set of primers and probe targe...
Yoon J, Park T, Kim A, Park J, Park BJ, Ahn HS, Go HJ, Kim DH, Lee JB, Park SY, Song CS, Lee SW, Choi IS.Equine parvovirus-hepatitis (EqPV-H) is one of the etiological agents of Theiler's disease, causing fulminant hepatitis; however, its transmission route and pathogenesis remain unclear. In the present study, we aimed to determine EqPV-H shedding in oral/nasal/vaginal swabs or semen samples from horses living in Korea using nested polymerase chain reaction. We then used the data obtained to investigate various risk factors associated with EqPV-H including viral shedding, hepatopathological changes, and genetic diversity. Our data revealed occurrence of EqPV-H shedding in these animals (oral: 3/...
Nieri-Bastos FA, Lopes MG, Cançado PH, Rossa GA, Faccini JL, Gennari SM, Labruna MB.Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB ge...
Knight CG, Dunowska M, Munday JS, Peters-Kennedy J, Rosa BV.Equus caballus papillomavirus type 2 (EcPV-2) infection has been associated with equine genital squamous cell carcinomas (SCCs). However, quantitative PCR (qPCR) has not been performed to determine viral copy numbers within these lesions. Additionally, the frequency with which EcPV-2 can be detected in other common sites of equine SCC development remains uncertain. The aim of this study was to develop a qPCR assay to estimate the viral load in a variety of equine tissue samples. These included 40 SCC lesions, 19 penile non-SCC or precursor disease lesions, and 222 tissues without observable le...
Anastasi E, Giguère S, Berghaus LJ, Hondalus MK, Willingham-Lane JM, MacArthur I, Cohen ND, Roberts MC, Vazquez-Boland JA.The objective of this study was to identify the molecular mechanism of macrolide resistance in the actinomycete Rhodococcus equi, a major equine pathogen and zoonotic agent causing opportunistic infections in people. Methods: Macrolide-resistant (n = 62) and macrolide-susceptible (n = 62) clinical isolates of R. equi from foals in the USA were studied. WGS of 18 macrolide-resistant and 6 macrolide-susceptible R. equi was performed. Representative sequences of all known macrolide resistance genes identified to date were used to search the genome assemblies for putative homologues. PCR w...
Abutarbush SM, Alqawasmeh DM, Mukbel RM, Al-Majali AM.The purposes of this study were to estimate the seroprevalence and distribution of horse piroplasmosis, to evaluate risk factors associated with the occurrence of the disease and to compare the different diagnostic methods used for this disease. A total of 253 clinically normal horses were sampled, and a collection form was completed for each horse from five of six different climatic zones of Jordan. The sixth zone was not sampled because it did not include horse population. Competitive enzyme-linked immunosorbent assay (cELISA) revealed 37 horses (14.6%) positive for Theileria equi, and none ...
Salim BO, Hassan SM, Bakheit MA, Alhassan A, Igarashi I, Karanis P, Abdelrahman MB.The purpose of this study was to estimate the prevalence of equine piroplasmosis in Sudan. The presence of antibodies against Babesia caballi and Theileria equi was determined in serum samples obtained from 158 horses raised in different locations in Sudan by enzyme-linked immunosorbent assay (ELISA). The B. caballi 48-kDa and the T. equi EMA-2 purified recombinant proteins were used as antigens in the ELISA test. Results showed that seven (4.4%) were positive for B. caballi and 80 (63.5%) were positive for T. equi. Polymerase chain reaction (PCR) assays have been applied using primers targeti...
Mienaltowski MJ, Huang L, Frisbie DD, McIlwraith CW, Stromberg AJ, Bathke AC, Macleod JN.Full-thickness articular cartilage lesions that reach to the subchondral bone yet are restricted to the chondral compartment usually fill with a fibrocartilage-like repair tissue which is structurally and biomechanically compromised relative to normal articular cartilage. The objective of this study was to evaluate transcriptional differences between chondrocytes of normal articular cartilage and repair tissue cells four months post-microfracture. Methods: Bilateral one-cm2 full-thickness defects were made in the articular surface of both distal femurs of four adult horses followed by subchond...
Sant C, d'Abadie R, Pargass I, Basu AK, Asgarali Z, Charles RA, Georges KC.Equine piroplasmosis caused by Theileria equi and Babesia caballi is endemic in Trinidad and Tobago. Transmission occurs by ticks of the family Ixodidae. T. equi can also be transmitted transplacentally; however transplacental transmission of B. caballi is unknown. This study aims to investigate transplacental transmission of equine piroplasmosis from thoroughbred mares naturally infected via the tick vector. Whole blood and serum samples were collected from 117 mares in the fifth month of pregnancy. Blood samples were also collected from each of their foals (89 in total) within the first 36h ...
Li F, Su J, Chahan B, Guo Q, Wang T, Yu Z, Guo Y, Li N, Feng Y, Xiao L.Few studies have been conducted on the distribution of Cryptosporidium species and subtypes in equine animals. In this study, 878 stool specimens were collected during 2015-2019 from 551 donkeys and 327 horses in Shandong, Xinjiang, and Inner Mongolia, China and screened for Cryptosporidium spp. by PCR analysis of the small subunit rRNA gene. The Cryptosporidium species presented were identified by sequence analysis of the PCR products and subtyped by sequence analysis of the 60 kDa glycoprotein gene. The infection rates of Cryptosporidium spp. in horses and donkeys were 3.1% (10/327) and 14...
von Samson-Himmelstjerna G.Conventional and real time polymerase chain reaction-based tests have been developed for the diagnosis of anthelmintic resistance (AR) in populations of several small and large ruminant as well as horse gastro-intestinal nematode species. To date, molecular markers that correlate well with AR are available only for the detection of benzimidazole resistance. Recently, however, a single nucleotide polymorphism was found in vitro to be of functional relevance for reduced drug efficacy to macrocylic lactones. The focus of the present review, therefore, is the molecular mechanism of action of these...
Agüero M, Gómez-Tejedor C, Angeles Cubillo M, Rubio C, Romero E, Jiménez-Clavero A.African horse sickness is an arthropod-borne disease of the equine included in the World Organization for Animal Health (OIE) list with important economic consequences for horse trade. The disease is caused by African horse sickness virus (AHSV; family Reoviridae, genus Orbivirus), which is transmitted by Culicoides midges. It is endemic in sub-Saharan Africa, spreading occasionally outside this area where the occurrence of Culicoides vectors allows virus transmission. Currently, only conventional (gel-based) reverse transcription polymerase chain reaction (RT-PCR) protocols are available for ...
Franzén P, Aspan A, Egenvall A, Gunnarsson A, Aberg L, Pringle J.Six horses were experimentally infected by administration of horse blood containing a Swedish strain of Anaplasma phagocytophilum. The polymerase chain reaction (PCR) signal was consistently detected 2-3 days before appearance of clinical signs and persisted 4-9 days beyond abatement of clinical signs, whereas diagnostic inclusion bodies were 1st noted on average 2.6 +/- 1.5 (SD) days after onset of fever. Clinical signs and hematologic changes were largely indistinguishable from those previously reported for diseases caused by A phagocytophilum (formerly Ehrlichia equi--"Californian agent") a...
Hue ES, Fortier GD, Fortier CI, Leon AM, Richard EA, Legrand LJ, Pronost SL.Equid gammaherpesviruses-2 and -5 are involved in respiratory problems, with potential clinical manifestations such as nasal discharge, pharyngitis and swollen lymph nodes. These viruses are sometimes associated with a poor-performance syndrome, which may result in a significant and negative economic impact for the horse industry. The aim of the present study was to develop and validate quantitative PCR methods for the detection and quantitation of EHV-2 and EHV-5 in equine respiratory fluids. Two distinct tests were characterised: (a) for the qPCR alone and (b) for the whole method (extractio...
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...
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...
Lowe W, March JK, Bunnell AJ, O'Neill KL, Robison RA.Methods for the rapid detection and differentiation of the Burkholderia pseudomallei complex comprising B. pseudomallei, B. mallei, and B. thailandensis, have been the topic of recent research due to the high degree of phenotypic and genotypic similarities of these species. B. pseudomallei and B. mallei are recognized by the CDC as tier 1 select agents. The high mortality rates of glanders and melioidosis, their potential use as bioweapons, and their low infectious dose, necessitate the need for rapid and accurate detection methods. Although B. thailandensis is generally avirulent in mammals, ...
Vengust M, Jager MC, Zalig V, Cociancich V, Laverack M, Renshaw RW, Dubovi E, Tomlinson JE, Van de Walle GR, Divers TJ.Equine parvovirus-hepatitis (EqPV-H) has been proposed as the aetiological cause of Theiler's disease, also known as serum hepatitis. EqPV-H-associated Theiler's disease has not been previously reported in Europe. Objective: To determine whether EqPV-H infection was associated with a 2018-2019 outbreak of Theiler's disease in four horses on a studfarm. Methods: Descriptive case series. Methods: The medical records of four horses from the same farm diagnosed with fatal Theiler's disease were examined retrospectively. Information collected included a clinical history, physical examination findin...
Quinlivan M, Dempsey E, Ryan F, Arkins S, Cullinane A.Equine influenza is a cause of epizootic respiratory disease of the equine. The detection of equine influenza virus using real-time Light Cycler reverse transcription (RT)-PCR technology was evaluated over two influenza seasons with the analysis of 171 samples submitted for viral respiratory disease. Increased sensitivity was found in overall viral detection with this system compared to Directigen Flu A and virus isolation, which were 40% and 23%, respectively, that of the RT-PCR. The assay was also evaluated as a viable replacement for the more traditional methods of quantifying equine influe...
BMC research notesMarch 12, 2013
Volume 6 91 doi: 10.1186/1756-0500-6-91
Schoster A, Arroyo LG, Staempfli HR, Weese JS.The composition of the microbiota of the equine intestinal tract is complex. Determining whether the microbial composition of fecal samples is representative of proximal compartments of the digestive tract could greatly simplify future studies. The objectives of this study were to compare the microbial populations of the duodenum, ileum, cecum, colon and rectum (feces) within and between healthy horses, and to determine whether rectal (fecal) samples are representative of proximal segments of the gastrointestinal tract. Intestinal samples were collected from ten euthanized horses. 16S rRNA gen...
Kleiboeker SB, Schommer SK, Johnson PJ, Ehlers B, Turnquist SE, Boucher M, Kreeger JM.Over a period of 6 years, antemortem and postmortem examinations were performed on a number of donkeys suffering from respiratory disease. For many cases, initial diagnostic efforts failed to identify an etiology consistent with the pathologic findings. However, retrospective examination of these cases using consensus primer polymerase chain reaction, designed to recognize herpesviruses from all 3 subfamilies of the Herpesviridae, amplified a fragment of the highly conserved herpesvirus DNA polymerase gene from a number of these animals. Two novel herpesviruses, herein designated asinine herpe...
Laus F, Preziuso S, Spaterna A, Beribè F, Tesei B, Cuteri V.An outbreak of strangle-like disease involving 26 horses farmed in central Italy was investigated by clinic examination, endoscopy, cytology, bacteriology and polymerase chain reaction (PCR). At weekly interval, a total of three nasal swabs and one guttural pouches lavage fluid (GPLF) were collected, and no Streptococcus equi subsp. equi carrier was found. Some horses showed upper airways disease and endoscopic signs of pharyngeal lymphoid hyperplasia of different grade and/or abnormal endoscopic appearance of guttural pouches. Streptococcus dysgalactiae subsp. equisimilis was isolated from 14...
Lu G, Sun L, Xu T, He D, Wang Z, Ou S, Jia K, Yuan L, Li S.Since 2012, three viruses, known as equine hepacivirus (EqHV), equine pegivirus (EPgV) and Theiler's disease-associated virus (TDAV), have been discovered in equines. Given that these viruses are the newest members of the Flaviviridae family, genomic information concerning circulating EqHV, EPgV and TDAV strains around the world is limited. To date, no genetic surveillance studies have been performed on these three viruses in the equine population of China. Here, a total of 177 serum samples were collected from equines across China between 2014 and 2015. Using PCR, we detected viral RNA in the...
Theegarten D, Sachse K, Mentrup B, Fey K, Hotzel H, Anhenn O.Recurrent airway obstruction (RAO) in horses is a naturally occurring dust-induced disease mainly characterized by bronchiolitis which shows histological and pathophysiological similarities to human chronic obstructive pulmonary disease (COPD). In human COPD previous investigations indicated an association with Chlamydophila psittaci infection. The present study was designed (1) to clarify a possible role of this infectious agent in RAO and (2) to investigate the suitability of this equine disorder as a model for human COPD. Methods: Clinico-pathological parameters of a total of 45 horses (25 ...
Knight CG, Munday JS, Peters J, Dunowska M.Forty cases of equine penile disease were screened with polymerase chain reaction for the presence of papillomaviral DNA. Cases consisted of 20 squamous cell carcinomas (average age of horse, 23.9 years) and 20 non-squamous cell carcinoma diseases (average age of horse, 13.3 years). All horses but one originated from the Northeastern United States. Breeds were not recorded. As based on MY09/MY11 consensus primers, DNA sequences from equine papillomavirus type 2 were amplified from 9 of 20 horses (45%) with penile squamous cell carcinoma and only 1 of 20 horses (5%) with non-squamous cell carci...
Johnson DJ, Ostlund EN, Pedersen DD, Schmitt BJ.A traditional single-stage reverse transcription-polymerase chain reaction (RT-PCR) procedure is effective in determining West Nile (WN) virus in avian tissue and infected cell cultures. However, the procedure lacks the sensitivity to detect WN virus in equine tissue. We describe an RT-nested PCR (RT-nPCR) procedure that identifies the North American strain of WN virus directly in equine and avian tissues.
Elfving K, Malmsten J, Dalin AM, Nilsson K.Both Rickettsia helvetica and Anaplasma phagocytophilum are common in Ixodes ricinus ticks in Sweden. Knowledge is limited regarding different animal species' competence to act as reservoirs for these organism. For this reason, blood samples were collected from wild cervids (roe deer, moose) and domestic mammals (horse, cat, dog) in central Sweden, and sera were tested using immunofluorescence assay to detect antibodies against spotted fever rickettsiae using Rickettsia helvetica as antigen. Sera with a titer ≥1:64 were considered as positive, and 23.1% (104/450) of the animals scored positi...
Nakamura Y, Kishi M, Nakaya T, Asahi S, Tanaka H, Sentsui H, Ikeda K, Ikuta K.Borna disease (BD) is a progressive poliomeningoencephalomyelitis which occurs naturally in horses and sheep. Here, peripheral blood mononuclear cells (PBMC) derived from 57 healthy horses in Japan were examined by a nested reverse transcription-polymerase chain reaction to determine the prevalence of BD virus (BDV) infection. Seventeen (29.8%) of the samples were positive by this examination and the specificity of the amplified product was confirmed by hybridization with authentic oligomer probes. About 60% of the BDV RNA-positive individuals also showed seropositivity by Western blotting. Th...
St-Laurent G, Morin G, Archambault D.A reverse transcription (RT)-PCR assay was developed for the detection of equine arteritis virus (EAV) in cell culture supernatant and in horse semen. Four different sets of oligonucleotide primers complementary to sequences located in the 3' end of the polymerase gene (open reading frame [ORF] 1b) and to sequences representing the entire ORFs 3, 4, and 7, which encode for nonstructural (ORFs 3 and 4) or viral nucleocapsid (ORF 7) proteins, were compared for their abilities to amplify the targeted EAV sequences by the RT-PCR procedure. The sensitivities of the RT-PCR for amplification of EAV s...
Szeredi L, Hotzel H, Sachse K.Seventy-seven cases of equine abortion from 49 Hungarian farms that occurred between 1998 and 2000 were investigated for the presence of chlamydiae by immunohistochemistry, PCR and/or MZN staining. Evidence of the presence of these bacteria was obtained in 64 cases (83.1%) from 41 (83.7%) different farms. Partial ompA gene sequencing of PCR products revealed that the agent was Chlamydophila psittaci. Based on the findings of microbial diagnosis, pathology and case history, chlamydial infection was considered to be the most likely cause of abortion in at least 11 (14.3%) cases. In the remaining...
Jaffer O, Abdishakur F, Hakimuddin F, Riya A, Wernery U, Schuster RK.A total of 105 serum samples from endurance horses from different stables in Dubai were examined for the presence of antibodies against Theileria equi and Babesia caballi using immunofluorescence antibody test (IFAT) and competitive enzyme-linked immunosorbent assay (cELISA). A TaqMan real-time polymerase chain reaction (PCR) was used to detect DNA of piroplasms in specimens of clotted blood or EDTA blood samples of the same animals. Out of the 105 serum samples, the IFAT detected antibodies against T. equi in 35 (33.3%) cases while the cELISA gave 34 (32.4%) positive results. Eleven (10.5%) o...
Wen B, Rikihisa Y, Fuerst PA, Chaichanasiriwithaya W.Ehrlichia risticii is the causative agent of Potomac horse fever. Variations among the major antigens of different local E. risticii strains have been detected previously. To further assess genetic variability in this species or species complex, the sequences of the 16S rRNA genes of several isolates obtained from sick horses diagnosed as having Potomac horse fever were determined. The sequences of six isolates obtained from Ohio and three isolates obtained from Kentucky were amplified by PCR. Three groups of sequences were identified. The sequences of five of the Ohio isolates were identical ...
