Pathogens are microorganisms, such as bacteria, viruses, fungi, and parasites, that can cause disease in horses. These microorganisms interact with the equine immune system, often leading to a range of health issues that can affect individual horses or entire populations. Pathogens can be transmitted through various routes, including direct contact, vectors, or environmental exposure. Common equine pathogens include Streptococcus equi, Equine Herpesvirus, and Strongylus vulgaris. Understanding the interactions between equine hosts and pathogens is essential for disease prevention, management, and treatment. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, transmission, and impact of pathogens on equine health.
Padilla SL, Prieto K, Dohm DJ, Turell MJ, Klein TA, Fernández R, Watts DM, Lowen RG, Palacios GF, Pitt ML, Wiley MR, Nasar F.Venezuelan equine encephalitis virus (VEEV) is an important pathogen of medical and veterinary importance in the Americas. In this report, we present the complete genome sequences of five VEEV isolates obtained from pools of Culex (Melanoconion) gnomatos (4) or Culex (Melanoconion) pedroi (1) from Iquitos, Peru. Genetic and phylogenetic analyses showed that all five isolates grouped within the VEEV complex sister to VEEV IIIC and are members of subtype IIID. This is the first report of full-length genomic sequences of VEEV IIID.
Tamura N, Okano A, Kuroda T, Niwa H, Kusano K, Matsuda Y, Fukuda K, Mita H, Nagata S.To clarify the detailed pharmacokinetics (PK) of orally administered voriconazole in tear fluid (TF) of horses for evaluating the efficacy of voriconazole secreted into TF against equine keratomycosis. Methods: Five healthy Thoroughbred horses. Methods: Voriconazole was administrated through a nasogastric tube to each horse at a single dose of 4.0 mg/kg. TF and blood samples were collected before and periodically throughout the 24 hours after administration. Voriconazole concentrations in plasma and TF samples were analyzed using liquid chromatography-electrospray tandem-mass spectrometry. T...
Kalinowski M, Jarosz Ł, Grądzki Z.Rhodococcus equi is an opportunistic, intracellular saprophyte that causes severe pyogranulomatous pneumonia in foals. The bacterium displays in vitro susceptibility to many antibiotics. The highest efficacy against R. equi in vitro and in vivo is achieved by using a combination of rifampicin and macrolide antibiotics. Recent years have seen an upward trend in the minimum inhibitory concentration (MIC) of rifampicin and erythromycin, suggesting increasing resistance of R. equi to these antibiotics. The aim of the study was to determine the antimicrobial activity of 24 selected antibiotics...
Léon A, Castagnet S, Maillard K, Paillot R, Giard JC.The present study described the evolution of antimicrobial resistance in equine pathogens isolated from 2016 to 2019. A collection of 7806 bacterial isolates were analysed for their in vitro antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.0%), Escherichia coli (18.0%), Staphylococcus aureus (6.2%), Pseudomonas aeruginosa (3.4%), Klebsiella pneumoniae (2.3%) and Enterobacter spp. (2.1%). The majority of these pathogens were isolated from the genital tract (45.1%, n = 3522). With the implementation of two French n...
Mullen KR, Rivera BN, Tidwell LG, Ivanek R, Anderson KA, Ainsworth DM.Studies of neonatal health risks of unconventional natural gas development (UNGD) have not included comprehensive assessments of environmental chemical exposures. We investigated a clustering of dysphagic cases in neonatal foals born between 2014 and 2016 in an area of active UNGD in Pennsylvania (PA),USA. We evaluated equine biological data and environmental exposures on the affected PA farm and an unaffected New York (NY) farm owned by the same proprietor. Dams either spent their entire gestation on one farm or moved to the other farm in late gestation. Over the 21-month study period, physic...
Song R, Ma Y, Hu Z, Li Y, Li M, Wu L, Li C, Dao E, Fan X, Hao Y, Bayin C.Dermacentor marginatus Sulkzer is a common tick species found in the Xinjiang Uygur Autonomous Region (XUAR) of China, and is a vector for a variety of pathogens. To determine the potential distribution of this tick species in Xinjiang, a metadata containing 84 D. marginatus presence records combined with four localities from field collection were used for MaxEnt modeling to predict potential distribution of this tick species. Identification of tick samples showed 756 of 988 (76%) were D. marginatus. MaxEnt modeling results indicated that the potential distribution of this tick species was mai...
Seo MG, Kwon OD, Kwak D.Lyme borreliosis is one of the most prevalent tick-borne infectious zoonotic diseases caused by spirochetes of the sensu lato group. The present study assessed the risk factors and prevalence of Lyme borreliosis in ticks parasitizing domestic and wild animals. A total of 589 ticks (329 tick pools) collected from animals were identified as , (85.7%), (10.0%), and (4.3%) using morphological and molecular methods in South Korea. In this study, the 5S-23S gene sequences of (6/329, 1.8%) were detected in ticks taken from mammals, including ticks from horses (2/147 pools, 1.4%), wild boar (1/19 ...
Kampen H, Holicki CM, Ziegler U, Groschup MH, Tews BA, Werner D.In 2018, West Nile virus (WNV) broke out for the first time in Germany, with continuation of the epidemic in 2019, involving birds, horses and humans. To identify vectors and characterize the virus, mosquitoes were collected in both years in zoological gardens and on a horse meadow immediately following the diagnosis of disease cases in birds and horses. Mosquitoes were identified and screened for WNV by qRT-PCR, with virus-positive samples being sequenced for the viral envelope protein gene. While no positive mosquitoes were found in 2018, seven mosquito pools tested positive for WNV in 2019 ...
Lab on a chipApril 26, 2020
Volume 20, Issue 9 1621-1627 doi: 10.1039/d0lc00304b
Sun F, Ganguli A, Nguyen J, Brisbin R, Shanmugam K, Hirschberg DL, Wheeler MB, Bashir R, Nash DM, Cunningham BT.Rapid, sensitive and specific detection and reporting of infectious pathogens is important for patient management and epidemic surveillance. We demonstrated a point-of-care system integrated with a smartphone for detecting live virus from nasal swab media, using a panel of equine respiratory infectious diseases as a model system for corresponding human diseases such as COVID-19. Specific nucleic acid sequences of five pathogens were amplified by loop-mediated isothermal amplification on a microfluidic chip and detected at the end of reactions by the smartphone. Pathogen-spiked horse nasal swab...
Álvarez-Narváez S, Giguère S, Berghaus LJ, Dailey C, Vázquez-Boland JA.Conjugation is one of the main mechanisms involved in the spread and maintenance of antibiotic resistance in bacterial populations. We recently showed that the emerging macrolide resistance in the soilborne equine and zoonotic pathogen is conferred by the (46) gene carried on the 87-kb conjugative plasmid pRErm46. Here, we investigated the conjugal transferability of pRErm46 to 14 representative bacteria likely encountered by in the environmental habitat. mating experiments demonstrated conjugation to different members of the genus as well as to and spp. at frequencies ranging from ∼10...
Van Cleemput J, Poelaert KCK, Laval K, Vanderheijden N, Dhaenens M, Daled S, Boyen F, Pasmans F, Nauwynck HJ.β-Defensins protect the respiratory tract against the myriad of microbial pathogens entering the airways with each breath. However, this potentially hostile environment is known to serve as a portal of entry for herpesviruses. The lack of suitable respiratory model systems has precluded understanding of how herpesvirus virions overcome the abundant mucosal β-defensins during host invasion. We demonstrate how a central alphaherpesvirus, equine herpesvirus type 1 (EHV1), actually exploits β-defensins to invade its host and initiate viral spread. The equine β-defensins (eBDs) eBD1, -2, and -3...
Marx C, Gardner S, Harman RM, Van de Walle GR.Mesenchymal stromal cells (MSCs) from various species, such as humans, mice, and horses, were recently found to effectively inhibit the growth of various bacteria associated with chronic infections, such as nonhealing cutaneous wounds, via secretion of antimicrobial peptides. These MSC antimicrobial properties have primarily been studied in the context of the planktonic phenotype, and thus, information on the effects on bacteria in biofilms is largely lacking. The objectives of this study were to evaluate the in vitro efficacy of the MSC secretome against various biofilm-forming wound pathogen...
Sciorsci RL, Lillo E, Occhiogrosso L, Rizzo A.Ozone (O) is a triatomic form of oxygen. As O rapidly dissociates into water and releases a reactive form of oxygen that may oxidize cells, the gas mixture of O/O is used in medicine. ATP is widely available for cellular activity. O can be administered via the systemic and local routes. Although O is known as one of the most powerful oxidants, it also promotes antioxidant enzymes. Additionally, it stimulates some of the cells of the immune system and inactivates pathogens, including bacteria, fungi, yeasts, protozoa, and viruses. Owing to these activities, O is used to improve several diseases...
de Lagarde M, Fairbrother JM, Arsenault J.Although antimicrobial resistance is an increasing threat in equine medicine, molecular and epidemiological data remain limited in North America. We assessed the prevalence of, and risk factors for, shedding multidrug-resistant (MDR) and extended-spectrum β-lactamase (ESBL) and/or AmpC β-lactamase-producing in healthy horses in Quebec, Canada. We collected fecal samples in 225 healthy adult horses from 32 premises. A questionnaire on facility management and horse medical history was completed for each horse. Indicator (without enrichment) and specific (following enrichment with ceftriaxone)...
Santos RG, Hurtado R, Gomes LGR, Profeta R, Rifici C, Attili AR, Spier SJ, Mazzullo G, Morais-Rodrigues F, Gomide ACP, Brenig B, Gala-García A....Bacteria of the genusGlutamicibacterare considered ubiquitous because they can be found in soil, water and air. They have already been isolated from different habitats, including different types of soil, clinical samples, cheese and plants. Glutamicibacter creatinolyticus is a Gram-positive bacterium important to various biotechnological processes, however, as a pathogen it is associated to urinary tract infections and bacteremia. Recently,Glutamicibacter creatinolyticusLGCM 259 was isolated from a mare, which displayed several diffuse subcutaneous nodules with heavy vascularization. In this s...
Chambers TM.Equine influenza virus (EIV) is a common respiratory pathogen of horses and other equids in most parts of the world. EIV are Type A influenza viruses and two subtypes are known: H3N8 and H7N7. Both are believed to have evolved from avian influenza virus ancestors. The H3N8 subtype circulates widely, but the H7N7 subtype is thought to be extinct. The clinical disease in horses, caused by either subtype, is an upper respiratory infection of varying severity depending upon the immune status of the individual animal. It is not normally life-threatening in itself except in very young foals; however...
Noll LW, Stoy CPA, Wang Y, Porter EG, Lu N, Liu X, Burklund A, Peddireddi L, Hanzlicek G, Henningson J, Chengappa MM, Bai J.Streptococcus equi subsp. equi is a Gram positive bacterial pathogen commonly associated with strangles in horses, a respiratory disease characterized by abscessation of submandibular and retropharyngeal lymph nodes which can lead to obstruction of the airway. Several real-time PCR (qPCR) assays have been developed for detection of S. equi from horses with many targeting conserved regions of the S. equi cell wall-associated M-protein (SeM), a major virulence factor and immunogen of S. equi. Our objective was to develop a nested PCR (nPCR) targeting SeM and an 18S rRNA internal control gene for...
de Lagarde M, Larrieu C, Praud K, Lallier N, Trotereau A, Sallé G, Fairbrother JM, Schouler C, Doublet B.The objective of the study was to identify the genetic determinants and characteristics of expanded-spectrum cephalosporin (ESC) resistance in commensal Escherichia coli from healthy horses in France in 2015. Faecal samples from 744 adult horses were screened for ESC-resistant E. coli isolates. The extended-spectrum beta-lactamase (ESBL)/AmpC resistance genes were identified using polymerase chain reaction (PCR) and sequencing. ESC phenotypes were horizontally transferred by conjugation or transformation. Plasmids carrying ESBL/AmpC genes were typed by PCR-based replicon typing, restriction fr...
Kinoshita Y, Niwa H, Uchida-Fujii E, Nukada T.Mycoplasma felis causes conjunctivitis in cats and respiratory diseases in horses. We report here the complete genome assembly of equine Mycoplasma felis strain Myco-2, which was isolated from an ill horse in Japan.
Tirosh-Levy S, Steinman A, Einhorn A, Apanaskevich DA, Mumcuoglu KY, Gottlieb Y.Theileria equi Mehlhorn and Schein, 1998 (Piroplasmida: Babesiidae) is an important tick-borne pathogen of horses that is highly endemic in many parts of the world, including Israel. The present study evaluated the potential roles of five hard tick species [Hyalomma excavatum Koch, 1844; Hyalomma marginatum Koch, 1844; Rhipicephalus turanicus Pomerantsev 1936; Rhipicephalus annulatus Say, 1821; Haemaphysalis parva (Neumann, 1897) (all: Ixodida: Ixodidae)], previously found to infest horses in Israel, in acting as vectors for piroplasmosis. For this, DNA was extracted from whole ticks and, when...
Canever MF, Miletti LC.The development of new drugs targeting neglected animal diseases is imperative. In Asia and South America, Trypanosoma evansi is a pathogen that affects horses and other species, causing economic losses associated with reduced animal productivity and death. In order to accelerate the identification of drugs with activity against neglected diseases, Medicines for Malaria Venture has developed Pathogen Box®, a library of 400 different molecules. The present work aimed to identify compounds present in the Pathogen Box® library, measuring in vitro activity against T. evansi. Among the 400 compou...
Estell KE, Knych HK, Patel T, Edman JM, Magdesian KG.To the authors' knowledge, there have been no studies evaluating the pharmacokinetics of chloramphenicol administered orally to horses at the currently recommended dose of 50 mg/kg PO q6 h for multiple days. The published antimicrobial susceptibility breakpoint is 8.0 ug/mL; it is unknown if this concentration is achievable at the recommended dose rate in horses. The aim of this prospective multi-dose pharmacokinetic study was to perform pharmacokinetic analysis of chloramphenicol after multiple doses. The authors hypothesize that the antimicrobial susceptibility breakpoint will not be reached...
Sack A, Oladunni FS, Gonchigoo B, Chambers TM, Gray GC. Worldwide, horses play critical roles in recreation, food production, transportation, and as working animals. Horses' roles differ by geographical region and the socioeconomic status of the people, but despite modern advances in transportation, which have in some ways altered humans contact with horses, potential risks for equine zoonotic pathogen transmission to humans occur globally. While previous reports have focused upon individual or groups of equine pathogens, to our knowledge, a systematic review of equine zoonoses has never been performed. Using PRISMA's systematic review guidelines...
Popoff MR.Tetanus is a neurologic disease of humans and animals characterized by spastic paralysis. Tetanus is caused by tetanus toxin (TeNT) produced by Clostridium tetani, an environmental soilborne, gram-positive, sporulating bacterium. The disease most often results from wound contamination by soil containing C. tetani spores. Horses, sheep, and humans are highly sensitive to TeNT, whereas cattle, dogs, and cats are more resistant. The diagnosis of tetanus is mainly based on the characteristic clinical signs. Identification of C. tetani at the wound site is often difficult.
El-Sheikh Ali H, Boakari YL, Loux SC, Dini P, Scoggin KE, Esteller-Vico A, Kalbfleisch T, Ball BA.The key event in placentitis-induced preterm labor is myometrial activation with the subsequent initiation of labor. However, the molecular mechanisms underlying myometrial activation are not fully understood in the mares. Therefore, the equine myometrial transcriptome was characterized during placentitis (290.0 ± 1.52 days of GA, n = 5) and the prepartum period (330 days of GA, n = 3) in comparison to normal pregnant mares (289.8 ± 2.18 days of GA, n = 4). Transcriptome analysis identified 596 and 290 DEGs in the myometrium during placentitis and the prepartum period, respectively...
Wilson ME, McCandless EE, Olszewski MA, Robinson NE.Because the alveolar macrophage (AM) phenotype of horses with severe equine asthma (SEA) is unknown, the cytokines expressed by M1- and M2-polarized AM were determined and the hypothesis that natural hay/straw challenge (NC) induces divergent AM phenotypes in control horses and horses with SEA was tested. Macrophages from control horses were activated either with eIFNγ + lipolysaccharide (LPS) or eIL-4 to characterize M1- or M2-polarized AM gene expression, respectively and determine the response of polarized cells to pathogen-associated molecular patterns (PAMPS): LPS, zymosan, peptidoglycan...
Theelen MJP, Wilson WD, Byrne BA, Edman JM, Kass PH, Mughini-Gras L, Magdesian KG.Antimicrobial treatment protocols for foals with sepsis that do not improve clinically often are adjusted based on bacteriological and antimicrobial susceptibility testing results from samples collected at hospital admission. Objective: To evaluate whether hospitalization for ≥48 hours affects bacteriological and antimicrobial susceptibility testing results. Methods: Two-hundred sixty-seven foals <30 days of age admitted to a neonatal intensive care unit and diagnosed with sepsis. Methods: Medical records were reviewed retrospectively to identify foals with sepsis and positive bacteri...
Li F, Wang R, Guo Y, Li N, Feng Y, Xiao L.Limited data are available on infection rates and genetic identity of Enterocytozoon bieneusi and Giardia duodenalis in horses and donkeys. In this study, 865 fecal specimens were collected from donkeys (n = 540) and horses (n = 325) in three provinces and autonomous regions in northern China during 2015-2019. Enterocytozoon bieneusi was detected and genotyped by PCR and sequence analyses of the ribosomal internal transcribed spacer (ITS) and G. duodenalis was detected and genotyped by PCR and sequence analyses of the β-giardin, glutamate dehydrogenase, and triosephosphate isomerase g...
Veado HC, Conceição RS, Nogueira K, Fino TCM, Silva AS, Castro MB, Soto-Blanco B, Câmara ACL.The findings of massive Africanized honeybee stings in two hair sheep and a mare are reported. One sheep died 15 h after attack, and the survivors developed skin necrosis on the sting sites. Pathological evaluation revealed necrosis in the dermis, degeneration of the tubular epithelial cells, and multifocal hemorrhages in heart and spleen. The massive attack by Africanized honeybees induced lesions in the skin, heart, muscles, kidneys, and lungs.
Manguin E, Pépin E, Boivin R, Leclere M.There are limited data on potential dysbiosis of the airway microbiota in horses with asthma. Objective: We hypothesized that the respiratory microbiota of horses with moderate asthma is altered. Our objectives were (a) to quantify tracheal bacterial populations using culture and qPCR, (2) to compare aerobic culture and qPCR, and (c) to correlate bacterial populations with bronchoalveolar lavage fluid (BALF) cytology. Methods: Eighteen horses with moderate asthma from a hospital population and 10 controls. Methods: Prospective case-control study. Aerobic culture was performed on tracheal aspir...
Braga FR, Araújo JV, Silva AR, Carvalho RO, Araujo JM, Ferreira SR, Carvalho GR.The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) embedded in sodium alginate pellets after passage through the gastrointestinal tract of horses was assessed in vitro against Oxyuris equi eggs. Twelve previously dewormed crossbred mares, average weight of 362.5kg (+/-21) were used in the experiment. Each animal of the treated group received an oral dose (100g) of sodium alginate pellets containing P. chlamydosporia mycelial mass. The control group received pellets without fungus. Faecal samples from fungus-treated and control groups were collected at inte...
Giguère S, Polkes AC.Foals live in an environment heavily populated by bacteria, many of which are capable of causing disease. Development of infection,however, is the exception rather than the rule. The ability of the foal to prevent infection by most pathogens is the result of a sophisticated set of defense mechanisms. These defense mechanisms can be divided into adaptive and innate immunity. Innate immunity encompasses defense mechanisms that pre-exist or are rapidly induced within hours of exposure to a pathogen. Conversely, adaptive or acquired immunity represents host defenses mediated by T and B lymphocytes...
Peters SE, Wakefield AE, Whitwell KE, Hopkin JM.Genetically distinct forms of Pneumocystis carinii infect several mammalian hosts. We report the amplification of P. carinii DNA from samples of two infected thoroughbred foal lungs by using primers designed from the sequence of a P. carinii mitochondrial rRNA gene; these primers also prime the amplification of P. carinii DNA from other hosts. The nucleotide sequence of part of the mitochondrial rRNA gene amplified from P. carinii infecting one of the foals was determined and found to be distinct from that of published rat-, rabbit-, ferret-, and human-derived P. carinii sequences.
Ellis WA, Bryson DG, O'Brien JJ, Neill SD.During an investigation of equine abortion, leptospiral infection was demonstrated in nine out of 22 foetuses examined by immunofluorescence and culture. Strains belonging to four serogroups (Australis, Pomona, Hebdomadis and Icterohaemorrhagiae) were isolated. The age of leptospira infected foetuses ranged from six months to term.
Martens RJ, Takai S, Cohen ND, Chaffin MK, Liu H, Sakurai K, Sugimoto H, Lingsweiler SW.To determine whether isolation and virulence of Rhodococcus equi from soil and infected foals are associated with clinical disease. Methods: Cross-sectional and case-control study. Methods: R equi isolates from 50 foals with pneumonia and soil samples from 33 farms with and 33 farms without a history of R equi infection (affected and control, respectively). Methods: R equi was selectively isolated from soil samples. Soil and clinical isolates were evaluated for virulence-associated protein antigen plasmids (VapA-P) and resistance to the beta-lactam antibiotics penicillin G and cephalothin. Mic...
Karabatsos N, Lewis AL, Calisher CH, Hunt AR, Roehrig JT.A virus, strain 64A-1519, isolated from the brain of a horse dying of encephalitis in Florida in 1964, was identified as western equine encephalomyelitis (WEE) virus. Recently, we used polyclonal and monoclonal immune reagents to identify this isolate by comparing it to 2 strains of WEE virus and to Highlands J (HJ) virus in hemagglutination-inhibition, immunofluorescent antibody, and plaque-reduction neutralization tests. These tests demonstrate that strain 64A-1519 is a strain of HJ virus distinct from WEE virus.
Barlough JE, Rikihisa Y, Madigan JE.A nested polymerase chain reaction was developed for amplifying a 529-bp segment of the 16S ribosomal RNA gene of Ehrlichia risticii from equine buffy coat cells. Confirmation of identity of the amplified bands was accomplished by Southern hybridization and DNA sequencing. The study indicated a detection limit of > 10 copies of the target gene, and specificity for E. risticii as based on a panel of test rickettsiae. Ticks (Ixodes pacificus) collected in an area of northern California enzootic for equine monocytic ehrlichiosis were found to be negative for E. risticii DNA.
Pusterla N, Leutenegger CM, Sigrist B, Chae JS, Lutz H, Madigan JE.A real-time quantitative PCR using the TaqMan fluorogenic detection system (TaqMan PCR) was established for identification of Ehrlichia risticii, the agent of Potomac horse fever (PHF). The TaqMan PCR identified an 85 base pair section of the 16S rRNA gene by use of a specific fluorogenic probe and two primers. This technique was specific for eight tested E. risticii strains. The TaqMan system identified 10 copies of a cloned section of the 16S rRNA gene of E. risticii. The sensitivity and specificity of the TaqMan PCR were similar to those of conventional nested PCR. The TaqMan PCR was evalua...
Sweeney CR, Divers TJ, Benson CE.Anaerobic bacteria are important and overlooked bacterial pathogens of the lower respiratory tract in horses. Twenty-one of 46 horses with pleuropneumonia had anaerobic bacteria isolated from pleural fluid or from tracheobronchial aspirate. Bacteroides oralis and B melaninogenicus were the anaerobes most frequently isolated. Survival was significantly less for horses from which anaerobes were isolated than for horses from which anaerobes were not isolated. Putrid odor was associated with the pleural fluid and/or breath in 62% of the horses from which anaerobes were isolated. In these horses, t...
Chanter N, Talbot NC, Newton JR, Hewson D, Verheyen K.The M-protein genes of Streptococcus equi isolated from 17 outwardly healthy horses after 4 strangles outbreaks had ended, including a quarantined animal, were compared with those of S. equi isolates from 167 active cases of strangles across 4 countries. The healthy horses included 16 persistent S. equi carriers, at least one from each of the four outbreaks. These carriers, despite being outwardly healthy, had empyema of the guttural pouch(es), an enlargement of the equine Eustachian tube. A persistent carrier from two of these outbreaks, the quarantined animal and a healthy animal with normal...
Coultous RM, McDonald M, Raftery AG, Shiels BR, Sutton DGM, Weir W.Theileria equi, one of the primary pathogens causing equine piroplasmosis, has previously been sub-classified into a number of clades on the basis of 18S SSU rRNA gene sequence diversity. This partitioning of the parasite population has potential implications for host immunity, treatment and vaccine development. To detect and identify different clade genotypes among and within individual equine blood samples, a novel PCR-based technique was designed and optimized. Theileria equi has only recently been described in The Gambia, and the developed genotyping technique was used to analyse blood sam...
Donahue JM, Smith BJ, Poonacha KB, Donahoe JK, Rigsby CL.In this study, the prevalence of leptospira-induced abortions/stillbirths for the past 3 foaling seasons (1991-1993) was determined, and fetal tissues and/or the mare's urine from positive cases were cultured in an attempt to isolate and identify the leptospira serovars responsible for the abortions. The sensitivity and specificity of the primary diagnostic tests, the fluorescent antibody test (FAT) and the microscopic agglutination test (MAT), used for the diagnosis of leptospirosis were also determined. For the 3 years, 74 (3.3%) of 2,264 abortion/stillborn submissions were diagnosed as lept...
Galuppo LD, Pascoe JR, Jang SS, Willits NH, Greenman SL.To document natural bacterial flora on the ventral aspect of the equine abdomen, to compare 2 preparation techniques, and to identify potential risk factors that may contribute to incisional drainage. Methods: Prospective study. Methods: 53 horses undergoing exploratory celiotomy. Methods: Group-1 horses (n = 26) were prepared with povidone-iodine and alcohol. Group-2 horses (27) were prepared with a film-forming iodophor complex. Numbers of bacterial colony-forming units (CFU) were measured before and after surgical scrub, following skin closure, and after recovery from general anesthesia. Sw...
Akter R, El-Hage CM, Sansom FM, Carrick J, Devlin JM, Legione AR.Abortion in horses leads to economic and welfare losses to the equine industry. Most cases of equine abortions are sporadic, and the cause is often unknown. This study aimed to detect potential abortigenic pathogens in equine abortion cases in Australia using metagenomic deep sequencing methods. Results: After sequencing and analysis, a total of 68 and 86 phyla were detected in the material originating from 49 equine abortion samples and 8 samples from normal deliveries, respectively. Most phyla were present in both groups, with the exception of Chlamydiae that were only present in abortion sa...
Costa-Farré C, Prades M, Ribera T, Valero O, Taurà P.Decreased tissue oxygenation is a critical factor in the development of wound infection as neutrophil mediated oxidative killing is an essential mechanism against surgical pathogens. The objective of this prospective case series was to assess the impact of intraoperative arterial partial pressure of oxygen (PaO2) on surgical site infection (SSI) in horses undergoing emergency exploratory laparotomy for acute gastrointestinal disease. The anaesthetic and antibiotic protocol was standardised. Demographic data, surgical potential risk factors and PaO2, obtained 1h after induction of anaesthesia w...
Yamanaka T, Nemoto M, Bannai H, Tsujimura K, Kondo T, Matsumura T, Muranaka M, Ueno T, Kinoshita Y, Niwa H, Hidari KI, Suzuki T.Since equine influenza A virus (H3N8) was transmitted to dogs in the United States in 2004, the causative virus, which is called canine influenza A virus (CIV), has become widespread in dogs. To date, it has remained unclear whether or not CIV-infected dogs could transmit CIV to horses. To address this, we tested whether or not close contact between horses and dogs experimentally infected with CIV would result in its interspecies transmission. Methods: Three pairs of animals consisting of a dog inoculated with CIV (10(8.3) egg infectious dose 50/dog) and a healthy horse were kept together in i...
McCollum WH.Nineteen horses with no prior experience with equine arteritis virus (EAV) were inoculated IM with an avirulent live-virus vaccine against equine viral arteritis; the vaccinal virus had been passaged serially 131 times in primary cell cultures of equine kidney, 111 times in primary cell cultures of rabbit kidney, and 16 times in an equine dermis cell line (EAV HK-131/RK-111/ED-16). Three or 4 of the vaccinated horses each, along with appropriate nonvaccinated controls, were inoculated nasally with virulent EAV at each of months 3, 6, 9, 12, 18, and 24 after they were vaccinated. The following ...
Christoffersen M, Söderlind M, Rí»ºlk SR, Pedersen HG, Allen J, Krekeler N.Infectious endometritis is a major cause of infertility in the mare and inflicts major losses on the equine breeding industry. The ability of the mare to eliminate uterine infections has been studied intensively for decades; however, despite identification of several factors contributing to the multifactorial pathogenesis and improved treatment, infectious endometritis remains a significant problem in a subpopulation of broodmares. Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is one of the most commonly isolated pathogens from the uterus of mares, suffering from infectious endom...
Gómez-Sanz E, Simón C, Ortega C, Gómez P, Lozano C, Zarazaga M, Torres C.Eight coagulase-positive staphylococci from equines with different pathologies obtained between 2005 and 2011 were investigated. Isolates were characterized by different molecular techniques (spa-, agr-, MLST), and clonal relatedness of strains was investigated by ApaI and SmaI PFGE. Anti-microbial resistance and virulence profiles were determined. Six isolates were identified as Staphylococcus aureus, and two as Staphylococcus pseudintermedius. Of these, four isolates were methicillin-resistant S. aureus (MRSA) ST398 and one S. pseudintermedius was mecA positive and typed as ST68. One MRSA ...
Pusterla N, Byrne BA, Hodzic E, Mapes S, Jang SS, Magdesian KG.A quantitative real-time (RT)-PCR assay was developed to detect Salmonella spp. in the feces of 911 equine species admitted to a veterinary hospital. Fresh feces and feces enriched for 24h in selenite broth were assessed by conventional culture and by RT-PCR targeting the Salmonella invA gene. The detection limit for the RT-PCR assay was 3 and 10 organisms, respectively, when spiked samples were purified from selenite broth and feces. The analytical specificity was 100% based on the detection of a panel of 40 salmonella serotypes from five serogroups and the lack of cross-reactivity with non-r...
Yildirim A, Okur M, Uslug S, Onder Z, Yetismis G, Duzlu O, Ciloglu A, Simsek E, Inci A.Horses might play an important role as reservoir hosts in the epidemiology of Enterocytozoon bieneusi, which is one of the most important zoonotic microsporidian pathogens, with a wide range of hosts. Nevertheless, limited information is available on the infection rates and genotypes of E. bieneusi in horses, and no data are available on the occurrence and molecular characteristics of E. bieneusi in horses in Turkey. We determined the prevalence of E. bieneusi among horses raised on farms from two provinces of Central Anatolia Region, by amplification of the partial small subunit ribosomal RNA...
Krajaejun T, Kittichotirat W, Patumcharoenpol P, Rujirawat T, Lohnoo T, Yingyong W.The oomycete Pythium insidiosum infects humans and animals worldwide, and causes the life-threatening condition, called pythosis. Most patients lose infected organs or die from the disease. Comparative genomic analyses of different P. insidiosum strains could provide new insights into its pathobiology, and can lead to discovery of an effective treatment method. Several draft genomes of P. insidiosum are publicly available: three from Asia (Thailand), and one each from North (the United States) and Central (Costa Rica) Americas. We report another draft genome of P. insidiosum isolated from Sout...
Verheyen K, Newton JR, Talbot NC, de Brauwere MN, Chanter N.Three protracted outbreaks of strangles were investigated using endoscopic examination and a total of 14 asymptomatic carriers of Streptococcus equi were identified of which 13 showed evidence of carriage in the guttural pouch. Treatment was initiated to eliminate S. equi colonisation since these animals posed an infectious risk to susceptible horses. Two further horses were referred to us with severe guttural pouch pathology and from which S. equi was cultured, and treatment of these cases is also described. Treatment in the first instance was directed towards removal of gross guttural pouch ...
Duggan JM, Coates DM, Ulaeto DO.Venezuelan equine encephalomyelitis (VEE) virus is an important human and veterinary pathogen of Central and South America. The virus can cause widespread epidemics, affecting hundreds of thousands of horses, and thousands of humans. Detection of the virus early in infection and in mosquito populations may allow epidemics to be predicted such that suitable prophylaxis, such as vaccination, can be used to reduce disease severity and transmission. The sensitivity and specificity of current immunoassays, based on conventional monoclonal and polyclonal antibodies, needs to be improved for the diag...
Muscatello G, Gilkerson JR, Browning GF.Virulent Rhodococcus equi causes pyogranulomatous bronchopneumonia in foals. The route of infection of foals has been considered to be inhalation of aerosolized bacteria from soil that is contaminated with equine feces. Thus, disease caused by R. equi has been regarded as an opportunistic infection of environmental origin and not a contagious disease. In this study, we report the exhalation of virulent R. equi from the respiratory tract of naturally infected foals. A handheld air-monitoring system was used to recover virulent R. equi from the exhaled breath of foals, and the concentration of v...
Songsermsakul P, Böhm J, Aurich C, Zentek J, Razzazi-Fazeli E.Concentration profile of zearalenone (ZON) and its metabolites in plasma, urine and faeces samples of horses fed with Fusarium toxin-contaminated oats is described. In plasma, β-zearalenol (β-ZOL) was detected at high levels on day 10 of the study (3.21-6.24 μg/l). β-Zearalenol and α-zearalenol were the major metabolites in urine. Zearalenone, α-ZOL and β-ZOL were predominantly found in faeces. Zearalanone could also be detected in urine (1.34-5.79 μg/l) and faeces (1 μg/kg). The degree of glucuronidation was established in all sample types, approximately 100% in urine and plasm...
de Oliveira PB, Harvey TV, Fehlberg HF, Rocha JM, Martins TF, da Acosta ICL, Labruna MB, Faccini JLH, Albuquerque GR.Tick-borne spotted fever in Brazil is known to be caused by two agents, Rickettsia rickettsii and Rickettsia parkeri. Nothing was known about these agents in one area of the Atlantic rainforest biome of Bahia state, where during March to June 2016, 356 rural dogs and 69 horses were sampled and their sera were processed through indirect immunofluorescence assay against antigens of R. rickettsii, R. parkeri, Rickettsia amblyommatis and Rickettsia bellii. Ticks collected from these dogs and horses were molecularly tested for the presence of rickettsial DNA. Overall, 16.4% (58/356) dogs and 24.6% ...
Lian WC, Liau MY, Mao CL.Nervous disorders were found in two horses and verified as aseptic encephalitis by necropsy in the summer of 2000. To investigate agents that affected the horses, diagnostic procedures involving virus isolation, neutralization test and reverse transcription-polymerase chain reaction (RT-PCR) were performed. We intracranially inoculated litters of suckling mice with tissues suspected of containing aseptic encephalitis, including cerebrum, cerebellum, brain stem, thalamus, and cerebrospinal fluids; the mice were then observed for 14 days. Neutralizing antibodies against Japanese encephalitis (JE...
Read JE, Cabrera-Sharp V, Offord V, Mirczuk SM, Allen SP, Fowkes RC, de Mestre AM.Equine chorionic girdle trophoblast cells play important endocrine and immune functions critical in supporting pregnancy. Very little is known about the genes and pathways that regulate chorionic girdle trophoblast development. Our aim was to identify genes and signalling pathways active in vivo in equine chorionic girdle trophoblast within a critical 7-days window. We exploited the late implantation of the equine conceptus to obtain trophoblast tissue. An Agilent equine 44K microarray was performed using RNA extracted from chorionic girdle and chorion (control) from equine pregnancy days 27, ...
