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.
Falcão MVD, Silveira PPM, Santana VLA, da Rocha LO, Chaves KP, Mota RA.Burkholderia (B.) mallei is the causative agent of glanders in Equidae. This study describes the first record of the Turkey 10 strain of B. mallei in glanderous horses in Northeastern of Brazil. This description should contribute to the future actions of diagnosis, control, and eradication of this disease in Brazil.
Uchida-Fujii E, Niwa H, Kinoshita Y, Nukada T.Actinobacillus species are known to be pathogenic to horses. To clarify etiological agents of actinobacillosis in Japanese adult horses, 27 isolates from Japanese Thoroughbred racehorses putatively identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry as Actinobacillus were further identified by PCR of the A. equuli toxin gene, by CAMP test, and by 16S rRNA sequencing analysis. Actinobacillus equuli subsp. haemolyticus was isolated most frequently (16/27) and was related to respiratory infections. Actinobacillus equuli subsp. equuli (4/27) was isolated from...
Pusterla N, Bowers J, Barnum S, Hall JA.The objective of this study was to detect Streptococcus equi subspecies equi (S. equi) (Lactobacillales: Streptococcaceae) using quantitative polymerase chain reaction (qPCR) in flies collected from a farm with a documented outbreak of strangles. A total of 1856 face flies [Musca autumnalis (Diptera: Muscidae)] were collected using conventional fly traps. The flies were processed for nucleic acid purification and tested for the presence of S. equi by qPCR. A total of 10/1856 flies (0.54%) tested qPCR-positive for S. equi. The results may implicate the presence of face flies as a risk factor...
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% ...
Von Dollen KA, Jones M, Beachler T, Harris TL, Papich MG, Lyle SK, Bailey CS.The use of antimicrobials for the management of equine uterine disease is commonplace, with antibiotic selection generally based on empirical evidence or in vitro sensitivity results. However, the potential disconnect between these laboratory results and clinical efficacy in the mare raises concern for antibiotic failure and subsequent development of resistant organisms. In this work, we attempt to bridge this gap by using an ex vivo model of the equine postpartum uterus to quantitatively evaluate the antimicrobial activity of two commonly used antibiotic treatments in the mare (ceftiofur an...
Vázquez-Boland JA, Meijer WG.Rhodococcus equi is the only recognized animal pathogenic species within an extended genus of metabolically versatile Actinobacteria of considerable biotechnological interest. Best known as a horse pathogen, R. equi is commonly isolated from other animal species, particularly pigs and ruminants, and causes severe opportunistic infections in people. As typical in the rhodococci, R. equi niche specialization is extrachromosomally determined, via a conjugative virulence plasmid that promotes intramacrophage survival. Progress in the molecular understanding of R. equi and its recent rise as a nove...
Al-Kass Z, Eriksson E, Bagge E, Wallgren M, Morrell JM.Although artificial insemination (AI) was developed as a means of controlling disease transmission, pathogens can still be transmitted to females in semen used for AI. In addition, bacteria can cause deterioration in sperm quality during storage. Semen becomes contaminated by the male's normal bacterial flora as it passes out of the reproductive tract but potential pathogens may also contaminate the semen. Therefore, semen samples from stallions to be used for AI are tested before the breeding season to minimize transmission of pathogens to inseminated mares. In Sweden, semen samples are teste...
Borkent D, Smith S, Dixon PM.Peripheral caries (PC) has recently been shown to affect over half of UK and Australian horses. Objective: To examine affected cheek teeth histologically and ultrastructurally, to assess the possible route(s) of carious infection into the dental tissues and to further describe the pathological changes in affected teeth. Methods: Descriptive pathological study. Methods: Four control and 16 cheek teeth with different grades of PC were examined grossly, histologically and by electron microscopy. Results: Cariogenic bacteria from plaque entered peripheral cementum perpendicular to the sides of tee...
Van Cleemput J, Poelaert KCK, Laval K, Van den Broeck W, Nauwynck HJ.The horse's respiratory tract daily encounters a plethora of respirable hazards including air pollutants, mycotoxins and airborne pathogens. To date, the precise effect of air pollution and mycotoxins on respiratory epithelial integrity and subsequent pathogen invasion in the horse has not been studied. Here, diesel exhaust particles (DEP) and three major mycotoxins (deoxynivalenol [DON], aflatoxin B1 [AFB1] and fumonisin B1 [FB1]) were applied to the apical surfaces of both ex vivo respiratory mucosal explants and in vitro primary equine respiratory epithelial cells (EREC) cultivated at the a...
Yang J, Wang Y, Cui X, Zhang Y, Yu Z.Huge numbers of microorganisms reside in livestock faeces and constitute one of the most complex microbial ecosystems. Here, faecal microbial communities of three typical livestock in Xilingol steppe grassland, i.e. sheep, cattle, and horse, were investigated by Illumina MiSeq sequencing and quantitative real-time polymerase chain reaction (qPCR). Firmicutes and Bacteroidetes comprised the majority of bacterial communities in three livestock faeces. Sordariomycetes, Leotiomycetes, and Dothideomycetes were dominant in fungal communities, as well as Methanobacteria and Methanomicrobia were domin...
Smith RM, Bhoora RV, Kotzé A, Grobler JP, Lee Dalton D.Translocation of animals in fragmented habitats is an important means of dispersal and gene flow, however, the movement of animals has led to the spread of various diseases globally and wildlife are often the reservoirs of these diseases. Currently, Cape mountain zebra are translocated within South Africa as a management method for augmentation of isolated and fragmented populations. The movement of pathogens due to translocations in local regions have gone largely unchecked, particularly where there may still be isolated regions that can be negatively affected. Equine piroplasmosis is a tick-...
Kasuya K, Tanaka N, Oshima F, Fujisawa N, Saito M, Tagami K, Niwa H, Sasai K.Strangles is a commonly diagnosed and important infectious disease of equids worldwide, caused by Streptococcus equi subsp. equi. We determined the SeM genotypes of S. equi isolated from imported horses at the Japanese border within the past 8 years, which allowed us to classify 12 strains isolated from these horses from each exporter into four allelic groups. These alleles were different from the alleles of past isolates found in Japan. Furthermore, four strains classified into the same allele were isolated from horses from one exporter over several years. In this study, S. equi isolates from...
Xia Y, Qin S, Shen Y.In this study, we isolated four Weissella confusa strains from the healthy horse feces to test their potential as equine probiotics. The identification and characteristics of these isolates were determined as per standard methods. Resistance and susceptibility of the isolated strains were tested to low pHs, different heat treatments, commonly used antibiotics and against the pathogenic strains of Salmonella, Pasteurella, Staphylococcus aureus, and Escherichia coli. After 3 h cultural in different pH medium, the 4 strains still had a certain amount of survival above pH 3.0. WH2 and WH4 were s...
Sanz MG, Bradway DS, Horohov DW, Baszler TV. is the most common cause of pneumonia in young foals. Pneumonic foals are an important source of environmental contamination as they shed higher amounts of in their faeces than unaffected foals. As -specific hyperimmune plasma (HIP) lessens clinical pneumonia, we hypothesise that its use would result in decreased faecal shedding of by foals. Neonatal foals were either given HIP (n=12) or nothing (n=9, control) shortly after birth and were then experimentally infected with Faeces were collected before and on weeks 2, 3, 5 and 7 after infection. Presence of virulent was tested using qPCR. T...
Waqar N, Amin Q, Munir T, Ikram MS, Shahzad N, Mirza A, Ali A, Arshad MI.The present study aimed at investigating the percent prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in equines and associated personnel. A total of 150 swabs of equines and 50 nasal swab samples of associated personnel were collected. These samples were processed in mannitol salt broth for enrichment. A total of 175 nasal swab samples changed the broth color from pink to yellow which were detected as samples containing S. aureus. These samples were processed further on specific media, namely mannitol salt agar, Staph-110, and blood agar, for phenotypic and Gram's staining-bas...
Santodomingo A, Sierra-Orozco K, Cotes-Perdomo A, Castro LR.Horses are among the domestic animals that closely interact with humans and are highly parasitized by ticks, which are the primary vectors of zoonoses. As horses in Tayrona National Natural Park (PNNT) are used as a means of transporting goods, luggage and people, they are in constant contact with wild animals, workers and tourists from different countries. These factors increase the transmission risk of hemoparasites. The purpose of this study was to determine the presence of Rickettsia sp., Anaplasma sp., and Theileria sp., in horse ticks in this protected area using conventional PCR. We col...
Willingham-Lane JM, Berghaus LJ, Berghaus RD, Hart KA, Giguère S. is a leading cause of severe pneumonia in foals. Standard treatment is dual antimicrobial therapy with a macrolide and rifampin, but the emergence of macrolide- and rifampin-resistant isolates is an increasing problem. The objective of this study was to determine the effect of macrolide and/or rifampin resistance on fitness of Three unique isogenic sets were created, each consisting of four strains, as follows: a susceptible parent isolate, strains resistant to macrolides or rifampin, and a dual macrolide- and rifampin-resistant strain. Each isogenic set's bacterial growth curve was genera...
Duchesne R, Castagnet S, Maillard K, Petry S, Cattoir V, Giard JC, Leon A.This study aimed to analyse antimicrobial susceptibility evolution of equine pathogens isolated from clinical samples from 2006-2016. A collection of 25 813 bacterial isolates was studied, clustered according to their origins (respiratory tract, cutaneous, genital and other), and analysed for their antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.6%), Escherichia coli (20.0%), Staphylococcus aureus (7.8%), Pseudomonas aeruginosa (4.0%), Enterobacter spp. (3.4%), Klebsiella pneumoniae (2.4%), and Rhodococcus equi ...
Jackson K, Kelty E, Staszyk C, Tennant M.Peripheral caries may cause significant oral pain and pathology and is very prevalent within the Western Australia horse population. Associations with periodontal disease have been indicated; however, further work is needed to assess the anatomical and histological aspects of the conditions, to better understand the pathophysiology. Objective: To assess the anatomical and histopathological changes associated with equine cheek teeth peripheral caries and disease of the periodontium to better understand the pathogenesis and any association between the conditions. Methods: Cross-sectional epidemi...
Hansford KM, Carter D, Gillingham EL, Hernandez-Triana LM, Chamberlain J, Cull B, McGinley L, Paul Phipps L, Medlock JM.During September 2018, a tick was submitted to Public Health England's Tick Surveillance Scheme for identification. The tick was sent from a veterinarian who removed it from a horse in Dorset, England, with no history of overseas travel. The tick was identified as a male Hyalomma rufipes using morphological and molecular methods and then tested for a range of tick-borne pathogens including; Alkhurma virus, Anaplasma, Babesia, Bhanja virus, Crimean-Congo Haemorrhagic fever virus, Rickettsia and Theileria. The tick tested positive for Rickettsia aeschlimannii, a spotted fever group rickettsia li...
Petry S, Py JS, Wilhelm A, Duquesne F, Bäyon-Auboyer MH, Morvan H, Gassilloud B.Misidentification between Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), and Taylorella asinigenitalis is observed by the gold standard culture method. The performance of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for Taylorella species identification was evaluated using 85 T. equigenitalis and 28 T. asinigenitalis strains selected on the basis of multilocus sequence typing data. Seven of the T. equigenitalis and 9 of the T. asinigenitalis strains were used to generate in-house reference spectra to expand ...
Léveillé AN, Bland SK, Carlton K, Larouche CB, Kenney DG, Brouwer ER, Lillie BN, Barta JR.Species in the genus Klossiella Smith and Johnson, 1902 are unique among the suborder Adeleorina because they are monoxenous in mammals exclusively, whereas all other reported members of the Adeleorina use invertebrates as definitive hosts. Unlike other coccidia, all members of the Adeleorina undergo syzygy, the association of microgamonts and macrogamonts before maturation to gametes and syngamy. After fertilization, many members of the Adeleorina produce thin-walled polysporocystic oocysts. Despite being biologically similar to other members of the Adeleorina, the phylogenetic placement of t...
Pringle J, Venner M, Tscheschlok L, Bächi L, Riihimäki M.After strangles outbreaks, Streptococcus equi ssp. equi (S. equi) can persist in clinically normal silent carriers for months to years. Two naturally occurring outbreaks of strangles with 53 and 100% morbidity, respectively, were followed longitudinally to assess occurrence of carrier state and optimal detection methods Outbreak A involved 98 yearling warmbloods, and outbreak B 38 mature Icelandic horses. Fully recovered horses were sampled at least 6 months after index cases using nasal swabs (one sampling occasion only) nasopharyngeal lavage and guttural pouch visualisation and lavages for c...
Shchit IY, Ignatov KB, Biketov SF.Results of detection of Burkholderia mallei and Burkholderia pseudomallei DNA strains by LAMP (Loop-mediated Isothermal Amplification) and Real Time PCR are shown. It has been revealed that, in Real Time PCR, primers steadily detected DNA of those microorganism for the sequences of which they were designed. The above mentioned primers did not detect DNA of heterologous strains. During LAMP method no set of primers showed high analytical sensitivity and specificity. Primers did not detected DNA of all the strains under research to target genes of which they were not intended, but they were capa...
de Lagarde M, Larrieu C, Praud K, Schouler C, Doublet B, Sallé G, Fairbrother JM, Arsenault J.Although antimicrobial resistance is increasingly common in equine medicine, molecular and epidemiological data remains scarce. Objective: We estimated the prevalence of, and risk factors for, shedding of multidrug resistant (MDR), extended spectrum β-lactamase (ESBL)-producing, and AmpC β-lactamase-producing, or some combination of these in Escherichia coli in horses in France. We characterized ESBL/AmpC isolates for antimicrobial susceptibility and the presence of virulence and ESBL/AmpC-associated resistance genes. Methods: Fecal samples from healthy adult horses at 41 premises were colle...
Seo MG, Ouh IO, Choi E, Kwon OD, Kwak D.The identification and characterization of pathogenic and zoonotic tick-borne diseases like granulocytic anaplasmosis are essential for developing effective control programs. The differential diagnosis of pathogenic Anaplasma phagocytophilum and non-pathogenic A. phagocytophilum-like Anaplasma spp. is important for implementing effective treatment from control programs. The objective of the present study was to investigate the prevalence of Anaplasma spp. in horses in Korea by nucleotide sequencing and restriction enzyme fragment length polymorphism assay. Of the 627 horses included in the stu...
McCoy AM, Smith RL, Secor EJ, Roady PJ.To determine the influence of tissue preparation and long-term storage methods on structural integrity and risk of bacterial contamination of equine amnion. Methods: Prospective experimental investigation SAMPLE POPULATION: Amniotic membranes from 8 healthy mares (n = 440 tested samples). Methods: Samples for baseline bacteriology and histology were taken after removal of debris. The remaining tissue was divided and processed with 0.05% chlorhexidine or 2% iodine/0.25% acetic acid. Processed amnion samples were assigned to 1 of 9 combinations of storage media (saline, chlorhexidine, acetic...
Scare JA, Steuer AE, Shaffer CL, Slusarewicz P, Mousley A, Nielsen MK.In vitro maintenance of helminth parasites enables a variety of molecular, pharmaceutical and immunological analyses. Currently, the nutritional and environmental in vitro requirements of the equine ascarid parasite, Parascaris spp., have not been determined. Additionally, an objective method for assessing viability of Parascaris spp. intestinal stages does not exist. The purpose of this study was to ascertain the in vitro requirements of intestinal stages of Parascaris spp., and to develop a viability assessment method. A total of 1045 worms were maintained in a total of 212 cultures. Worms o...
More SN, Hernandez O, Castleman WL.Rhinitis and sinusitis caused by fungal pathogens were studied in biopsy samples submitted from 52 horses distributed throughout subtropical and tropical regions of Florida. Methods included routine histopathology as well as polymerase chain reaction (PCR) with panfungal/panoomycete primers and DNA sequencing on extracted DNA (DNA barcoding). Granulomatous, pyogranulomatous, and fibrinopurulent lesions in nasal and sinus mucosa were associated with signs of upper airway obstruction and noise as well as nasal discharge. Morphologic and histochemical assessment of cases identified 31 cases of zy...
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...
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, ...
