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.
Bustos CP, Leiva CL, Gambarotta M, Guida N, Chacana PA.Equine salmonellosis is caused by several Salmonella serotypes, including Salmonella Newport, which cause enterocolitis and diarrhea. Treatment usually includes the administration of antibiotics. However, since multidrug-resistant Salmonella is commonly detected, alternative options to control the pathogen are needed. One of these options is the use of specific egg yolk antibodies (IgY) for passive immunotherapy. Thus, the aim of our work was to produce IgY antibodies against an equine S. Newport strain and assess their in vitro inhibitory activity. To this end, laying hens were immunized with...
Stewart HL, Engiles JB, Richardson DW, Levine DG.To describe the bactericidal and fungicidal properties of a 0.0005% chlorhexidine (CHD) solution potentiated with EDTA-Tris buffers (CHD-EDTA-Tris) and evaluate the safety of 0.0005% CHD-EDTA-Tris in the upper respiratory tract (URT) of normal horses. Methods: Clinical, prospective study. Methods: Eight healthy, skeletally mature horses. Methods: In vitro-serial dilutions of CHD-EDTA-Tris and EDTA-Tris alone were evaluated for bactericidal and fungicidal activity against Aspergillus fumigatus, Escherichia coli, Staphylococcus aureus, Streptococcus equi subspecies ssp. equi, Streptococcus equi ...
Uiterwijk M, Ibáñez-Justicia A, van de Vossenberg B, Jacobs F, Overgaauw P, Nijsse R, Dabekaussen C, Stroo A, Sprong H.Ticks of the genus Hyalomma, which are vectors for several tick-borne diseases, are occasionally found in areas outside their endemic range including northern parts of Europe. The objective of this study was to analyse adult Hyalomma ticks that were recently found in the Netherlands. Methods: Hyalomma ticks were morphologically identified. Cluster analysis, based upon sequence data (cox1 barcoding) for molecular identification, and pathogen detection were performed. Additionally, a cross-sectional survey of horses was conducted to actively search for Hyalomma ticks in summer 2019. Analysis of...
Ebani VV, Nardoni S, Bertelloni F, Pollera C, Pistelli L, Mancianti F.The aim of the present study, the first to test clinical equine isolates, was to evaluate the antimicrobial activity of commercial essential oils (EOs) obtained from and against spp., spp., and spp. previously isolated from uteri of mares with reproductive disorders. showed the best antibacterial activity against all the selected agents, with MICs ranging from 0.07 mg/mL for subsp. to 0.29 mg/mL versus sp. and spp. isolates and versus and spp., with MICs of 0.46 mg/mL and 1.86 mg/mL, respectively. EOs showed good antibacterial activity with MICs ranging from 0.07 mg/mL ...
Mitchell S, Bull M, Muscatello G, Chapman B, Coleman NV.Antibiotic resistance in bacterial pathogens is a growing problem for both human and veterinary medicine. Mobile genetic elements (MGEs) such as plasmids, transposons, and integrons enable the spread of antibiotic resistance genes (ARGs) among bacteria, and the overuse of antibiotics drives this process by providing the selection pressure for resistance genes to establish and persist in bacterial populations. Because bacteria, MGEs, and resistance genes can readily spread between different ecological compartments (e.g. soil, plants, animals, humans, wastewater), a "One Health" approach is need...
Zhu Y, Chen S, Yi Z, Holyoak R, Wang T, Ding Z, Li J. subsp. equi () is the pathogen causing strangles, a highly infectious disease that can affect equids including donkeys of all ages. It can persistently colonize the upper respiratory tract of animals asymptomatically for years, which serves as a source of infection. Several strangles outbreaks have been reported in the donkey industry in China in the last few years and pose a great threat to health, production, and the welfare of donkeys. Nasopharyngeal swab samples for culture and PCR are used widely in strangles diagnosis. Additionally, microbiomes within and on the body are essential to ho...
Lacerda MDSC, Wilson TM, Argenta VLS, de Araújo Pinto ÉG, E Macêdo JTSA, Soto-Blanco B, Keller KM, Ocampos Pedroso PM, Câmara ACL.The present report describes the clinical and pathological changes induced by the consumption of oats contaminated with Crotalaria spectabilis seeds by horses. Eighty horses were exposed to oats containing 10 g/kg of C. spectabilis seeds with 0.46% pyrrolizidine alkaloids, and 21 horses died within a 6-month period. Clinical signs included jaundice, apathy, a hypotonic tongue, ataxia, hyporexia, weight loss, aimless wandering, violent behavior, and proprioceptive deficits. Pathological findings were predominant in the liver and included periportal bridging fibrosis, megalocytosis, centrilobul...
Allegro AR, Barhoumi R, Bordin AI, Bray JM, Cohen ND.Rhodococcus equi is a soil saprophytic bacterium and intracellular pathogen that causes pneumonia in foals. Strains of R. equi that are virulent in foals contain a plasmid that encodes a virulence-associated protein A (VapA) necessary for replication in macrophages. Because other intracellular pathogens survive and replicate inside amoebae, we postulated that the VapA-bearing plasmid (pVAPA) confers a survival advantage for R. equi against environmental predators like amoebae. To test this hypothesis, we compared phagocytosis by and survival in Acanthamoeba castellanii of isogenic strains of p...
Drážovská M, Vojtek B, Mojžišová J, Koleničová S, Koľvek F, Prokeš M, Korytár Ľ, Csanady A, Ondrejková A, Vataščinová T, Bhide MR.Anaplasma phagocytophilum is the causative agent of granulocytic anaplasmosis. It affects humans and several wild and domesticated mammals, including horses. The aim of our study was a preliminary survey of the occurrence of these re-emerging pathogens in horses in Slovakia. The sera from 200 animals of different ages and both sexes were tested for the presence of A. phagocytophilum antibodies by indirect immunofluorescence assay. Subsequently, detection of the 16S rRNA gene fragment of A. phagocytophilum was attempted by polymerase chain reaction (PCR) in each blood sample. Our results confir...
Kang HW, Lee EY, Lee KK, Ko MK, Park JY, Kim YH, Lee K, Choi EJ, Kim J, So B, Park CK, Jeoung HY.Equine herpesvirus-1 (EHV-1) is an important pathogen in horses. It affects horses worldwide and causes substantial economic losses. In this study, for the first time, we characterized EHV-1 isolates from South Korea at the molecular level. We then aimed to determine the genetic divergences of these isolates by comparing them to sequences in databases. In total, 338 horse samples were collected, and 12 EHV-1 were isolated. We performed ORF30, ORF33, ORF68, and ORF34 genetic analysis and carried out multi-locus sequence typing (MLST) of 12 isolated EHV-1. All isolated viruses were confirmed as ...
Dayaram A, Seeber PA, Greenwood AD.Equine herpesviruses (EHV) are a major health concern for domestic and wild equids and represent one of the most economically important disease agents of horses. Most known EHVs are transmitted directly between individuals as a result of direct exposure to exudates and aerosols. However, accumulating evidence suggests that environmental transmission may play a role including air, water, and fomites. Here, we reviewed studies on environmental stability and transmission of EHVs, which may influence viral dynamics and the use of environmental samples for monitoring EHV shedding.
Noll CV, Kilcoyne I, Nieto JE, Thio T, Byrne BA.To determine the ability of 0.2% polyhexamethylene biguanide (PHMB)-impregnated gauze to inhibit the growth of bacteria isolated from equine infected sites. Methods: In vitro study. Methods: Nine bacterial isolates were obtained from cultures submitted from equine patients presenting with penetrating injuries of the hoof (n = 4), septic osteitis (n = 1), synovial sepsis (n = 1), wounds (n = 2), and incisional infection following laparotomy (n = 1). Two standardized strains were also included. A standard inoculum of each isolate was placed on 12 Muller-Hinton agar plates. Squares (2.5 cm ×...
Reshadi P, Heydari F, Ghanbarpour R, Bagheri M, Jajarmi M, Amiri M, Alizade H, Badouei MA, Sahraei S, Adib N.Transmission of antimicrobial resistant and virulent Escherichia coli (E. coli) from animal to human has been considered as a public health concern. This study aimed to determine the phylogenetic background and prevalence of diarrheagenic E. coli and antimicrobial resistance in healthy riding-horses in Iran. In this research, the genes related to six main pathotypes of E. coli were screened. Also, genotypic and phenotypic antimicrobial resistance against commonly used antibiotics were studied, then phylo-grouping was performed on all the isolates. Results: Out of 65 analyzed isolates, 29.23...
Bernardino P, James K, Barnum S, Corbin R, Wademan C, Pusterla N.Equine rhinitis B virus (ERBV) has been given little attention by practitioners compared to other respiratory viruses, mainly because of the lack of diagnostic modalities and association with clinical disease. The objective of the study was to determine the frequency of detection of ERBV in nasal secretions from 6568 horses with acute onset of respiratory signs. ERBV-positive qPCR results from nasal secretions submitted to a molecular diagnostic laboratory from 2013 to 2019 were reviewed. A total of 333 ERBV qPCR-positive samples (5.1%) were detected with increasing yearly frequency since the ...
Adams RJ, Mollenkopf DF, Mathys DA, Whittle A, Ballash GA, Mudge M, Daniels JB, Barr B, Wittum TE.To estimate the prevalence of extended-spectrum cephalosporin-, carbapenem-, and fluoroquinolone-resistant bacteria of the family Enterobacteriaceae in the feces of hospitalized horses and on hospital surfaces. Methods: Fecal and environmental samples were collected from The Ohio State University Galbreath Equine Center (OSUGEC) and a private referral equine hospital in Kentucky (KYEH). Feces were sampled within 24 hours after hospital admission and after 48 hours and 3 to 7 days of hospitalization. Methods: Fecal and environmental samples were enriched, and then selective media were inoculate...
Isola M, Piccinotti C, Magro M, Fasolato L, Vianello F, Menandro ML, Memarian P, Rossi M, Falomo ME.The presence of bacteria of various origins on horse hoofs enables the onset of infections following trauma or even post-surgical wounds. Thus, the analysis of new antibacterial substances is of fundamental importance. In this study, the antibacterial efficacy of Iron Animals (IA), a stable colloidal suspension of iron oxide, organic acids, and detergents, was tested in vitro and in vivo. In vitro assays were performed to test the unspecific inhibitory effect of IA on both gram-positive and gram-negative bacteria monitoring the microorganism growth by spectrophotometry (optical density OD600) ...
Mitchell C, Steward KF, Charbonneau ARL, Walsh S, Wilson H, Timoney JF, Wernery U, Joseph M, Craig D, van Maanen K, Hoogkamer-van Gennep A, Leon A....The equine disease strangles, which is characterized by the formation of abscesses in the lymph nodes of the head and neck, is one of the most frequently diagnosed infectious diseases of horses around the world. The causal agent, subspecies , establishes a persistent infection in approximately 10 % of animals that recover from the acute disease. Such 'carrier' animals appear healthy and are rarely identified during routine veterinary examinations pre-purchase or transit, but can transmit to naïve animals initiating new episodes of disease. Here, we report the analysis and visualization of...
Weese JS, Slovis N, Rousseau J.Understanding the epidemiology of Clostridium difficile is important for the development and assessment of infection prevention and control practices, as well as surveillance methods and interpretation of diagnostic testing results. Objective: Our objective was to longitudinally evaluate C. difficile shedding in neonatal foals and mares admitted to a referral hospital neonatal intensive care unit. Methods: Foals admitted to a neonatal intensive care unit, along with their dams. Methods: Rectal swabs were collected from mares and foals at admission, and then approximately every 3 days, when p...
De Clercq E, Den Hondt S, De Baere C, Martens AM.To compare the effect of multiple wound dressings on microbial growth in a perfused equine wound model. Methods: Abdominal musculocutaneous flaps from 16 equine cadavers. Methods: 8 full-thickness skin wound covered were created in each flap. Tissues were perfused with saline (0.9% NaCl) solution. Wounds were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa (106 CFUs), incubated, and covered with a dressing containing activated charcoal, boric acid, cadexomer iodine, calcium alginate, manuka honey, nanoparticle silver, or polyhexamethylene biguanide ...
Bogdan AM, Ionita M, Mitrea IL.The purpose of this study was to investigate the seroprevalence of selected tick-borne-pathogens (TBPs) among Romanian horses. For this, a total of 223 animals originating from north, central, and southeast Romania, including horses from stud farms ( = 118) and working horses ( = 105), were tested using a commercial rapid ELISA-based test. Overall, 10.3% (95% confidence interval (CI): 6.7-15.1%) of the tested horses were seropositive for antibodies (Ab) against Additionally, 18.8% (95% CI: 13.9-24.6%) and 0.5% (95% CI: 0.01-2.5%) of horses were seropositive for Ab against sensu lato and spp...
Kamran K, Ali A, Villagra C, Siddiqui S, Alouffi AS, Iqbal A.Zoonotic diseases are significant public health issues. There is an urgent need to focus our efforts on the development of strategies that prevent and control potential arthropod vector-borne pathogens. Hard ticks transmit a variety of viral, bacterial and protozoan pathogens to their vertebrate hosts. This is becoming of more concern, as anthropogenic alterations of the environment may unleash the spread of tick-borne diseases throughout the world. Developing countries that are highly dependent on the livestock economy are a hot spot for tick-borne infectious diseases. In this work, through a...
Álvarez-Narváez S, Giguère S, Cohen N, Slovis N, Vázquez-Boland JA.Multidrug resistance has been detected in the animal and zoonotic human pathogen Rhodococcus equi after mass macrolide/rifampin antibioprophylaxis in endemically affected equine farms in the United States. Multidrug-resistant (MDR) R. equi emerged upon acquisition of pRERm46, a conjugative plasmid conferring resistance to macrolides, lincosamides, streptogramins, and, as we describe, tetracycline. Phylogenomic analyses indicate that the increasing prevalence of MDR R. equi since it was first documented in 2002 is caused by a clone, R. equi 2287, attributable to coselection of pRErm46 with a ch...
Romero-Salas D, Solis-Cortés M, Zazueta-Islas HM, Flores-Vásquez F, Cruz-Romero A, Aguilar-Domínguez M, Salguero-Romero JL, de León AP....Equine piroplasmosis is a tropical parasitic disease caused by several intraerythrocytic members of the genera Babesia and Theileria. These pathogens are transmitted by multiple tick species and are considered as important exotic microorganisms in several countries. Equine piroplasmosis causes significant economic losses due to abortions, decreased activity and even death of equines, making surveillance of these infectious disease essential. In the northern and eastern parts of Mexico, few molecular and serological reports have been made on the presence and exposure of horse to these agents. F...
Gwee SXW, St John AL, Gray GC, Pang J.Dengue is a rapidly spreading mosquito-borne flavivirus infection that is prevalent in tropical and sub-tropical regions. Humans are known to be the main reservoir host maintaining the epidemic cycles of dengue but it is unclear if dengue virus is also maintained in a similar enzootic cycle. The systematic review was conducted in accordance to Cochrane's PRISMA recommendations. A search was done on PubMed, EMBASE, Scopus and Cochrane Library. Key data on animal dengue positivity was extracted and classified according to animal type and diagnostic modes. Of the 3818 articles identified, 56 arti...
Ferreira JC, Pires RH, Costa GBD, Carrijo BN, Guiotto FG, Rodrigues VS.The goal of the present study was to characterize the antimicrobial action of different ozone (O) presentations against Pythium insidiosum isolated from horses. In experiment 1, P. insidiosum was treated with ozonated distilled water, ozonated sunflower oils with distinct peroxide indexes or O gas (72 μg O mL). In experiment 2, samples were exposed one or three times to oxygen (O) or O gas (72 μg O mL; 30 min/day). In experiment 3, P. insidiosum was treated with different concentrations of O gas (Ø, 32, 52, or 72 μg O mL) for three days (30 min/day). In experiment 4, samples were ex...
Anis E, Ilha MRS, Engiles JB, Wilkes RP.Equine infectious disease outbreaks may have profound economic impact, resulting in losses of millions of dollars of revenue as a result of horse loss, quarantine, and cancelled events. Early and accurate diagnosis is essential to limit the spread of infectious diseases. However, laboratory detection of infectious agents, especially the simultaneous detection of multiple agents, can be challenging to the clinician and diagnostic laboratory. Next-generation sequencing (NGS), which allows millions of DNA templates to be sequenced simultaneously in a single reaction, is an ideal technology for co...
Springer A, Glass A, Topp AK, Strube C.Ticks transmit a variety of pathogens affecting both human and animal health. In temperate and cold regions of Europe (Western, Central, Eastern, and Northern Europe), the most relevant zoonotic tick-borne pathogens are tick-borne encephalitis virus (TBEV), Borrelia spp. and Anaplasma phagocytophilum. More rarely, Rickettsia spp., Neoehrlichia mikurensis, and zoonotic Babesia spp. are identified as a cause of human disease. Domestic animals may also be clinically affected by these pathogens, and, furthermore, can be regarded as sentinel hosts for their occurrence in a certain area, or even pla...
Schoster A, Amsler M, Kirchgaessner C, Saleh L, Schwarzwald C, Schmitt S.The optimal dosage regimen of gentamicin in horses is still under investigation. The objectives of this study were to determine gentamicin plasma concentrations in hospitalized horses treated with 10 mg/kg gentamicin (IV, q 24 h) and to determine whether a plasma concentration to minimum inhibitory concentration (MIC) ratio of 10:1 is reached for equine pathogens using this dose. Methods: Prospective clinical observational study; retrospective study on MICs of 131 gram-negative bacteria isolated from horses (2012-2015). Methods: University teaching hospital. Methods: Ninety-eight horses >...
Mar Htun Z, Laikul A, Pathomsakulwong W, Yurayart C, Lohnoo T, Yingyong W, Kumsang Y, Payattikul P, Sae-Chew P, Rujirawat T, Jaturapaktrarak C....Pythium insidiosum causes a life-threatening infection termed pythiosis in humans and other animals. The organism has been identified in tropical and subtropical environments worldwide. Since 1985, human pythiosis has been increasingly reported from Thailand. Seroprevalence studies estimated that 32,000 Thai people had been exposed to the pathogen. In 2018, the first animal pythiosis case in Thailand was diagnosed in a horse. Here, we investigated the seroprevalence of anti-P. insidiosum antibodies in the Thai equine population. Methods: We surveyed serum anti-P. insidiosum antibodies in 15...
Stout AE, Hofmar-Glennon HG, André NM, Goodman LB, Anderson RR, Mitchell PK, Thompson BS, Lejeune M, Whittaker GR, Goodrich EL.In the United States, horses are used for a variety of purposes including recreation, exhibition, and racing. As farm, performance, and companion animals, horses are a unique species from a zoonotic disease risk perspective, and the risks of subclinical infections spreading among horses can pose challenges. Using a nanoscale real-time PCR platform, we investigated the prevalence of 14 enteric pathogens, 11 genes, and 9 respiratory pathogens in fecal samples from 97 apparently healthy horses at a multi-day horse event. In addition, sugar flotation test was performed for fecal parasites. was c...
Narankhajid M, Yeruult C, Gurbadam A, Battsetseg J, Aberle SW, Bayartogtokh B, Joachim A, Duscher GG.Ticks are cosmopolitan vectors of numerous diseases, and detection of various pathogens in ticks can help to assess their distribution. In the current study, 528 adult ticks were collected from grazing animals or the ground in ten different Mongolian provinces. Dermacentor nuttalli constituted 76.1% of them and was found in all ecozones except the eastern desert. Dermacentor marginatus (8.3%), Dermacentor silvarum (1.1%) and Ixodes persulcatus (3.0%) were found in the northern forest areas and Hyalomma asiaticum (11.4%) only in the southern (semi-)desert. Of these, 359 ticks were subjected to ...
Banet-Noach C, Malkinson M, Brill A, Samina I, Yadin H, Weisman Y, Pokamunski S, King R, Deubel V, Stram Y.In November 1997, an outbreak of a neuroparalytic disease caused by West Nile (WN) virus was diagnosed in young goose flocks. Domestic geese were similarly affected in the late summer and fall of 1998, 1999, 2000 and 2001. WN viruses were also isolated from migratory and wild birds and horses in 1998-2001. A 1278 bp sequence of the envelope gene of 24 Israeli WN virus isolates was compared with those of seven isolates from Africa, Europe and New York. As a result, the Israeli isolates could then be grouped into two clusters. The 15 avian and three equine from 1997-2001 in the first cluster of ...
Simonato G, Danesi P, Frangipane di Regalbono A, Dotto G, Tessarin C, Pietrobelli M, Pasotto D.Animal-assisted interventions (AAIs) are based on the establishment of a therapeutic relationship between animals and beneficiaries that is certain to provide positive effects, while currently, it reads as if AAIs aim at exposing stakeholders to potential risk of infection. The surveillance of zoonotic pathogens is necessary for guaranteeing common health. This study investigated the presence of potentially zoonotic parasites, including dermatophytes, in animals involved in AAIs. Between 2015 and 2017, 190 animals (equids, dogs, cats, birds, rabbits, rodents, and goats) were investigated. Anam...
Meehan M, Nowlan P, Owen P.Cell-wall-associated proteins from Streptococcus equi subsp. equi, the causative agent of strangles, were analysed with a view to identifying a potential protective antigen. Preparations of these proteins, isolated from mutanolysin extracts of cell walls, were shown to contain one major high-M(r) protein species (apparent M(r) 220,000 and 550,000 when analysed by SDS-PAGE and gel-filtration chromatography, respectively). The high-M(r) protein bound horse fibrinogen and was purified under non-denaturing conditions using fibrinogen affinity chromatography. The fibrinogen-binding protein (FgBP) r...
Ren J, Prescott JF.An 81 kb virulence plasmid containing a pathogenicity island (PI) plays a crucial role in the pathogenesis of Rhodococcus equi pneumonia in foals but its specific function in virulence and regulation of plasmid-encoded virulence genes is unclear. Using a LacZ selection marker developed for R. equi in this study, in combination with an apramycin resistance gene, an efficient two-stage homologous recombination targeted gene mutation procedure was used to mutate three virulence plasmid genes, a LysR regulatory gene homologue (ORF4), a ResD-like two-component response regulator homologue (ORF8), a...
Nielsen CF, Reisen WK, Armijos MV, Maclachlan NJ, Scott TW.Although horse cases frequently are reported during West Nile virus (WNV) outbreaks, few investigations have focused on the epidemiology of this transmission. From April to October 2003 to 2005, mosquito abundance and infection were monitored 3 days per week at an equine research facility at the University of California, Davis. Thirty-two nonvaccinated horses enrolled as controls in a vaccine study were bled monthly, and their serum was tested for evidence of WNV infection by plaque reduction neutralization test (PRNT). In 2004, one positive Culex pipiens pool was associated with a single hors...
Klebanoff SJ, Agosti JM, Jörg A, Waltersdorph AM.Stimulated eosinophils release cytotoxic granule constituents, including eosinophil peroxidase (EPO) and a group of granule basic proteins (GBP). EPO reacts with H2O2 formed by the respiratory burst and a halide to form cytotoxic oxidants. The relative potency of the EPO-H2O2-halide system and the GBP is considered here. Horse eosinophils were induced to degranulate, the degranulation products were separated by chromatography on Sephadex G-50 and comparable volumes of the column fractions were tested for toxicity to Escherichia coli and the schistosomula of Schistosoma mansoni in the presence ...
Heidelberger M.Data accumulated over many years are brought together on cross-reactions of 46 among the more than 80 pneumococcal serological types, with the idea of correlating cross-reactions with the structures of the relevant type-specific capsular polysaccharides, insofar as these have been determined. The precipitin reaction was carried out with the polysaccharides and antibodies raised in horses, rabbits, and a mule. Quantitative values (micrograms of antibody nitrogen per milliliter of antiserum at 0 to 1 degree C) are given in many instances and discussed, together with arbitrary qualitative data, i...
Petinaki E, Spiliopoulou I.Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most virulent human pathogens and has also recently been recognized as such in the veterinary settings. Companion animals, including dogs, cats, horses, small exotic animals, wildlife animals, and livestock, may constitute a reservoir for MRSA transmission to humans and vice versa. The evolution, emergence, and risk factors for MRSA transmission among colonized or infected animals are reviewed in the present paper, and infection control practices are discussed.
Miller RI.Although 'phycomycosis' is a common disease of horses in northern Australia little is known about the causative fungi. In this paper the laboratory methods for diagnosis are described. These revealed 38 cases caused by Pythium sp. (Hyphomyces destruens), 6 cases caused by Basidiobolus haptosporus and 2 caused by Conidiobolus coronatus. Laboratory studies on the chemotatic behaviour of zoospores of Pythium sp. showed that they were strongly attracted to both animal hairs and plant tissue. Because of this behaviour a simple baiting method using human hair was used to trap the fungus from water s...
Donahue JM, Smith BJ, Redmon KJ, Donahue JK.A study was conducted to evaluate a recently available fluorescent antibody test (FAT) conjugate for the detection of leptospires in tissues of aborted and stillborn horses, to determine the leptospira antibody titers and compare serologic test results with FAT results, and to determine the prevalence of leptospira-induced abortions and stillbirths in the equine population of central Kentucky. From July 1, 1988 through June 30, 1989, 15 (2.5%) of 594 submissions (fetuses, stillborn foals, and/or placentas) were diagnosed as leptospirosis by the FAT (14 of 15 tested) and/or microscopic agglutin...
Werner LA, Hardy J, Bertone AL.To compare intra-articular (IA) and bone gentamicin concentrations achieved after intra-articular administration or regional intravenous perfusion (RIP). Methods: Experimental study. Methods: Twelve healthy adult horses. Methods: Horses were assigned to 2 treatment groups (n = 6/group): Group 1, 1 g gentamicin administered simultaneously in both left and right metacarpophalangeal joints and group 2, 1 g gentamicin administered simultaneously in both left and right lateral palmar veins. Serum, synovial fluid, and bone biopsy specimens were collected. Gentamicin concentrations were determined by...
Taniguchi A, Fukushi H, Matsumura T, Yanai T, Masegi T, Hirai K.Pathogenicity of equine herpesvirus 9 (EHV-9), a new type of equine herpesvirus isolated from Gazella thomsoni, in horses was investigated by intranasal inoculation of EHV-9 (10(7) pfu) to two conventionally reared 8-months old half-bred weanling horses. Fever higher than 39 degrees C was recorded. Virus was recovered from nasal swabs and peripheral blood mononuclear cells. Both horses developed neutralizing antibody to EHV-9. Perivascular infiltration of mononuclear cells and glial reaction were found in the olfactory and limbic systems. The results suggested that EHV-9 has a pathogenicity in...
Rodriguez C, Taminiau B, Brévers B, Avesani V, Van Broeck J, Leroux AA, Amory H, Delmée M, Daube G.Clostridium difficile has been identified as a significant agent of diarrhoea and enterocolitis in both foals and adult horses. Hospitalization, antibiotic therapy or changes in diet may contribute to the development of C. difficile infection. Horses admitted to a care unit are therefore at greater risk of being colonized. The aim of this study was to investigate the carriage of C. difficile in hospitalized horses and the possible influence of some risk factors in colonization. During a seven-month period, faecal samples and data relating the clinical history of horses admitted to a veterinary...
Guss B, Flock M, Frykberg L, Waller AS, Robinson C, Smith KC, Flock JI.Streptococcus equi subspecies equi (S. equi) is a clonal, equine host-adapted pathogen of global importance that causes a suppurative lymphodendopathy of the head and neck, more commonly known as Strangles. The disease is highly prevalent, can be severe and is highly contagious. Antibiotic treatment is usually ineffective. Live attenuated vaccine strains of S. equi have shown adverse reactions and they suffer from a short duration of immunity. Thus, a safe and effective vaccine against S. equi is highly desirable. The bacterium shows only limited genetic diversity and an effective vaccine coul...
Tzipori S, Hayes J, Sims L, Withers M.Streptococcus durans was isolated from a foal with profuse watery diarrhea and caused a similar syndrome when inoculated into foals via the orogastric route. The most consistent and striking histological feature was the extensive colonization of the mucosal surface of the small intestine by S. durans. Associated mucosal changes were mild to modeate, and brush border lactase and alkaline phosphatase production were depressed. S. durans also induced acute diarrhea in young gnotobiotic piglets. Mucosal changes were mild and, as with foals, the mucosal surface of the small intestine was colonized ...
Takai S, Ohkura H, Watanabe Y, Tsubaki S.Quantitative aspects of fecal Rhodococcus (Corynebacterium) equi in newborn foals for 12 weeks after birth were investigated on two horse breeding farms. R. equi was found in the feces of foals during week 1 of life. The greatest numbers of R. equi were present in the feces of foals during the first 8 weeks of their lives, which coincides with the age when foals are most liable to be exposed to R. equi.
Jones SL, Maggi R, Shuler J, Alward A, Breitschwerdt EB.Bartonella spp. are emerging zoonotic agents that have been found in a wide variety of domestic animals and wildlife and cause a number of clinical syndromes. Bartonella sp. infection has been identified in a growing number of animal species, including cats, rodents, porpoises, and canids, but has not been reported in horses. Objective: To document the presence of Bartonella sp. in the blood of horses. Methods: One horse with chronic arthropathy and 1 horse with presumptive vasculitis. Methods: Blood samples were tested for the presence of Bartonella sp. by a combination of multiplex real-time...
Olofsson TC, Butler É, Lindholm C, Nilson B, Michanek P, Vásquez A.In the global perspective of antibiotic resistance, it is urgent to find potent topical antibiotics for the use in human and animal infection. Healing of equine wounds, particularly in the limbs, is difficult due to hydrostatic factors and exposure to environmental contaminants, which can lead to heavy bio-burden/biofilm formation and sometimes to infection. Therefore, antibiotics are often prescribed. Recent studies have shown that honeybee-specific lactic acid bacteria (LAB), involved in honey production, and inhibit human wound pathogens. The aim of this pilot study was to investigate the e...
Nakajima H, Ushimi C.Antigenicity of purified equine infectious anemia (EIA) virus was examined by immunodiffusion against sera obtained from horses experimentally infected with EIA virus. The purified virus reacted with the infected horse serum, and virus-specific precipitating antibody was demonstrated. Furthermore, it was found that purified EIA virus reacted against the serum of horses infected with all strains of EIA virus which were antigenically different from one another. From the result, group-specific components of the virus rather than strain-specific ones were considered to be involved in the reaction....
Giudice E, Giannetto C, Furco V, Alongi A, Torina A.This study was undertaken to determine the prevalence of Anaplasma phagocytophilum infection in Equidae and investigate the possibility of exposure to the organism in Sicily (Southern Italy). During the study blood samples were collected in horses and donkeys housed in five of the nine provinces of Sicilian Island. Of 133 horses and 100 donkeys tested, respectively 9.0% and 6.0% were seroactive (IFAT) with A. phagocytophilum antigen. In only 4.7% of the horses, specific A. phagocytophilum DNA was recorded; in donkey, Anaplasma DNA was not found. Our results indicate a low prevalence of A. phag...
Lee SA, Willeke K, Mainelis G, Adhikari A, Wang H, Reponen T, Grinshpun SA.Bioaerosol sampling is necessary to monitor and control human exposure to harmful airborne microorganisms. An important parameter affecting the collection of airborne microorganisms is the electrical charge on the microorganisms. Using a new design of an electrostatic precipitator (ESP) for bioaerosol sampling, the polarity and relative strength of the electrical charges on airborne microorganisms were determined in several laboratory and field environments by measuring the overall physical collection efficiency and the biological collection efficiency at specific precipitation voltages and po...
Wilkie BN.Effective resistance to respiratory tract infection depends principally on specific immunity on mucosal surfaces of the upper or lower respiratory tract. Respiratory tract immune response comprises antibody and cell-mediated systems and may be induced most readily by surface presentation of replicating agents but can result from parenteral or local presentation of highly immunogenic antigens. Upper and lower respiratory tract systems differ in immunologic competence, with the lungs having a greater inventory of protective mechanisms than the trachea or nose. Several effective vaccines have bee...
Gao Y, Zhang Y, Yang X, Qiu JH, Duan H, Xu WW, Chang QC, Wang CR.Equine strongyles, the significant nematode pathogens of horses, are characterized by high quantities and species abundance, but classification of this group of parasitic nematodes is debated. Mitochondrial (mt) genome DNA data are often used to address classification controversies. Thus, the objectives of this study were to determine the complete mt genomes of three Cyathostominae nematode species (, and ) of horses and reconstruct the phylogenetic relationship of Strongylidae with other nematodes in Strongyloidea to test the hypothesis that spp. belong to Cyathostominae using the mt genomes...
Hampson ECGM, Gibson JS, Barot M, Shapter FM, Greer RM.To identify bacteria and fungi found on the conjunctival surface of normal horse eyes; to investigate potential risk factors for these microflora; and to determine their susceptibility to common topical ophthalmic antimicrobials. Methods: A total of 95 client-owned horses were studied. Methods: Horses within sub-tropical Australia (South-East Queensland) were sampled once between April 2012 and March 2013. A conjunctival swab was taken from each eye and cultured for aerobic bacteria and fungi. Organisms were identified by colony morphology and phenotype. Antimicrobial disk diffusion susceptibi...
Gharsa H, Slama KB, Gómez-Sanz E, Gómez P, Klibi N, Zarazaga M, Boudabous A, Torres C.Staphylococcus intermedius group (SIG) bacteria can colonise the nares of some animals but are also emerging pathogens in humans and animals. Objective: To analyse SIG nasal carriage in healthy donkeys destined for food consumption in Tunisia and to characterise recovered isolates. Methods: Nasal swabs from 100 healthy donkeys were tested for SIG recovery, and isolates were identified by biochemical and molecular methods. Antimicrobial susceptibility of isolates was tested and detection of antimicrobial resistance and virulence genes was performed. Isolates were typed at the clonal level by mu...
Ackermann K, Kenngott R, Settles M, Gerhards H, Maierl J, Wollanke B.Equine recurrent uveitis (ERU) causes painful inflammatory attacks and oftentimes blindness in the affected eyes. The disease is considered a late sequela of systemic leptospirosis. The most effective therapy is the surgical removal of the vitreous (vitrectomy), which is not only therapeutic, but provides vitreous material that can be assessed diagnostically. For example, the lipL32 gene, culturable Leptospira spp., and anti-Leptospira antibodies have all been detected in vitreous samples obtained from eyes with chronic ERU. Despite this clear evidence of leptospiral involvement, the systemic ...
Coxiella burnetii is the causative agent of Q fever. In order to explore the occurrence of C. burnetii in ticks, samples were collected from horses, dogs and humans living in a Cuban occidental community. The species most commonly recovered were Amblyomma mixtum (67%), Rhipicephalus sanguineus s.l. (27%) and Dermacentor nitens (6%). Specific IS1111 PCR and amplicon sequencing allowed the identification of C. burnetii DNA in A. mixtum collected from a domestic horse. These findings, for first time in Cuba, indicate the need for an in-depth assessment of the C. burnetii occurrence in hosts and h...
Yasuda R, Kawano J, Onda H, Takagi M, Shimizu A, Anzai T.To determine patterns of methicillin-resistant staphylococci isolated from apparently healthy horses. Methods: 44 horses from 8 riding clubs in Japan. Methods: Methicill in-resistant staphylococci were isolated from the skin or nares, using a selective medium containing a beta-(symboric) lactam antibiotic, ceftizoxime. Clonality of isolates was determined by use of pulsed-field gel electrophoresis. Detection of mecA, mecl, and mecR1 genes was accomplished by use of polymerase chain reactions. Results: Of the 44 horses, 13 (29.5%) yielded 15 isolates of methicillin-resistant staphylococci. The ...
