Microbiology and horses explores the interactions between microorganisms and equine hosts, focusing on the role of bacteria, viruses, fungi, and other microbes in horse health and disease. This field examines the microbial flora present in various equine environments, including the gastrointestinal tract, skin, and respiratory system, and investigates how these microorganisms influence equine physiology and pathology. Research in this area includes studies on microbial infections that affect horses, the development of antimicrobial resistance, and the impact of probiotics and prebiotics on equine health. This page compiles peer-reviewed research studies and scholarly articles that investigate the diversity, dynamics, and implications of microbial communities in horses, as well as the strategies for managing microbial-related diseases.
Boyle AG, Boston RC, O'Shea K, Young S, Rankin SC.Streptococcus equi is the etiologic agent of a highly infectious upper respiratory disease of horses known as strangles. Bacterial culture methods and polymerase chain reaction (PCR) of nasopharyngeal washes and guttural pouch lavages are used routinely to test clinical and carrier animals for the presence of S. equi but no definitive or gold standard test method has been shown to be optimal. We hypothesized that (i) a flocked swab submerged in ten-fold serial dilution suspensions of S. equi prepared in 0.9% NaCl would detect more colony forming units (CFU) than a rayon swab when used to inocu...
Johns I, Verheyen K, Good L, Rycroft A.The objective of this study was to examine the emergence and persistence of antimicrobial resistant faecal Escherichia coli in horses treated with antimicrobial drugs in a hospital and community setting. Faecal samples were collected from hospitalised (n=56) and non-hospitalised (n=14) horses treated with antimicrobials, and 10 non-treated hospitalised controls. Samples were obtained pre-treatment and 5 days later in all horses, and 2 weeks and 2 months after treatment in treated horses. Susceptibility to 15 antimicrobials was tested via disc diffusion on up to 3 E. coli isolates per sample. P...
Schoster A, Staempfli HR, Arroyo LG, Reid-Smith RJ, Janecko N, Shewen PE, Weese JS.Point prevalence studies have reported carriage rates of enteric pathogens in healthy horses, but longitudinal data are lacking. Commensal E. coli is an indicator organism to evaluate antimicrobial resistance of enteric bacteria, yet there are limited data for horses. The objectives of this study were to investigate and molecularly characterize isolates of Clostridium difficile, Clostridium perfringens and Salmonella, collected sequentially over a one year period, and to determine the antibiotic susceptibility profile for E. coli. Fecal samples were collected monthly from 25 adult horses for o...
Botha M, Botes M, Loos B, Smith C, Dicks LM.Lactobacillus equigenerosi strain Le1, a natural inhabitant of the equine gastrointestinal tract, survived pH 3.0 and incubation in the presence of 1.5% (wt/vol) bile salts for at least 2 h. Strain Le1 showed 8% cell surface hydrophobicity, 60% auto-aggregation, and 47% coaggregation with Clostridium difficile C6. Only 1% of the cells adhered to viable buccal epithelial cells and invaded the cells within 20 min after contact. Preincubation of strain Le1 in a buffer containing pronase prevented adhesion to viable epithelial cells. Preincubation in a pepsin buffer delayed invasion from 20 min to...
Wulijideligen , Asahina T, Hara K, Arakawa K, Nakano H, Miyamoto T.The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral-pH cell-free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clost...
Erol E, Locke SJ, Donahoe JK, Mackin MA, Carter CN.The goal of this retrospective study was to have a comprehensive picture of the β-hemolytic streptococci of horses including tissue/organ distributions and susceptibility patterns against specific antimicrobials between January 1, 2000 and December 31, 2010. A total of 2,497 β-hemolytic streptococci were isolated from 2,391 cases, of which Streptococcus equi subsp. zooepidemicus was the most frequent isolate (72.0%). Other species isolated were Streptococcus dysgalactia subsp. equisimilis (21.3%), Streptococcus equi subsp. equi (5.8%), and unidentified β-hemolytic streptococci (0.9%). As ex...
Knottenbelt DC.A logical and thorough clinical investigation should provide the best basis for the diagnosis of skin diseases. Where no diagnosis can be reached despite a full range of investigations, the clinician can justifiably attempt symptomatic treatment, but it is always better to focus treatment on a specific condition based on properly accumulated and tested clinical evidence. Unfortunately, in equine dermatology there are few text descriptions of the majority of the conditions encountered in practice. While a few diseases are well recognized, there is still little consensus on the best treatments f...
Onishi JC, Park JW, Häggblom MM, Fennell MJ, Fugaro MN.A common sequella of chronic laminitis in horses is repeated abscesses with variable lameness and drainage. It is unclear whether the exudate represents the debridement phase of a non-septic inflammatory process involving clearance of laminar tissue damaged during the acute episode of laminitis, or a response to a microbial infection developed by ascent of microbes from the environment to the tissue via the white line. The objective of this study was to evaluate the possibility that an undiagnosed microbial infection in laminar tissue is present in laminar tissue collected from chronically lam...
Chiers K, Deschaght P, De Baere T, Dabrowski S, Kotlowski R, De Clercq D, Ducatelle R, Vaneechoutte M.Routine cultivation methods are able to distinguish between isolates of the Mycobacterium avium and the Mycobacterium tuberculosis complex. However, molecular tools are needed to further identify the several subspecies in the M. avium complex, especially for the subspecies avium and silvaticum. A rapid technique using HhaI restriction digestion of a 349 bp amplification product of the 85B antigen (α-antigen) gene was used for the identification of M. avium subsp. silvaticum in a three-year-old gelding presenting with caseous, necrotizing, granulomatous lesions. The result was confirmed by seq...
Kulikov E, Kropinski AM, Golomidova A, Lingohr E, Govorun V, Serebryakova M, Prokhorov N, Letarova M, Manykin A, Strotskaya A, Letarov A.Lytic coliphage vB_EcoP_G7C and several other highly related isolates were obtained repeatedly from the samples of horse feces held in the same stable thus representing a component of the normal indigenous intestinal communities in this population of animals. The genome of G7C consists of 71,759 bp with terminal repeats of about 1160 bp, yielding approximately 73 kbp packed DNA size. Seventy-eight potential open reading frames, most of them unique to N4-like viruses, were identified and annotated. The overall layout of functional gene groups was close to that of the original N4 phage, with som...
Holý O, Matousková I, Holý V, Koukalová D, Chmelar D.Cronobacter spp. belongs to the family Enterobacteriaceae. It is a motile (peritricha) Gram-negative non-spore forming bacterium. At present, Enterobacter sakazakii is reported as a Cronobacter spp. species with 16 biogroups. It is a ubiquitous organism whose isolation used to be associated with a contaminated powdered infant formula and feed for neonates and infants. Information about the Cronobacter spp. species incidence in the environment, its potential dissemination and its vectors, is very limited. The authors have documented incidence of Cronobacter spp. in the nostril mucous membrane o...
Perkins GA, den Bakker HC, Burton AJ, Erb HN, McDonough SP, McDonough PL, Parker J, Rosenthal RL, Wiedmann M, Dowd SE, Simpson KW.Little is known about the gastric mucosal microbiota in healthy horses, and its role in gastric disease has not been critically examined. The present study used a combination of 16S rRNA bacterial tag-encoded pyrosequencing (bTEFAP) and fluorescence in situ hybridization (FISH) to characterize the composition and spatial distribution of selected gastric mucosal microbiota of healthy horses. Biopsy specimens of the squamous, glandular, antral, and any ulcerated mucosa were obtained from 6 healthy horses by gastroscopy and from 3 horses immediately postmortem. Pyrosequencing was performed on bio...
Vosmer J, Liesegang A, Wanner M, Zeyner A, Suter D, Hoelzle L, Wichert B.The aim of the present study was to compare carbohydrate degradation of forages which store carbohydrates either predominantly as fructan or starch, in horses' hindgut. The effects of an abrupt change from hay-based feeding to green fodder-based feeding on the caecal flora were tested with the in vitro hindgut simulation technique 'Caesitec'. Six trials with different forages (English ryegrass, tall fescue, grass mixture-horses, grass mixture-cows, lucerne, white clover) were conducted. During a 4-day stabilisation period, samples were taken once a day before loading the fermenters with hay. A...
Schlusselhuber M, Jung S, Bruhn O, Goux D, Leippe M, Leclercq R, Laugier C, Grötzinger J, Cauchard J.Rhodococcus equi, the causal agent of rhodococcosis, is a severe pathogen of foals but also of immunodeficient humans, causing bronchopneumonia. The pathogen is often found together with Klebsiella pneumoniae or Streptococcus zooepidemicus in foals. Of great concern is the fact that some R. equi strains are already resistant to commonly used antibiotics. In the present study, we evaluated the in vitro potential of two equine antimicrobial peptides (AMPs), eCATH1 and DEFA1, as new drugs against R. equi and its associated pathogens. The peptides led to growth inhibition and death of R. equi and ...
Hébert L, Moumen B, Pons N, Duquesne F, Breuil MF, Goux D, Batto JM, Laugier C, Renault P, Petry S.The Taylorella genus comprises two species: Taylorella equigenitalis, which causes contagious equine metritis, and Taylorella asinigenitalis, a closely-related species mainly found in donkeys. We herein report on the first genome sequence of T. asinigenitalis, analyzing and comparing it with the recently-sequenced T. equigenitalis genome. The T. asinigenitalis genome contains a single circular chromosome of 1,638,559 bp with a 38.3% GC content and 1,534 coding sequences (CDS). While 212 CDSs were T. asinigenitalis-specific, 1,322 had orthologs in T. equigenitalis. Two hundred and thirty-four T...
Leon A, Richard E, Fortier C, Laugier C, Fortier G, Pronost S.Abortion, stillbirth and neonatal death are major causes of equine mortality and cause severe economic loss to the equine industry. The present study was based on a complete necropsy protocol associated with classical microbiological examinations and molecular biology on 407 cases of abortion, stillbirths and neonate death. Based on this retrospective survey, "less common" abortive infectious agents were characterised by molecular tools in nine independent cases of abortion or neonate mortality. Among others, Chlamydophila abortus (1 case), Coxiella burnetii (6 cases) and Neospora caninum (3 c...
Janczyk P, Weigner J, Luebke-Becker A, Richardson KC, Plendl J.Most embalming of cadavers for anatomical dissection in veterinary medicine has used 6-10% formaldehyde resulting in discoloured and rigid specimens. This project produced teaching specimens of sheep, horse and calf cadavers having their musculoskeletal and visceral structures with a natural appearance using a fixation solution with lowered concentrations of formaldehyde (2% and 3%) together with ethanol and polyethylene glycols. Fixation parameters (palpable consistency, flexibility, colour, tissue hydration and odour) were assessed qualitatively by twice weekly dissections over two months fo...
Shepherd ML, Swecker WS, Jensen RV, Ponder MA.The diversity of the equine fecal bacterial community was evaluated using pyrosequencing of 16S rRNA gene amplicons. Fecal samples were obtained from horses fed cool-season grass hay. Fecal bacteria were characterized by amplifying the V4 region of bacterial 16S rRNA gene. Of 5898 mean unique sequences, a mean of 1510 operational taxonomic units were identified in the four fecal samples. Equine fecal bacterial richness was higher than that reported in humans, but lower than that reported in either cattle feces or soil. Bacterial classified sequences were assigned to 16 phyla, of which 10 were ...
Griffeth GC, Callori N, Rankin SC, Boston RC, Morris DO.Meticillin-resistant Staphylococcus aureus (MRSA) causes serious skin and soft-tissue infections of humans and animals. Multiple strains of MRSA have been characterized, and one in particular, designated as strain USA 500, causes infections predominantly of horses and the people who work with them. The purpose of this study was to optimize an assay which could subsequently be used to compare the relative avidity of different S. aureus strains for equine corneocytes. Corneocytes were collected from the perineal skin of 10 healthy horses onto adhesive discs. The discs were then incubated at 37°...
Bourgeois MA, Denslow ND, Seino KS, Barber DS, Long MT.Gene expression associated with West Nile virus (WNV) infection was profiled in the central nervous system of horses. Pyrosequencing and library annotation was performed on pooled RNA from the CNS and lymphoid tissues on horses experimentally infected with WNV (vaccinated and naïve) and non-exposed controls. These sequences were used to create a custom microarray enriched for neurological and immunological sequences to quantitate gene expression in the thalamus and cerebrum of three experimentally infected groups of horses (naïve/WNV exposed, vaccinated/WNV exposed, and normal).From the sequ...
Wong SS, Ngan AH, Riggs CM, Teng JL, Choi GK, Poon RW, Hui JJ, Low FJ, Luk A, Yuen KY.The newly described brittle tail syndrome causes weakening and breakage of the tail hair of horses. Extensive mycological and molecular studies showed that a novel fungus Equicapillimyces hongkongensis gen. nov., sp. nov. is the most likely cause of this syndrome. It is a septate branching hyaline mould which grows optimally at 30°C, requires nicotinic acid but is inhibited by cycloheximide, and specifically infects horse hair. Hyphae fill the core of infected hair shafts with short-necked structures resembling ascomata containing banana-shaped septate ascospore-like structures perforating th...
de Sousa ME, Araújo MA, Mota RA, Porto WJ, Souza AK, Dos Santos JL, da Silva PP.Normal fungal conjunctiva microbiota of horses remains stable in healthy animals, free from ocular and/or systemic diseases which may, eventually, cause ocular alterations. The knowledge of the fungal microbiota is of great importance due to the reduced number of studies reported in the literature and also to the large occurrence of ocular alterations, mainly keratomycosis, in these animals. The aim of this study was to isolate and to identify the fungi present in the ocular conjunctiva of healthy horses belonging to the Military Police Cavalry of Alagoas. Samples from both conjunctival sacks ...
Maddox TW, Clegg PD, Diggle PJ, Wedley AL, Dawson S, Pinchbeck GL, Williams NJ.The increasing prevalence of antimicrobial-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and antimicrobial-resistant Escherichia coli represents a significant problem. However, the carriage of such bacteria by horses in the UK has not been well characterised. Objective: To estimate the prevalence of nasal carriage of MRSA and faecal carriage of antimicrobial-resistant E. coli amongst horses in the general equine community of the mainland UK. Methods: A cross-sectional study of horses recruited by 65 randomly selected equine veterinary practices was conducted, wi...
Simmons DR, Letcher PM, Powell MJ, Longcore JE.The order Lobulomycetales contains chytrids from soil, freshwater and marine habitats; environmental DNA sampling has indicated that representatives of this order might be found in deep ocean localities. We describe Alogomyces tanneri as the first lobulomycetalean chytrid isolated from horse manure; A. tanneri is also the first species in the order to possess a rumposome in its zoospore. This species widens the range of habitats, ultrastructural variation and thallus morphology for Lobulomycetales.
Sutton DG, Preston T, Love S.Validation of a reliable, noninvasive clinical test for quantification of equine orocaecal transit time (OCTT) is required. This would facilitate an evidence-based approach to investigation and treatment of equine small intestinal disorders. Objective: 1) Comparison of the lactose (13) C-ureide breath test (LUBT) with the hydrogen breath test (H(2) BT) for OCTT measurement. 2) Identification of the characteristics of gastrointestinal microbial glycosylureide hydrolase activity in vitro. 3) Production of an optimised protocol for the LUBT for in vivo measurement of equine OCTT. Objective: Signi...
Kennedy MW.Horses and other equids are unusual in producing protein-rich sweat for thermoregulation, a major component of which is latherin, a highly surface-active, non-glycosylated protein that is a member of the PLUNC (palate, lung and nasal epithelium clone) family. Latherin produces a significant reduction in water surface tension at low concentrations (≤1 mg/ml), and probably acts as a wetting agent to facilitate evaporative cooling through a thick, waterproofed pelt. Latherin binds temporarily to hydrophobic surfaces, and so may also have a disruptive effect on microbial biofilms. It may conseq...
Cui Z, Shi J, Li Y.The spent wheat straw from horse stall bedding has lower cellulose and hemicellulose contents, but higher volatile fatty acid content than raw wheat straw. Biogas production from solid-state anaerobic digestion (SS-AD) of spent wheat straw and raw wheat straw was compared in this study. The SS-AD tests were conducted at 22% total solids (TS) content using inoculum from a liquid AD system at three feedstock-to-inoculum (F/I) ratios of 2.0, 4.0, and 6.0. Daily methane yields of spent wheat straw peaked 8 and 3 days earlier than those of raw wheat straw at F/I ratios of 2.0 and 4.0, respectively....
Waller AS, Paillot R, Timoney JF.Strangles caused by the host adapted Lancefield group C Streptococcus equi subspecies equi (S. equi) is a frequently diagnosed infectious disease of horses worldwide. Critical to the global success of S. equi is its ability to establish persistent infections within the guttural pouches of recovered apparently healthy horses that can result in transmission to in-contact animals. Recent research has identified key events in the S. equi genome, which occurred during its evolution from an ancestral strain of S. equi subspecies zooepidemicus, that may enhance its ability to evade host innate immune...
Damborg P, Marskar P, Baptiste KE, Guardabassi L.The objective of this longitudinal study was to investigate the occurrence and genetic background of faecal Escherichia coli resistant to cefotaxime (CTX) in horses receiving broad-spectrum antimicrobial prophylaxis after admission to a veterinary teaching hospital. The ten horses enrolled in the study were treated with cefquinome either alone (n=4) or in combination with metronidazole (n=3) or other antimicrobial agents (n=3). CTX-resistant coliforms in faeces collected before, during and after treatment were quantified on selective MacConkey agar supplemented with CTX, and a colony isolated ...
Di Pietro R, Arroyo LG, Leclere M, Costa M.Bacterial imbalances are observed in intestinal diseases and fecal microbiota transplantation (FMT) has been used to restore the intestinal microbiota of horses. However, there is evidence that the current methods proposed for FMT in horses have limited efficacy. The objective of this study was to concentrate the bacteria present in the donor stool by centrifugation, and to test the effect in horses with antibiotic-induced dysbiosis. One healthy 11-year-old horse was selected as a fecal donor and 9 horses were given trimethoprim sulfadiazine (TMS) for 5 days to induce dysbiosis. Horses receive...
Pollaris E, Staszyk C, Proost K, Boone MN, Josipovic I, Pardon B, Vlaminck L.Fissures on the occlusal surface of equine cheek teeth are commonly encountered during oral examination. Generally, their presence is considered abnormal but their aetiopathogenesis and clinical impact on pulp disease is still undetermined. The aims of this research were to study the extent of occlusal cheek teeth fissures using high-resolution X-ray computed tomography (μCT) imaging and their histological characteristics. Twenty-seven teeth (of 15 horses) were scanned using μCT imaging to analyse fissure extent. Histological examination of a subset of teeth (n=7) was performed. Forty-three ...
Berreta A, Burbick CR, Alexander T, Kogan C, Kopper JJ.Probiotics are defined as live microorganisms that confer a health benefit to the host when administered in adequate amounts, therefore the presence of viable microorganisms is essential. Previous studies reported inconsistencies when comparing contents of probiotics marketed for use in animals with label claims. However, to the author's knowledge the variability of the same product between different lots has yet to be evaluated. The objective of this observational study was to evaluate the content and inter-lot variability of commercial equine probiotic products using culture dependent and in...
Christley RM, Hodgson DR, Rose RJ, Reid SW, Hodgson JL.Cytological and bacteriological results from tracheal fluid samples obtained endoscopically using a telescoping, plugged catheter (TPC) were compared with results from samples collected by percutaneous transtracheal aspiration (PTA). The TPC technique and PTA were performed in random order on 9 healthy Standardbred geldings. Three weeks later the procedures were performed on the same horses in the reverse order. The presence of oropharyngeal contamination was determined by quantitative bacteriology and quantification of squamous epithelial cells (SEC)/ml sample. The relative numbers of macroph...
Vinogradov E, MacLean LL, Brooks BW, Lutze-Wallace C, Perry MB.Taylorella asinigenitalis sp. nov is a nonpathogenic gram-negative bacterium recently isolated from the genital tract of male donkeys. The bacterium is phenotypically indistinguishable from Taylorella equigenitalis, a pathogen that is the cause of contagious equine metritis, a highly communicable venereal disease of horses. The structural analysis of the lipopolysaccharide produced by T. asinigenitalis sp. nov (ATCC 700933) demonstrated that its O-polysaccharide (O-PS) component is a linear unbranched polymer of repeating disaccharide units composed of 1,3-linked pyranosyl residues of 2,4-diac...
Fraczkowska K, Zak-Bochenek A, Siwinska N, Rypula K, Ploneczka-Janeczko K.From a clinical point of view, knowledge of the commensal microbial flora of the conjunctival sac in healthy individuals proves to be of great importance. The aim of this study was to assess the presence and the composition of normal ocular microflora of healthy donkeys. Fourteen clinically healthy donkeys () participated in the study. After prior ophthalmological examination, which showed no abnormalities, a conjunctival swab was taken from each donkey from the right and left eye. Species-specific identification was based on a morphological assessment of bacterial colonies stained with the Gr...
Corrente M, D'Abramo M, Latronico F, Greco MF, Bellacicco AL, Greco G, Martella V, Buonavoglia D.A methicillin-resistant (MR) Staphylococcus epidermidis strain was isolated from a saddle horse affected by osteolysis. MR coagulase-negative staphylococci (MRCNS) were isolated from 11 of 14 (78.8%) horses housed in the same riding club. By typing of the SCCmec region, almost the strains displayed a non typeable (NT) pattern and possessed the ccr type 2. Altogether, the high prevalence of MRCNS and the detection of NT SCCmec types support the hypothesis that horses may represent a reservoir of MRCNS for humans and that equine MRCNS may act as potential source of resistance genes for other sta...
Giguère S, Jordan LM, Glass K, Cohen ND.Isolation of multiple bacterial species is common in foals with Rhodococcus equi pneumonia. Objective: There is no association between isolation of other microorganisms and outcome. Methods: 155 foals with pneumonia caused by R. equi. Methods: Case records of foals diagnosed with R. equi pneumonia based on culture of the respiratory tract were reviewed at 2 referral hospitals (University of Florida [UF] and Texas A&M University [TAMU]). Results: R. equi was cultured from a tracheobronchial aspirate (TBA) in 115 foals and from lung tissue in 38 foals. Survival was significantly higher at UF...
Vera L, Boyen F, de Visscher A, Vandenbroucke V, Vanantwerpen G, Govaere J.The use of commercial chromogenic agar plates for the rapid, easy and correct identification of equine endometritis-causing bacteria has been proposed. Preliminary tests in our lab revealed undescribed limitations. Therefore, we tested the ability of the Brilliance UTI agar, a commercially available chromogenic agar, to accurately identify bacteria causing equine endometritis. Objective: To 1) investigate whether bacteria present in the equine uterus are able to grow on this chromogenic agar plate, 2) determine whether these bacteria belong to the genera for which these agar plates were origin...
Goudah A, Abo El-Sooud K, Shim JH, Shin HC, Abd El-Aty AM.The target of the present study was to investigate the plasma disposition kinetics of levofloxacin in stallions (n = 6) following a single intravenous (i.v.) bolus or intramuscular (i.m.) injection at a dose rate of 4 mg/kg bwt, using a two-phase crossover design with 15 days as an interval period. Plasma samples were collected at appropriate times during a 48-h administration interval, and were analyzed using a microbiological assay method. The plasma levofloxacin disposition was best fitted to a two-compartment open model after i.v. dosing. The half-lives of distribution and elimination were...
Urubschurov V, Stroebel C, Günther E, Romanowski K, Büsing K, Zeyner A.Effects of probiotics on the intestinal microbiota of foals are yet insufficiently studied. The aim of this study was to investigate whether supplementation of Lactobacillus rhamnosus (DSM 7133) and Enterococcus faecium (DSM 7134) influences the bacterial composition of the faecal microbiota of foals. A total of 34 newborn foals were randomly assigned to the placebo group (PG, n = 16) and the treatment group (TG, n = 18). From day 1 to day 14 of life, foals orally received 3 ml of either a probiotic preparation (1.05 × 10 CFU E. faecium and 4.50 × 10 CFU L. rhamnosus) or placebo (...
Farnet AM, Qasemian L, Peter-Valence F, Ruaudel F, Savoie JM, Ferré E.The potential of Agaricus subrufescens strains to colonize and transform horse manure and wheat-straw-based mushroom compost under the physico-chemical conditions typically used for Agaricus bisporus was assessed. Lignocellulolytic activities, H2O2 production and substrate transformation (assessed via CP/MAS NMR of (13)C) for certain A. subrufescens strains were similar or even greater than those obtained for an A. bisporus strain used as control. Moreover, the functional diversity of the microbial communities of the substrate was not altered by the growth of A. subrufescens after 2weeks. Thes...
Ward PL, Wohlt JE, Katz SE.Two experiments were conducted comparing pelleted recycled newspaper (PN) to wheat straw (S) and kiln-dried pine wood shavings (WS) as an animal bedding material. Adult horses housed 20 to 21 h/d in boxstalls served as the animal model for comparisons. In Exp. 1 eight boxstalls, each housing one horse, were each bedded with two types of PN (0.32 and 0.64 x 2.54 cm), S, and WS over four 5-d periods (replicated 4 x 4 Latin square). Initial amounts of bedding materials surpassed most commercial conditions, but stalls were cleaned daily of feces only and additional clean bedding was added as neede...
Adler DM, Cornett C, Damborg P, Verwilghen DR.Local anaesthetics (LAs) are frequently used for diagnostic procedures in equine veterinary practice. The objective of this study was to investigate the physico-chemical stability and bacterial contamination of bupivacaine, lidocaine and mepivacaine used for lameness examinations in horses. The LAs were stored in 12 different groups at different temperatures (-18 °C to 70 °C), light intensities and in common veterinary field conditions for up to 16 months. The pH, presence of bacterial contamination and concentrations of LAs and methylparaben (a preservative present in lidocaine) were de...
Lakritz J, Wilson WD, Mihalyi JE.To determine pharmacokinetics and bioavailability of erythromycin base after intragastric administration and erythromycin lactobionate after IV administration to healthy foals and to compare a microbiologic assay with a high-performance liquid chromatography (HPLC) method to determine plasma concentrations of erythromycin A. Methods: 6 healthy foals that were 2 to 4 months old. Methods: Foals were given single doses of erythromycin (10 mg/kg of body weight, IV, and 25 mg/kg, intragastrically) in a crossover study. Venous blood samples were obtained at specific times after drug administration, ...
Hu D, Wang C, Ente M, Zhang K, Zhang D, Li X, Li K, Chu H.Intestinal microbiota play an important role in the survival of the host. However, no study to date has elucidated the adjustment of intestinal microbiota of the host during rewilding. Thus, this study aims to describe the intestinal bacterial community of reintroduced Przewalski’s horse (RPH) after being released into their original habitat for approximately 20 years in comparison with that of captive Przewalski’s horse (CPH), sympatric domestic horse (DH) and Mongolian wild ass (MWA) by sequencing the 16S rRNA gene. The results showed that the prevalent bacterial communities were differe...
Vigolo V, Gautier C, Falomo ME, Aurich C.The use of microfluidic technology is increasing in artificial reproduction technologies: With a small amount of semen, it allows for the selection of sperm with the best characteristics of kinetics, morphology and chromatin integrity. The ZyMot Multi (850 μl) is the most popular device of ZyMot Fertility Inc. To date, it was proven to be a valid instrument for sperm selection for in vitro fertilization and intracytoplasmic sperm injection in men. The aim of this study was to test the efficacy of the ZyMot Multi (850 μl) for stallion semen. Frozen-thawed semen from 15 stallions that were...
Peyrou M, Higgins R, Lavoie JP.Evolution of bacterial resistance to certain antibacterial agents in horses in a veterinary hospital. A total of 255 antibiograms, conducted according to the Kirby-Bauer method from bacterial isolates collected from horses at the Hôpital Vétérinaire d'Enseignement at the Université de Montréal between 1996 and 1998 were compared with the results obtained about 10 years ago with corresponding bacterial species. A significant increase in the percentage of strains resistant to trimethoprim-sulfamethoxazole (TMP-SXT), penicilline, tetracycline, and to gentamicin was observed. The percentages ...
Blancquaert AM, Colgan SP, Bruyninckx WJ.Although equine neutrophils did not respond towards formylated methionyl peptides, Streptococcus faecalis culture supernatant caused an in vitro stimulation of equine neutrophil motility when measured by an under-agarose assay. The migration of neutrophils towards the culture supernatant increased sigmoidally with the logarithmic concentration of the culture supernatant in the chemoattractant wells. The streptococcal culture supernatant was chemokinetic because it stimulated the random motility of the phagocytes. Because granulocytes migrated further towards the supernatant than could be expla...
Zhang Y, Long R, Warzecha CM, Coverdale JA, Latham EA, Hume ME, Callaway TR, O'Neil MR, Beier RC, Anderson RC, Nisbet DJ.The nitrotoxins 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) are produced by a wide variety of leguminous plants, including over 150 different species and varieties of Astragalus potentially grazed by livestock. These toxins are known to be detoxified by at least one ruminal bacterium but detoxification by bacteria from other gut habitats is not known. In the present study, mixed populations of bovine ruminal and equine cecal microbes were enriched for NPA-metabolizing bacteria via consecutive 24-72 h culture in a basal minimal rumen fluid-based medium supplemented with 4.2 mM ...
Adam EN, Southwood LL.To determine historical, physical, and microbiologic findings in horses with limb cellulitis and identify factors associated with short- and long-term outcome. Methods: Retrospective case series. Methods: 44 horses with limb cellulitis. Methods: Information obtained from medical records included use, history, affected limb, diagnostic procedures, treatment, and short-term outcome. Long-term follow-up information was obtained by means of a telephone survey. Results: Twenty-four horses had primary cellulitis, and 18 of the 24 (75%) had a hind limb affected. Results of microbiologic culture were ...
Padoan E, Ferraresso S, Pegolo S, Barnini C, Castagnaro M, Bargelloni L.Mild equine asthma (MEA) and severe equine asthma (SEA) are two of the most frequent equine airway inflammatory diseases, but knowledge about their pathogenesis is limited. The goal of this study was to investigate gene expression differences in the respiratory tract of MEA- and SEA-affected horses and their relationship with clinical signs. Methods: Clinical examination and endoscopy were performed in 8 SEA- and 10 MEA-affected horses and 7 healthy controls. Cytological and microbiological analyses of bronchoalveolar lavage (BAL) fluid were performed. Gene expression profiling of BAL fluid wa...
Lindeberg H, Karjalainen H, Koskinen E, Katila T.A study was performed to test a new semen collection device (Equidame phantom) that fractionates the ejaculate by comparing the quality of semen obtained by the Equidame phantom with that obtained by a Missouri artificial vagina. Semen from 4 Finnhorse stallions was collected 4 times per stallion by both methods. Half of the ejaculate was frozen and the other half extended and loaded into 2 Equitainer transport containers (24- and 48-h samples). Motility parameters were determined by a Hamilton-Thorn motility analyzer after cooled storage for 24 and 48 h and again after freezing/thawing. Raw a...
Geraghty TE, Love S, Taylor DJ, Heller J, Mellor DJ, Hughes KJ.The sites of insertion of catheters into the jugular veins of six horses were investigated to determine common isolates and to assess the effectiveness of two disinfection protocols with the hair coat left long, clipped or shaved. Skin commensals (Staphylococcus, Streptococcus and Micrococcus species) and environmental contaminants (Bacillus, Enterobacteriaceae, Aspergillus and Mucor species) were the microorganisms most frequently isolated. Chlorhexidine gluconate and povidone-iodine-based skin disinfection protocols resulted in significant reductions in the number of bacterial isolates from ...
Kuhn M, Guschlbauer M, Feige K, Schluesener M, Bester K, Beyerbach M, Breves G.Equine typholocolitis is a sporadic diarrheal disease causing high mortality rates. One of the risk factors responsible for this is the oral application of the macrolide antibiotic erythromycin. The aim of the present in vitro study was to investigate whether erythromycin in combination with feed restriction provokes changes in microbial hindgut metabolism and could therefore be involved in the pathogenesis of equine typhlocolitis. As application of erythromycin and feed restriction are risk factors for equine typhlocolitis, both factors were chosen to investigate their individual and combined...
Takeda S, Ohta M, Ebina S, Nagayama K.Horse L-ferritin cDNA was cloned from horse liver, and the base sequence was determined. The L-ferritin was expressed using pTZ18U encoding lac promoter, and found to possess an additional 8-amino acid sequence at the N-terminus as compared with commercially obtained horse spleen (natural) ferritin. It was determined that there was Pro at position 94 in both the recombinant and natural L-ferritin, although it was previously reported that Leu was in this position in the natural species. Transmission electron microscopy showed that this recombinant ferritin formed a 24-mer shell.
Agrawal K, Ebel JG, Altier C, Bischoff K.The leaves of Acer rubrum (red maple), especially when wilted in the fall, cause severe oxidative damage to equine erythrocytes, leading to potentially fatal methemoglobinemia and hemolytic anemia. Gallic acid and tannins from A. rubrum leaves have been implicated as the toxic compounds responsible for red maple toxicosis, but the mechanism of action and toxic principle(s) have not been elucidated to date. In order to investigate further how red maple toxicosis occurs, aqueous solutions of gallic acid, tannic acid, and ground dried A. rubrum leaves were incubated with contents of equine ileum,...
Jin Y, Li W, Ba X, Li Y, Wang Y, Zhang H, Li Z, Zhou J.Zoonotic diseases pose a significant threat to public health. Chlamydia, as an intracellular pathogen, can colonize the intestinal tract of humans and animals, changing the gut microbiota. However, only a few studies have evaluated alterations in the gut microbiota of horses infected with Chlamydia. Therefore, this study aimed to investigate gut microbiota and serum biochemical indicators in horses with Chlamydial infection (IG) and healthy horses (HG). Fecal and blood samples were collected from 16 horses (IG: 10; HG: 6) before morning feeding for the determination of gut microbiota and serum...
Szeredi L, Molnár T, Glávits R, Takai S, Makrai L, Dénes B, Del Piero F.Rhodococcus equi was isolated from lung, liver, spleen, and stomach content of two aborted equine fetuses of 7 and 8 months gestation from two different farms. Lesions included diffuse pyogranulomatous pneumonia with numerous Gram-positive coccobacilli within the cytoplasm of macrophages, multinucleated Langhans giant cells and neutrophils, and enhanced extramedullary hematopoiesis with megakaryocytosis within the liver and spleen. Detection of R. equi was made by bacteriology and immunohistochemistry for R. equi and VapA, the virulence factor of R. equi. R. equi and VapA were identified withi...
Wilsher S, Omar H, Ismer A, Allen T, Wernery U, Joseph M, Mawhinney I, Florea L, Thurston L, Duquesne F, Petry S.Three horse mares inadvertently inseminated with semen from a Tayorella asinigenitalis-positive Jack donkey developed severe, purulent endometritis whereas two Jenny donkeys mated naturally to the same Jack donkey did not develop clinical signs of infection. Objective: To isolate and identify the causative agent. Methods: Case report. Methods: Endometrial swabs from the infected mares were cultured on selective and non-selective media under aerobic and microaerophilic conditions. Isolates were subjected to Gram staining, oxidase and catalase tests, the Monotayl Latex Agglutination test and PCR...
