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.
Bonenberger TE, Ihrke PJ, Naydan DK, Affolter VK.Immunostaining with polyclonal anti-Mycobacterium bovis (BCG) was evaluated as a single screening method for the histological identification of micro-organisms in skin biopsy specimens from various veterinary species. Confirmed archival cases infected with Mycobacteria, Nocardia, Actinobacillus, Actinomyces, Streptococcus/Staphylococcus, Dermatophilus, spirochetes, Blastomyces, Coccidioides, Cryptococcus, Histoplasma, dermatophytes, Malassezia, Sporothrix, Leishmania, Pythium, phaeohyphomycetes and Prototheca organisms were selected. A total of 70 skin biopsy specimens from the dog, cat, horse...
Sellon DC, Besser TE, Vivrette SL, McConnico RS.Recently, a technique was described for amplification of Rhodococcus equi-specific chromosomal and vapA DNA from blood and tracheal wash fluids. It was hypothesized that this technique would be more sensitive than standard culture techniques or serology for diagnosis of R. equi pneumonia in foals. Tracheal wash fluid, nasal swabs, whole blood samples, and serum samples from 56 foals with pneumonia were analyzed. Final clinical diagnosis was determined by the attending clinician on the basis of final interpretation of all available information about each foal, including clinical presentation, d...
Takai S, Ogawa K, Fukunaga N, Sasaki Y, Kakuda T, Tsubaki S, Anzai T.R. equi was isolated from soil samples obtained from the environment of seven native Japanese horse breeds (Hokkaido, Kiso, Noma, Misaki, Tokara, Miyako and Yonaguni) and from fecal samples collected from three native horse breeds (Hokkaido, Kiso and Misaki). Virulent R. equi at various levels (ranging from 0.5 to 12.9%) was isolated from the feces or soil environment of Hokkaido, Kiso and Misaki horses. Isolates were investigated both for the presence of 15- to 17-kDa antigens (virulence-associated protein antigens; VapA) by colony blotting, using the monoclonal antibody 10G5, and the gene of...
Marsh AE, Mullins AL, Lakritz J.Parasite-specific incorporation of (3)H-uracil was used to assess the replication of Sarcocystis neurona, a protozoal parasite associated with equine protozoal myeloencephalitis (EPM). Anti-protozoal drugs, pyrimethamine (0.01, 0.1 and 1.0microg/ml PYR), sulfadiazine (5microg/ml; SDZ), sulfamethoxazole (5microg/ml; SMZ), diclazuril (100ng/ml; DCZ), atovaquone (0.04ng/ml; ATQ), tetracycline (5microg/ml; TET) and the herbicide glyphosate (1.5 and 4.5mM; GLY) were studied with varying S. neurona parasite densities (2x10(1)-1.2x10(6)merozoites/well). A microtiter plate format was used to test thes...
Dabareiner RM, White NA, Donaldson LL.To determine whether intraluminal distention and subsequent decompression of the equine jejunum affects intestinal blood flow, hemodynamics, and microvascular permeability. Methods: 5 healthy adu t horses. Methods: Horses were anesthestized and underwent exploratory laparotomy. Two jejunal segments were identified as sham-operated or instrumented segments. After baseline values were obtained, intraluminal distention was created in the experimental segment to induce an ntraluminal pressure of 18 cm H2O. After 120 minutes of distention, the intestine was decompressed for 120 minutes. Mesenteric ...
Ryan MP, McAuliffe O, Ross RP, Hill C.Lacticin 3147 is a broad-spectrum, two-component, lanthionine-containing bacteriocin produced by Lactococcus lactis DPC3147 which has widespread food and biomedical applications as a natural antimicrobial. Other two-component lantibiotics described to date include cytolysin and staphylococcin C55. Interestingly, cytolysin, produced by Enterococcus faecalis, has an associated haemolytic activity. The objective of this study was to compare the biological activity of lacticin 3147 with cytolysin. The lacticin 3147-encoding determinants were heterologously expressed in Ent. faecalis FA2-2, a plasm...
Keller M, Krehon S, Stanek C, Rosengarten R.Specimens of hoof horn from 187 horses were examined for a possible relationship between clinically affected hooves and the occurrence of pathogenic fungi. Specimens were taken from the coronary band and from the stratum externum and medium of the coronary horn and transferred on to Sabouraud dextrose agar, with and without cycloheximide, and incubated at 28 degrees C. Dermatophytes and mould fungi were identified by their macroscopic and microscopic characteristics. The 732 isolates could be assigned to 26 species of moulds, two different species of the dermatophyte Microsporum and three diff...
Sutcliffe IC, Trigg J, Harrington D.Using preparative electrophoresis, a low molecular weight protein has been partially purified from a cell extract of the equine pathogen Streptococcus equi susp. equi. N-terminal sequence analysis and Western blotting revealed the protein to be HPr, a central component of the phosphoenolpyruvate:sugar phosphotransferase system (PTS). Interestingly, the only form of the HPr protein detected in S. equi was one with the amino-terminal methionine removed, a modification that has previously been associated with surface localization of streptococcal HPr proteins.
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 ...
Hamilton A, Harrington D, Sutcliffe IC.Acid phosphatases hydrolyse phosphomonoesters at acidic pH in a variety of physiological contexts. The recently defined class C family of acid phosphatases includes the 32 kDa LppC lipoprotein of Streptococcus equisimilis. To define further the distribution of acid phosphatases in the genus Streptococcus we have examined the equine pathogens Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus. Whole cell assays indicated that these organisms possess two acid phosphatases with activity optima at pH 5.0 and pH 6.0-6.5 and that only the former of these was, like LppC, resis...
Yuki N, Shimazaki T, Kushiro A, Watanabe K, Uchida K, Yuyama T, Morotomi M.Selective adhesion to only certain epithelia is particularly common among the bacterial members of the indigenous microflora of mammals. We have found that the stratified squamous epithelium of the nonsecreting area of horse stomach is colonized by gram-positive rods. The microscopic features of a dense layer of these bacteria on the epithelium were found to be similar to those reported in mice, rats, and swine. Adhering microorganisms were isolated and identified as Lactobacillus salivarius, L. crispatus, L. reuteri, and L. agilis by DNA-DNA hybridization and 16S rRNA gene sequencing techniqu...
Mills ML, Rush BR, St Jean G, Gaughan EM, Mosier D, Gibson E, Freeman L.To determine the serum and synovial fluid concentrations of ceftiofur sodium after intraarticular (IA) and intravenous (IV) administration and to evaluate the morphologic changes after intraarticular ceftiofur sodium administration. Methods: Strip plot design for the ceftiofur sodium serum and synovial fluid concentrations and a split plot design for the cytologic and histopathologic evaluation. Methods: Six healthy adult horses without lameness. Methods: Stage 1: Ceftiofur sodium (2.2 mg/kg) was administered IV. Stage 2: 150 mg (3 mL) of ceftiofur sodium (pHavg 6.57) was administered IA into ...
Lakritz J, Wilson WD, Marsh AE, Mihalyi JE.To determine effects of prior feeding on pharmacokinetics and estimated bioavailability of orally administered microencapsulated erythromycin base (MEB) in healthy foals. Methods: 6 healthy foals, 3 to 5 months old. Methods: Foals were given 2 doses of MEB (25 mg/kg of body weight, PO). One dose was administered after food was withheld overnight, and the other was administered after foals had consumed hay. The study used a crossover design with a 2-week period between doses. Blood was collected via a jugular vein prior to and at specific times after drug administration. Concentrations of eryth...
Sarma PN, Tang YJ, Prindiville TP, Osborne PD, Jang S, Silva J, Cohen SH.In order to determine genetic relatedness of Bacteroides fragilis isolates from different clinical sources, arbitrarily primed polymerase chain reaction (PCR) (AP-PCR) was used to compare 17 strains isolated from patients with inflammatory bowel disease (IBD) and 20 strains isolated from foals with diarrhea. Three reference ATCC strains were also analyzed. Eighteen unique types were identified with a 22-mer arbitrary primer (ERIC-2) among the 20 patient isolates. Types 1 (enterotoxigenic) and 9 (nonenterotoxigenic), were each found in the stools of two patients. All other isolates showed a dis...
Collinder E, Berge GN, Grønvold B, Lindholm A, Midtved T, Norin E.This study investigated the influence of zinc bacitracin on the intestinal flora of horses. The functionally active intestinal flora was examined in 6 horses during treatment with zinc bacitracin. Utilising gas chromatography, spectrophotometry, gel electrophoresis and paper chromatography, samples were analysed on biochemical markers reflecting the action of parts of the intestinal flora. The following 5 flora-related functions were studied in faecal samples and intestinal samples from different sections of the hindgut: conversion of cholesterol to coprostanol and of bilirubin to urobilinogen...
Yu H, Raymonda JW, McMahon TM, Campagnari AA.This article reviews the recent development of two solid-phase chemiluminescence-based techniques, fluorogenic-chemiluminescence (FCL) and electro-chemiluminescence (ECL) for detection of biological threat agents. Both techniques entail a labeled sandwich immunoassay. The objectives of this work are to develop advanced techniques for sensitive and effective detection of a target analyte, particularly in cases where the analysis includes complex samples containing multiple contaminating factors. Other important considerations in developing such detection techniques include the ease of use, the ...
Thornton J.To determine if the microclimate is detrimental to horses during international air transportation in an enclosed container. Methods: On each of two 12 h and two 24 h flights three horses were transported in an enclosed container designed to prevent exposure to insect vectors. Heart rates were monitored throughout and blood samples were collected periodically. Air in the container was sampled for bacteria and fungal spores and the temperature and relative humidity were recorded inside and outside the container periodically during the flight. On the two 12 h flights similar observations were mad...
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...
Al-Ghamdi GM, Kapur V, Ames TR, Timoney JF, Love DN, Mellencamp MA.To determine whether repetitive sequence-based polymerase chain reaction (rep-PCR) could be used to differentiate Streptococcus equi isolates, to examine S equi isolates from throughout the world, and to determine whether a horse had > 1 subtype of S equi during an outbreak of disease. Methods: An initial group of 32 S equi isolates, 63 S equi isolates from various geographic areas, and 17 S equi isolates obtained during outbreaks of disease. Methods: An aliquot of S equi genomic DNA was amplified, using enterobacterial repetitive intergenic consensus primers. Gel electrophoresis was perfor...
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...
Collinder E, Lindholm A, Midtvedt T, Norin E.The aim of this study was to investigate 6 microflora-associated characteristics (MACs) in faecal samples from horses and to compare the results with baselines previously established in other mammals. A MAC is defined as any anatomical structure, physiological, biochemical or immunological characteristic in a host, which has been acted on by microorganisms. When the active microbes are absent, as in germ-free animals and healthy newborn organisms, the corresponding characteristic is defined as germ-free animal characteristic (GAC). The MACs studied were degradation of mucin, conversion of chol...
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...
Rashmir-Raven AM, Black SS, Rickard LG, Akin M.Papillomatous digital dermatitis is a common disease in cattle. The pastern dermatitis observed in a horse shared many of the gross characteristics of papillomatous digital dermatitis in cattle. Lesions included a mixture of proliferative and erosive changes, with a verrucose appearance in some areas. Microscopic similarities included pseudoepitheliomatous and papillomatous epidermal hyperplasia with hyperkeratosis, spongiosis of the epidermis, and intraepidermal spirochetes. The horse was also concurrently infected with Pelodera strongyloides. Papillomatous digital dermatitis in cattle is ass...
Renshaw RW, Glaser AL, Van Campen H, Weiland F, Dubovi EJ.A virus that could not be identified as a previously known equine virus was isolated from the mononuclear cells of a horse. Electron microscopy revealed enveloped virions with nucleocapsid structures characteristic of viruses in the Paramyxoviridae family. The virus failed to hemabsorb chicken or guinea pig red blood cells and lacked neuraminidase activity. Two viral genes were isolated from a cDNA expression library. Multiple sequence alignments of one gene indicated an average identity of 45% as compared to Morbillivirus N protein sequences. A weaker relationship was found with Tupaia paramy...
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...
Pusterla N, Madigan JE, Chae JS, DeRock E, Johnson E, Pusterla JB.We report successful helminthic transmission of Ehrlichia risticii, the causative agent of Potomac horse fever, using trematode stages collected from Juga yrekaensis snails. The ehrlichial agent was isolated from the blood of experimentally infected horses by culture in murine monocytic cells and identified as E. risticii ultrastructurally and by characterization of three different genes.
Abdulmawjood A, Lämmler CH.The 16S rRNA gene of 39 S. equi subsp. zooepidemicus strains and two S. equi subsp. equi strains was amplified by polymerase chain reaction and subsequently digested with the restriction enzyme Hinc II. A restriction profile with two fragments with sizes of 1250 bp and 200 bp could be observed for both S. equi subsp. equi strains and for 30 of the 39 S. equi subsp. zooepidemicus strains indicating a sequence variation within the V2 region of the 16S rRNA gene of the remaining nine S. equi subsp. zooepidemicus isolates. A segment of the 16S rRNA gene including the hypervariable V2 region of 11 ...
Anzai T, Walker JA, Blair MB, Chambers TM, Timoney JF.To determine whether streptococcal pneumonia is caused by strains of Streptococcus zooepidemicus similar to those obtained from the tonsils of healthy horses. Methods: 5 tonsils from healthy horses, 8 tracheal washes and 6 lung specimens from foals with pneumonia, and 5 nasopharyngeal swab specimens from donkeys with acute bronchopneumonia. Methods: Variable M-like protectively immunogenic SzP proteins of 5 isolates of S. zooepidemicus from each tonsil and clinical specimen were compared, using immunoblots. The SzP gene of 13 isolates representative of various SzP immunoblot phenotypes from 1 ...
Gianini M, Sutter O, Burger D, Bracher V.Gastrointestinal function was assessed in normal foals before, during and after the onset of 'foal heat diarrhoea' by haematological, biochemical, microbiological and parasitological methods, and by a combined lactose tolerance-breath hydrogen excretion test. Warmblood mares (n=11) and their foals were used. The foals were assessed according to a standard protocol after birth and at regular intervals thereafter. All except one of the foals suffered from diarrhoea that started between day 8 and day 12 after birth, which lasted for 1-4 days. Rotavirus was detected in the faeces of five foals, bu...
Caballero AR, Lottenberg R, Johnston KH.Streptokinases secreted by nonhuman isolates of group C streptococci (Streptococcus equi, S. equisimilis, and S. zooepidemicus) have been shown to bind to different mammalian plasminogens but exhibit preferential plasminogen activity. The streptokinase genes from S. equisimilis strains which activated either equine or porcine plasminogen were cloned, sequenced, and expressed in Escherichia coli. The streptokinase secreted by the equine isolate had little similarity to any known streptokinases secreted by either human or porcine isolates. The streptokinase secreted by the porcine isolate had li...
Bernabe MCM, Fonseca BB, Silva MVC, Pedrosa IE, Silva MB, Sommerfeld S, de Sousa ALP, de Leva Resende BC, Sousa ACP, Dos Santos Freitas A....Endometritis is one of the main reproductive disorders in mares and due to the increasing prevalence of antibiotic resistance, the use of probiotics in the prevention and treatment of endometritis in mares has gained interest, given their potential to restore and maintain a healthy uterine microbiota. Therefore, the aim of this study was to evaluate the antimicrobial properties of total metabolites of Lactobacillus acidophilus (LA) and Lactiplantibacillus plantarum (LP) against common equine endometrial pathogenic bacteria in vitro (Acinetobacter baumannii, Escherichia coli (1), Escherichia co...
Hepworth-Warren KL, Love K.Bacterial pneumonia is a common disease in adult horses, but there are no guidelines for practitioners regarding risk factors, diagnosis, and management of the disease. The objectives of this study were to describe how a group of equine veterinarians diagnose and treat bacterial pneumonia in adult horses. A 22-question survey was distributed via multiple platforms to equine veterinarians asking questions regarding the frequency with which they identified specific clinical findings and used certain diagnostic modalities, and the approach to antimicrobial and adjunct therapy. Three hundred nine ...
Jarquín-Díaz VH, Dayaram A, Soilemetzidou ES, Desvars-Larrive A, Bohner J, Buuveibaatar B, Kaczensky P, Walzer C, Greenwood AD, Löber U.The microbial composition of host-associated microbiomes is influenced by co-evolutionary interactions, host genetics, domestication, and the environment. This study investigates the contribution of environmental microbiota from freshwater bodies to the gastrointestinal microbiomes of wild khulans (Equus hemionus hemionus, n = 21) and compares them with those of captive khulans (n = 12) and other equids-Przewalski's horse (n = 82) and domestic horse (n = 26). Using PacBio technology and the LotuS pipeline for 16S rRNA gene sequencing, we analyze microbial diversity and conduct ...
Arantes JA, Di Pietro R, Ratté M, Arroyo LG, Leclère M, Costa MC.Fecal microbiota transplantation (FMT) has been used as a treatment option for horses (Equus caballus) with gastrointestinal diseases. Several preparation and conservation protocols to improve bacterial survival have been studied in other species. Unassigned: This study aimed to evaluate the impact of oxygen exposure and different protectant solutions on bacterial viability before and after freezing using horse feces. Fecal samples from 10 healthy horses were aliquoted and diluted in cryoprotectant solutions containing antioxidants (n = 40) or 10% glycerol (n = 40). Half of the aliquots from e...
McTernan SP, Heller J, Clulow JR, Gannon L, Huang R, Tidd N, Blishen A, Hughes KJ.Salmonella enterica subsp. enterica is responsible for substantial morbidity and mortality within horse populations, worldwide. The prevalence of Salmonella shedding in faeces has largely been reported in hospital settings, with limited information from general horse populations. Further, there is little understanding of the serotypes and antibiograms of Salmonella isolates from horses in Australia. The objectives of this study were to (1) estimate the prevalence of Salmonella in stud farm horse populations, (2) determine serotypes and antibiograms for isolates, and (3) determine whether seaso...
Loublier C, Costa M, Taminiau B, Lecoq L, Daube G, Amory H, Cesarini C.Research on fecal microbiota changes during hospitalization of horses with colic is emerging. Objective: Describe changes of the fecal microbiota during hospitalization of horses with colic caused by inflammatory (INFL), simple (SIMPLE), and strangulated (STR) obstructions, and investigate associations with survival. Methods: Twenty-three horses with colic: 9 in INFL, 5 in STR, and 9 in SIMPLE groups. Seventeen horses survived, and 6 were euthanized. Methods: Prospective observational study. Fecal samples were collected on admission (D1), on days 3 (D3) and 5 (D5). Bacterial taxonomy profiling...
Hemeda AA, Zahran SA, Ali-Tammam M, Ewida MA, Kashef MT, Yassin AS, Mitra A, Youssef NH, Elshahed MS.The equine gut harbors a diverse microbial community and represents a rich source of carbohydrate-active enzymes (CAZymes). To identify and characterize potentially novel CAZymes from a horse's hindgut metagenome, shotgun metagenomic sequencing was performed on DNA extracted from a stool sample of a male horse, followed by CAZyme annotation. Here, we report on the characterization of a novel enzyme (AH2) that was identified, synthesized, cloned, and characterized from the obtained CAZyme dataset. AH2 was identified as a GH130 family member and displayed exclusive xylanase activity, a trait hit...
Allano M, Arsenault J, Archambault M, Fairbrother JH, Sauvé F.Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial infections, including in veterinary settings. Objective: To investigate the prevalence, risk factors for Staphylococcus aureus (SA) and MRSA colonization, and the duration of MRSA colonization. Methods: Elective cases admitted to the Veterinary Teaching Hospital were recruited (228 horses). Methods: A cross-sectional study was conducted over 3 years. Nasal swabs were collected at admission and cultured for SA. Methicillin-resistant isolates were identified using matrix-assisted laser desorption/ionization-time-...
Cullinane A, Nelly M, Dayot L, Lukaseviciute G, Garvey M, Healy J, Gallagher R.This study describes a comparison of the detection of rotavirus in clinical samples from foals using two commercially available rapid antigen detection (RAD) kits, with the detection of rotavirus nucleic acid via a laboratory-based, in-house, real-time reverse transcription polymerase chain reaction (RT-PCR) assay. One hundred and forty freeze-thawed samples (70 that were RT-PCR-positive and 70 that were RT-PCR-negative on original tests) submitted to the diagnostic laboratory over a seven-year period were tested in addition to 123 fresh samples (15 RT-PCR-positive and 108 RT-PCR-negative) sub...
Gravey F, Sévin C, Langlois B, Maillard K, Foucher N, Duquesne F, Léon A, Le Hello S, Petry S.Misidentifications as Klebsiella pneumoniae were observed during a French retrospective study of a necropsy-associated K. pneumoniae bacterial collection from horses. Accordingly, the present study aimed to further characterise the 12 Raoultella spp. and Klebsiella spp. strains involved in these misidentifications. The strains were identified and characterised using the Api 20E system, K. pneumoniae PCR detection, matrix-assisted laser desorption/ionisation time-of-flight mass spectroscopy and whole-genome sequencing. Antimicrobial susceptibilities were tested by the disc diffusion method with...
da Silva-Álvarez E, Gómez-Arrones V, Correa-Fiz F, Martín-Cano FE, Gaitskell-Phillips G, Carrasco JJ, Rey J, Aparicio IM, Peña FJ, Alonso JM....This study aims to unveil potential differences in the vaginal and uterine microbiomes in mares and jennies, and to identify possible mechanisms involved in uterine immune homeostasis. The microbiota was characterized using 16S rRNA sequencing, and the uterine proteome was analyzed using UHPLC/MS/MS in 18 samples from healthy mares and 14 from jennies. While taxonomic analysis revealed high interspecies similarities, β-diversity analysis showed distinct clustering, with only two vaginal taxa and five uterine taxa differing between species. Despite compositional differences, PICRUSt analysis s...
Ballados-González GG, Cruz-Romero A, Martínez-Hernández JM, Aguilar-Domínguez M, Vieira RFC, Grostieta E, Becker I, Sánchez-Montes S.Hemotropic mycoplasmas (HM) are emerging pathogens known to infect a wide range of mammals, including ungulates like horses. These infections can lead to severe haematological conditions, posing a threat to animal health and welfare. Recent studies have begun shedding light on the prevalence and impact of HM on horse populations worldwide. For instance, in Germany, Iran, Nigeria, and Brazil, at least three species of HM have been identified in horses, with a lack in knowledge in Latin American countries like Mexico. Our research aims to fill a crucial knowledge gap regarding the presence of HM...
Kuhn KG, Shelton K, Sanchez G, Zamor R, Bohanan K, Nichols M, Morris L, Robert J, Austin A, Dart B, Bolding B, Maytubby P, Vogel J, Stevenson B.West Nile Virus (WNV) is the most widespread and frequently reported mosquito-borne disease in the US, with a high risk of outbreaks. Accurate surveillance of WNV is complicated by many mild or asymptomatic infections, resulting in human cases being under-reported and disease distribution and transmission not being well understood. In this study, we investigated how wastewater surveillance can be used for monitoring WNV in Oklahoma. We analyzed samples collected from wastewater treatment facilities in 16 counties during July 1 to September 31, 2023, for the presence of WNV genetic material and...
Tian Y, Su Y, Jiang X, Su L, Zhang B, Lv F.The zoonotic pathogen subspecies (SEZ) frequently colonizes equines harmlessly but can occasionally cause disease or cross species barriers. Currently, growing evidence suggests SEZ can lead to severe clinical manifestations in horses and other animals, posing a threat to human and companion animal health. In this study, we sequenced the complete genome of the SEZ strain HT321, a novel sequence type 420 isolated from a donkey with a respiratory infection in China. Subsequently, we conducted comparative genomics, core genome single nucleotide polymorphisms (cgSNP), phylogenetic analysis multi...
Begmatov S, Beletsky AV, Mardanov AV, Lukina AP, Glukhova LB, Karnachuk OV, Ravin NV.Genome reduction and associated metabolic deficiencies have been described in various lineages of parasitic and symbiotic microorganisms that obtain essential nutrients from their partners, and in some free-living microorganisms that inhabit stable environments. The animal gut is a relatively stable ecosystem, characterized by an abundance of organic substances and a high concentration of microorganisms, which provides favorable conditions for the survival of microorganisms with reduced genomes. Metagenomic analysis of 49 samples of feces of farm animals (cows, sheep, yaks, and horses) reveale...
McGlennon AA, Verheyen KL, Newton JR, van Tonder A, Wilson H, Parkhill J, de Brauwere N, Frosth S, Waller AS.Strangles (Streptococcus equi infection) remains endemic in the UK, with ~300 laboratory diagnoses annually. Sub-clinically infected long-term carriers are considered a key driver of endemicity. Analysing genomes of circulating strains could provide valuable transmission insights of this pathogen. Objective: To determine the population structure and diversity of UK S. equi isolates and to model transmission using epidemiological and whole genome sequencing data. Methods: Retrospective cross-sectional epidemiological and genomic surveillance. Methods: A dated phylogenetic tree derived from 511...
Ghielmetti G, Stevens MJA, Schmitt S, Kittl S, Cernela N, Biggel M, Schulthess B, Keller PM, Schrenzel J, Stephan R.Rhodococcus equi is an intracellular bacterial pathogen that can cause infections in various hosts, including humans and animals. Host-associated virulence plasmids have been identified as key contributors to the pathogenicity of R. equi and potentially play a role in determining the host tropism of the bacteria. The investigation of additional clinical and environmental isolates is likely to provide novel insights into the population structure, infection pathways, and drug resistance of this important pathogen. We combined whole-genome sequencing and antimicrobial-susceptibility testing of 37...
Iduu NV, Raiford D, Cohen ND, Landrock KK, Wang C.We developed a fluorescence resonance energy transfer (FRET)-based real-time PCR (qPCR) assay coupled with high-resolution melting (HRM) analysis to differentiate subsp. (SEE) from subsp. (SEZ), two closely related equine pathogens with distinct clinical implications. The assay targets a region of the 23S rRNA gene containing single-nucleotide polymorphisms that differentiate the subspecies. By combining subspecies-specific probes with melting temperature () analysis, the assay accurately distinguished SEE, SEZ, and mixed infections without the need for post-PCR processing. The entire work...
Kurras S, Knottenbelt D, Schmelz U, Schaal T, Tischendorf T, Fuchs R, Schorling T, Koene MHW.Dermatophytosis is a common fungal skin infection in horses, particularly affecting young and immunocompromised animals. Traditional treatments often involve antifungal medications with potential side effects. Here, we present a case report that evaluated the efficacy of cold atmospheric plasma-aerosol (CAP-A) as a standalone treatment for equine dermatophytosis. Unassigned: A 2-year-old Westphalian warmblood stallion presented with confirmed dermatophyte lesions restricted to the left side of the mouth which were treated with CAP-A. Treatment was administered 2 times daily for 12 consecutive ...
Wunderlich G, Bull M, McGilchrist N, Zhao C, Ross T, Rose M, Chapman B.The equine gut microbiome is a complex and dynamic ecosystem, housing a diverse consortium of bacteria and anaerobic fungi (AF) capable of breaking down complex plant matter and converting it into vital energy sources for their host. The aim of this study was to broaden our current understanding of bacterial and AF diversity in the equine hindgut and how it differs between cohorts and responds to dietary shifts. Results: Faecal samples were collected from 48 horses and the bacteriome and anaerobic mycobiome analysed using long-read amplicon sequencing. Samples were collected from racehorses (R...
Pusterla N, Lawton K, Barnum S, Vitomirov A, Anaya S, Naranatt P, Swadia H, Mendonsa E.The objective of this study was to evaluate a point-of-care (POC) PCR assay for the detection of Salmonella spp. in pooled environmental samples collected at an equine veterinary hospital. A total of 945 environmental samples were collected from high-risk areas, including ICU and isolation stalls, high-traffic areas, treatment rooms, and surgical suites. The environmental samples were collected using drag swabs placed in selenite broth and individually incubated at 35 °C for 20 h. Following the incubation period, 1 mL of up to 10 individual environmental samples were pooled together. Each poo...
subsp. (SEZ) is a bacterium that primarily affects horses but can also infect other animals and humans. In 2021-2022, two SEZ outbreaks occurred in Abruzzo, Italy: one in humans linked to unpasteurized cheese (37 cases) and another in donkeys (4 deaths). These events led researchers to investigate SEZ in horses, donkeys, and a mule in the regions of Abruzzo and Molise, focusing on antibiotic resistance and genetic traits. A total of 490 nasal and genital swabs were collected from equids and analyzed for SEZ presence, with 61 positive samples. Isolated strains underwent antimicrobial suscepti...
Klass LG, Diekmann I, Andreotti S, Mbedi S, Sparmann S, Schenk T, Anderson HP, Bellaw J, Nielsen MK, Krücken J, von Samson-Himmelstjerna G.Strongyles, especially non-migratory Strongylidae, are the most common equine gut parasites, and typically occur in mixed infections with 10 - 20 species per host. Current knowledge on strongyle species prevalence and within-host tropism is sparse. Herein species composition of mixed strongyle infections of 12 naturally infected untreated young horses, based on strongyle eggs extracted from faeces, cultured third stage larva and luminal worms collected from ventral and dorsal colon was examined. Species were identified using a cytochrome c oxidase I (COI) metabarcoding approach allowing differ...
Köhne M, Hüsch R, Peh E, Hirnet J, Tönissen A, Müsken M, Plötz M, Kittler S, Sieme H.Bacterial infections of the genital tract are a severe problem in equine reproduction. Biofilms produced by Klebsiella (K.) pneumoniae and Pseudomonas (P.) aeruginosa present further concerns in such cases as they can limit the success of antibiotic treatments. Alternative treatment approaches are urgently needed for treating bacterial equine genital tract infections and thus, reduce antibiotic use. The present study reports on the bactericidal efficacy of both, novel K. pneumoniae- and P. aeruginosa-specific phages, in a biofilm model and in conjunction with antibiotic drugs as tested in vitr...
Basso RM, Cerri FM, Possebon FS, Braga PRC, Casas MRT, Oliveira-Filho JP, Araújo Júnior JP, Ribeiro MG, Arroyo LG, Borges AS. spp. are important pathogens of foals, causing clinical enterocolitis and sepsis. We characterized the resistance, virulence, and stress response genes in isolates from foals with or without diarrhea. isolates ( = 23) recovered from fecal samples of 16 diarrheic and 7 non-diarrheic <1-y-old foals were subjected to whole-genome sequencing. The most common serovars detected in diarrheic foals were subsp. serovars Infantis and Minnesota. Multidrug resistance was observed in 9 of 23 isolates, with 8 of the 9 from diarrheic foals. All of the isolates contained at least 2 resistance genes, ...
Núñez-Montero K, Leal K, Rojas-Villalta D, Castro M, Larronde C, Wagenknecht L, Contreras MJ.Studies on the bacterial composition of seminal samples have primarily focused on species isolated from semen and their effects on fertility and reproductive health. Culture-independent techniques, such as 16S rRNA gene sequencing and shotgun metagenomics, have revolutionized our ability to identify unculturable bacteria, which comprise >90% of the microbiome. These techniques allow for comprehensive analysis of microbial communities in seminal samples, shedding light on their interactions and roles. In this study, we characterized the taxonomic diversity of seminal microbial communities in he...
Haenni M, Châtre P, Drapeau A, Cazeau G, Troncy J, François P, Madec JY.Enterobacter hormaechei is an important pathogen in humans and animals, which, in addition to its intrinsic AmpC, can acquire a wide variety of genes conferring resistances to extended-spectrum cephalosporins (ESCs) and carbapenems (CPs). In France, human clinical outbreaks of E. hormaechei resistant to ESC or carbapenem were reported. Objective: To study E. hormaechei isolates from cats and dogs (=59) as well as from horses (n = 55) presenting a non-susceptible phenotype to beta-lactams in order to determine which clones, resistance genes and plasmids are circulating in France. Methods: E. ho...
Sasaki Y, Suzuki S, Kusaba N, Rahman N, Aikawa C, Okamura M.In recent years, reported cases of salmonellosis in cattle and horses in Hokkaido, Japan, have increased. To optimize antimicrobial therapy, we assessed the antimicrobial susceptibility of Salmonella isolates from these animals. Among 112 bovine isolates, high resistance rates were observed for streptomycin (92.0%), ampicillin (88.4%), and tetracycline (79.5%), while resistance rates for kanamycin (8.9%), ciprofloxacin (1.8%), gentamicin (0.0%), and colistin (0.0%) were low. Additionally, 18.8% of the bovine isolates were resistant to cefotaxime, and all of these cefotaxime-resistant isolates ...
Touareb D, Latifi S, Saoiabi S, Habraji L, Hammani O, Azzaoui K, Jodeh S, Yaghi S, Sabbahi R, Hammouti B, Saoiabi S.Lead (Pb²⁺) contamination in aquatic environments represents a serious global threat due to its toxicity, persistence, and non-biodegradable nature. In this study, hydroxyapatite (HA) was synthesized from equine scapula bone and investigated as a low-cost, sustainable adsorbent for Pb²⁺ removal from aqueous media. HA was thermally treated at 100 °C, 500 °C, and 900 °C to assess the effect of calcination on physicochemical and adsorption properties. Characterization techniques including XRD, FTIR, SEM/EDX, TGA and XRF confirmed structural and compositional evolution with temperature...
Sun J, Xu X, Gao S, Pan Q, Liu Z, Huang Y, Lian Y.Prevotella heparinolytica is a Gram-negative bacterium that is commonly found in the oral, intestinal, and urinary tracts. It has been extensively studied in lower respiratory tract infections in horses, which has heparinolytic activity and can secrete heparinase and further induces virulence factors in cells and causes disease. However, no such cases have been reported in humans. Methods: A 58-year-old male patient from China presented to the respiratory clinic in Suzhou with a productive cough producing white sputum for 20 days and fever for 3 days. Prior to this visit, a chest computed to...
