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.
Żak-Bochenek A, Żebrowska-Różańska P, Bajzert J, Siwińska N, Madej JP, Kaleta-Kuratewicz K, Bochen P, Łaczmański Ł, Chełmońska-Soyta A.In the gastrointestinal mucosa, there is a close cooperation between secretory immunoglobulin A (SIgA) and the composition of the microbiota, which aims to maintain homeostasis as well as act as a protective barrier. The purpose of this study was to determine the composition of microbiota and SIgA production in different parts of the digestive tract (small intestine, cecum, colon and rectum) of nine healthy horses and its reflection in the feces. For this purpose, we determined: the composition of the microbiome (by next-generation Sequencing of Hypervariable Regions V3-V4 and V7-V9 of the 16...
Bekele D, Dessalegn B, Tadesse B, Abey SL.Strangles, caused by Streptococcus equi subspecies equi, is a highly infectious disease of equines causing major health issues and financial losses. The aim of the study was to detect the presence of the SeM gene in Streptococcus equi isolated from equine suspected of having strangles. A cross-sectional study design was conducted from July to December 2022 in five districts of the central Gondar zone, Ethiopia. One-hundred sixty swab samples were taken from animals that had been clinically suspected. The SeM gene was detected using polymerase chain reaction, and the antimicrobial susceptibilit...
Kikuchi M, Murase H, Urata K, Ishige T, Nagata SI, Tozaki T, Kakoi H, Ishiguro-Oonuma T, Kizaki K.Circulating microRNAs (miRNAs) are stable in body fluids and can serve as biomarkers for various diseases and physiological states. Although pregnancy-related miRNAs have been identified in various mammals, studies on parturition-related circulating miRNAs in mares are limited. Therefore, this study aimed to identify parturition-related miRNAs and examine their potential applications in the prediction of parturition date. miRNAs were extracted from the plasma of Thoroughbred mares 30 days (295-326 days pregnant) and 5 (323-352 days pregnant) - 0 (328-357 days pregnant) days before parturition,...
Veiga RF, Clarindo LN, Fensterseifer AL, Pompelli LH, Sfaciotte RAP, Schwarz DGG, Eloy LR, Ferraz SM.The objective of this study was to determine the prevalence of Streptococcus equi (S. equi subsp equi and S. equi subsp zooepidemicus) in the state of Santa Catarina and evaluate the antimicrobial susceptibility of the isolates. For this, 420 nasal swab samples were collected from randomly selected horses. Isolation and phenotypic characterization of the bacteria were performed by sowing on 5% sheep blood agar, followed by analysis of morphotinctorial characteristics and biochemical analysis. To differentiate the main beta-hemolytic Streptococcus in horses, the fermentation profiles of the sug...
Sävilammi T, Alakangas RR, Häyrynen T, Uusi-Heikkilä S.Gastrointestinal disorders are common and debilitating in horses, but their diagnosis is often difficult and invasive. Fecal samples offer a non-invasive alternative to assessing the gastrointestinal health of horses by providing information about the gut microbiota and inflammation. In this study, we used 16S sequencing to compare the fecal bacterial diversity and composition of 27 healthy horses and 49 horses diagnosed with inflammatory bowel disease (IBD). We also measured fecal calprotectin concentration, a marker of intestinal inflammation, in healthy horses and horses with IBD. We found ...
Semik-Gurgul E, Pawlina-Tyszko K, Gurgul A, Szmatoła T, Rybińska J, Ząbek T.DNA methylation and microRNA (miRNA) expression are epigenetic mechanisms essential for regulating tissue-specific gene expression and metabolic processes. However, high-resolution transcriptome, methylome, or miRNAome data is only available for a few model organisms and selected tissues. Up to date, only a few studies have reported on gene expression, DNA methylation, or miRNA expression in adult equine tissues at the genome-wide level. In the present study, we used RNA-Seq, miRNA-seq, and reduced representation bisulfite sequencing (RRBS) data from the heart, lung, and liver tissues of healt...
Mazzuchini MP, Lisboa FP, Segabinazzi LG, Canisso IF.Endometritis is the leading cause of mare subfertility. Most mares respond to standard therapy, but alternative therapies have been developed for mares failing to respond. This study aimed to investigate a commercially available, yet unassessed, product labeled as a uterine sanitizer to determine the in vitro antimicrobial activity against microorganisms associated with endometritis and its in vitro stability to dilute antibiotics. In experiment 1, the microdilution broth technique and antimicrobial effects were assessed against Escherichia sp, Staphylococcus sp., Klebsiella sp., Pseudomonas s...
Hu B, Gao S, Zhang H, Li Q, Li G, Zhang S, Xing Y, Huang Y, Han S, Tian Y, Zhang W, He H.Rhodococcus equi (R. equi) is a Gram-positive zoonotic pathogen that frequently leads to illness and death in young horses (foals). This study presents the complete genome sequence of R. equi strain BJ13, which was isolated from a thoroughbred racehorse breeding farm in Beijing, China. Results: The BJ13 genome has a length of 5.30 Mb and consists of a complete chromosome and a plasmid measuring 5.22 Mb and 0.08 Mb, respectively. We predicted 4,929 coding gene open reading frames, along with 52 tRNAs and 12 rRNAs. Through analysis of mobile genetic elements, we identified 6 gene islands and ...
Verhaar N, Reineking W, Hewicker-Trautwein M, Grages AM, Kästner SBR, Geburek F.To evaluate the use of laser Doppler flowmetry and spectrophotometry (LDFS) for large intestinal viability assessment in horses with naturally occurring large intestinal strangulations. Methods: By use of LDFS, intestinal microperfusion was quantified as tissue oxygen saturation (tSo2), hemoglobin (tHB), and blood flow (tBF) in cases with large colon volvulus and small colon strangulations undergoing colic surgery (n = 17). Intestinal biopsies were taken from the pelvic flexure in all large colon cases and in small colon cases that underwent intraoperative euthanasia. Measurements were compare...
Leng J, Moller-Levet C, Mansergh RI, O'Flaherty R, Cooke R, Sells P, Pinkham C, Pynn O, Smith C, Wise Z, Ellis R, Couto Alves A, La Ragione R....Gut bacterial communities have a profound influence on the health of humans and animals. Early-life gut microbial community structure influences the development of immunological competence and susceptibility to disease. For the Thoroughbred racehorse, the significance of early-life microbial colonisation events on subsequent health and athletic performance is unknown. Here we present data from a three-year cohort study of horses bred for racing designed to explore interactions between early-life gut bacterial community structure, health events in later life and athletic performance on the race...
Szkolnicka K, Mituniewicz-Małek A, Dmytrów I, Bogusławska-Wąs E.During the last years, growing interest in the use of mare's milk in food production is observed. The subject of the study was to evaluate the feasibility of mare's milk for the production of yogurt ice cream and synbiotic ice cream. Four variants of mare's milk ice cream were developed: ice cream with yogurt bacteria without inulin (YO) and with 2% of inulin (YO+I), synbiotic ice cream with 2% inulin and Lacticaseibacillus rhamnosus (LCR+I) and with Lactiplantibacillus plantarum (LP+I). Ice creams were enriched with inulin in order to evaluate its influence on the viability of LAB and on the ...
Bell J, Raidal S, Peters A, Hughes KJ.Management of diarrhoea in horses is usually non-specific and supportive. Faecal microbiota transplantations (FMT) are used to manage dysbiosis in horses with diarrhoea. There are few studies investigating the effects of storage on prepared FMT solutions. This study was an in vitro non-randomised controlled experiment that investigated the effects of FMT solution preparation and storage on the faecal microbiota. Fresh faeces were collected from five healthy adult horses and used for DNA extraction and preparation of FMT. From each FMT, seven aliquots were collected and DNA was extracted immedi...
Woo PCY, Mheiri FA, Cavalleri J, Joseph S, Tang JYM, Joseph M, Tsang CC, Lau SKP, Wernery U.Epizootic lymphangitis (EL) is a highly prevalent and contagious infectious disease affecting horses in many parts of Ethiopia caused by Histoplasma capsulatum sensu lato ('var. farciminosum'). In this study, 12 suspected isolates of H. capsulatum sensu lato or yeasts unidentified by conventional biochemical tests isolated from Ethiopian horses with EL were characterised by ITS sequencing. Six of the 12 isolates were identified to be members of H. capsulatum sensu lato and the other six were Pichia kudriavzevii (synonym: Candida krusei) (n = 3), Trichosporon asahii (n = 1), Geotrichum silv...
Scholtz M, Guthrie AJ, Newton R, Schulman ML.Three bacteria extensively acknowledged as venereal pathogens with the potential to induce endometritis include Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), specific strains of Pseudomonas aeruginosa, and certain capsule types of Klebsiella pneumoniae. The United Kingdom's Horserace Betting Levy Board recommends pre-breeding screening for these bacteria in their International Codes of Practice and >20 000 samples are tested per annum in the United Kingdom alone. While the pathogenesis and regulatory importance of CEM are well established, an evaluation...
Froidurot A, Jacotot E, Julliand S, Grimm P, Julliand V.Despite their low quantity and abundance, the cellulolytic bacteria that inhabit the equine large intestine are vital to their host, as they enable the crucial use of forage-based diets. Fibrobacter succinogenes is one of the most important intestinal cellulolytic bacteria. In this study, Fibrobacter sp. HC4, one cellulolytic strain newly isolated from the horse cecum, was characterized for its ability to utilize plant cell wall fibers. Fibrobacter sp. HC4 consumed only cellulose, cellobiose, and glucose and produced succinate and acetate in equal amounts. Among genes coding for CAZymes, 26% o...
Morais DA, Nunes BC, Barnabé NNC, Anjos DM, Bezerra CS, Costa DF, Santos CSAB, Azevedo SS, Alves CJ.Leptospirosis is an anthropozoonosis of economic and public health importance, caused by bacteria of the genus Leptospira. Horses are deemed important in its transmission chain due to their proximity to humans, and because the species is often asymptomatic, making these animals potential silent reservoirs. In this context, the objectives of this study were to determine the prevalence of seropositive horses for Leptospira spp., and to identify the presence of Leptospira spp. serogroups and antibody titers, the occurrence of areas with higher density of infection cases and demographic characteri...
Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA.The equine industry holds substantial economic importance not only in the USA but worldwide. The occurrence of various infectious bacterial diseases in horses can lead to severe health issues, economic losses, and restrictions on horse movement and trade. Effective management and control of these diseases are therefore crucial for the growth and sustainability of the equine industry. While antibiotics constitute the primary treatment strategy for any bacterial infections in horses, developing resistance to clinically important antibiotics poses significant challenges to equine health and welfa...
Bachmann M, Schusser GF, Wensch-Dorendorf M, Pisch C, Bochnia M, Santo MM, Netzker H, Woitow G, Thielebein J, Kesting S, Riehl G, Greef JM....Concentrations of starch, mono- and disaccharides, fructans, hemicellulose and cellulose were analysed in feed and gastric digesta of horses in relation to acid insoluble ash as a marker indigestible in the stomach. Twenty-four horses were allocated to pasture 24 h/d (PST; n = 4), hay ad libitum (HAY; n = 8), hay ad lib. and oats at 1 g starch/kg body weight (BWT)/meal (OS1; n = 6) and hay ad lib. and oats at 2 g starch/kg BWT/meal (OS2; n = 5). One horse was excluded from the analysis. The horses were fed the ration a minimum of 34 days. Following euthanasia and dissection, digesta was sample...
Grzyb J, Podstawski Z, Bulski K.Horses stay in different types of stables; especially during the cold season, they stay inside for most of the day. A stable is also a place where many people spend quite a lot of time either as employees who care for and train horses or as equine enthusiasts. Keeping horses in stables causes their constant exposure to high concentrations of particulate matter (PM) and molds in the air inside these facilities. The study was conducted in Udórz Stud Farm located in the southern region of Poland. It was carried out in two different types of stables: three runners and two box stables. The study c...
Lacante SA, Jiang C, Mustamir AA, Mizuno T, Bi X, Syafruddin D, Tokoro M., a human intestinal protozoan parasite of the diplomonad group, has been overlooked because of its commensal features; therefore, molecular studies on this parasite are limited. To address this gap, we designed a molecular screening protocol using polymerase chain reaction (PCR) and DNA sequencing targeting the 18S small subunit ribosomal RNA gene and applied this screening method to the molecular epidemiological analysis of spp. in humans and various livestock. We validated our methodology using stool samples collected from 215 humans and 270 animal hosts (buffaloes, pigs, dogs, goats, hors...
Stothart MR, McLoughlin PD, Medill SA, Greuel RJ, Wilson AJ, Poissant J.Gut microbiomes are widely hypothesised to influence host fitness and have been experimentally shown to affect host health and phenotypes under laboratory conditions. However, the extent to which they do so in free-living animal populations and the proximate mechanisms involved remain open questions. In this study, using long-term, individual-based life history and shallow shotgun metagenomic sequencing data (2394 fecal samples from 794 individuals collected between 2013-2019), we quantify relationships between gut microbiome variation and survival in a feral population of horses under natural...
Fanelli D, Moroni R, Sala G, Melanie P, Tarabella I, Telleschi N, Maltinti S, Giorgi M, Barsotti G, Passamonti F, Marmorini P, Rota A, Camillo F....Two studies were conducted to evaluate the use of medical ozone (O) in commercial extenders for equine semen cryopreservation. In the first study (Study 1), 0, 5, and 15 µg/mL of O were added to diluents of refrigerated or frozen semen. Samples were evaluated for sperm kinematics at different time points for the chilled samples and after a thermoresistence test for the frozen/thawed samples. In the second study (Study 2), 0, 5, and 10 µg/mL of O were added to an antibiotic-free diluent for refrigerated semen for comparison with the control group in which semen was diluted in the same diluent...
Becker R, Haenssgen K, Precht C, Khoma OZ, Hlushchuk R, Koch C, Kaessmeyer S, de Preux M.Equine trigeminal-mediated headshaking is a painful neuropathic disorder comparable to trigeminal neuralgia in humans. The selective destruction of pain fibers within the trigeminal ganglion, called rhizotomy, is the surgical treatment of choice for idiopathic trigeminal neuralgia refractory to medical treatment in humans. The human trigeminal ganglion is enclosed by a dural recess called the Meckel's or trigeminal cave, in which the ganglion is surrounded by a cerebrospinal fluid (CSF)-filled subarachnoid space. During glycerol rhizotomy, glycerol is percutaneously injected in this CSF-filled...
Cho PW, Park SA, Sledge D, Gruenwald R, Townsend WM.The aim of this report was to provide a clinical description and clinical, ultrasonographic, and histologic images of a foal with microphthalmia and multiple ocular abnormalities. Methods: A 12-h old Friesian-American Paint Horse crossbred filly presented for blindness, microphthalmia and marked ventral strabismus in both eyes. Methods: A complete ophthalmic examination was performed. Ultrasound biomicroscopy and B-mode ultrasonography were performed. The globes were submitted for histopathology. Results: Ultrasound biomicroscopy demonstrated a hyperechoic cornea void of the typical epithelium...
Roberts DM, Gilger BC.Equine fungal keratitis represents a substantial portion of keratitis cases in horses, with fungal involvement identified in approximately half of all infectious keratitis cases. Despite its prevalence, more comprehensive retrospective analyses are needed to better understand this condition. Outcomes vary, with approximately two-thirds of cases achieving complete healing with retained vision, although enucleation is often necessary. Predominant pathogens include Aspergillus and Fusarium, with yeast reported in a minority of cases. Resistance to common antifungal agents among filamentous fungi ...
Long AE, Pitta D, Hennessy M, Indugu N, Vecchiarelli B, Luethy D, Aceto H, Hurcombe S.Currently, lack of standardization for fecal microbiota transplantation (FMT) in equine practice has resulted in highly variable techniques, and there is no data on the bacterial metabolic activity or viability of the administered product. The objectives of this study were to compare the total and potentially metabolically active bacterial populations in equine FMT, and assess the effect of different frozen storage times, buffers, and temperatures on an equine FMT product. Fresh feces collected from three healthy adult horses was subjected to different storage methods. This included different ...
Hu L, Li X, Li C, Wang L, Han L, Ni W, Zhou P, Hu S.The gut microbiota is a treasure trove of carbohydrate-active enzymes (CAZymes). To explore novel and efficient CAZymes, we analyzed the 4,142 metagenome-assembled genomes (MAGs) of the horse gut microbiota and found the MAG117.bin13 genome (Bacteroides fragilis) contains the highest number of polysaccharide utilisation loci sites (PULs), indicating its high capability for carbohydrate degradation. Bioinformatics analysis indicate that the PULs region of the MAG117.bin13 genome encodes many hypothetical proteins, which are important sources for exploring novel CAZymes. Interestingly, we discov...
Bell J, Raidal SL, Hughes KJ.Changes to the faecal microbiota of horses associated with administration of anthelmintic drugs is poorly defined. This study included horses with cyathostomin infection where susceptibility and resistance to oxfendazole and abamectin was known. This study assessed the changes to the faecal microbiota associated with administration of two different anthelmintics in this population. Twenty-four adult horses were included. Faecal egg counts were performed on all horses prior to random allocation into abamectin (n=8), oxfendazole (n=8) or Control groups (n=8) and at Day 14 post treatment. Faecal ...
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...
Hellman S.Enteroid cultures are three-dimensional in vitro models that reflect the cellular composition and architecture of the small intestine. One limitation with the enteroid conformation is the enclosed lumen, making it difficult to expose the apical surface of the epithelium to experimental treatments. The present study was therefore conducted to generate cultures of equine enteroids and to develop methods for culture of enteroid-derived cells on a two-dimensional plane, enabling easy access to the apical surface of the epithelium. Equine enteroids were established from small intestinal crypts with...
Arroyo LG, Staempfli H, Weese JS.Clostridium difficile is an important cause of diarrhea in horses, causing sporadic and epidemic disease of varying severity. This study evaluated the molecular characteristics of 48 C. difficile isolates recovered from diarrheic horses admitted to a veterinary hospital by using PCR-ribotyping and toxin gene profile. Additionally, feces were tested for the presence of C. difficile toxin A/B via enzyme immunosorbant assay (EIA) in 38 horses. The toxin genes tcdA, tcdB and cdtB were present in 27 (56.25%), 35 (72.91%) and 2 (4.1%) strains, respectively. Eight isolates (16.6%) were A(-)B(+) varia...
Tang L, Li Y, Srivathsan A, Gao Y, Li K, Hu D, Zhang D.Captivity maybe the only choice for survival of many endangered vertebrates, and understanding its broad effects is important for animal management and conservation, including breeding endangered species for subsequent release. Extreme environmental changes during captivity may influence survival ability in the wild. Captivity decreases gut bacterial diversity in a wide range of animals. However, most studies directly compare animals living in captivity with those in the wild, and there is a lack of understanding of effects of gradient shift in lifestyle during species reintroduction based on ...
Daly K, Shirazi-Beechey SP.Nine oligonucleotide probes complementary to conserved regions of small subunit rRNA from phylogenetically defined clusters of intestinal anaerobic bacteria were designed and evaluated for use in quantitative analysis of intestinal microflora. Optimum wash temperatures (T(w)) were determined according to the temperature of dissociation (T(d)) of each probe and target group specificity was demonstrated by comparing hybridisation to target and non-target rRNA immobilised on nylon membranes. Three probes are targeted to phylogenetic clusters of Clostridiaceae, clusters III, IV and IX, with three ...
Raspa F, Dinardo FR, Vervuert I, Bergero D, Bottero MT, Pattono D, Dalmasso A, Vinassa M, Valvassori E, Bruno E, De Palo P, Valle E.Horses reared for meat production are fed high amounts of cereal grains in comparison with horses raised for other purposes. Such feeding practice may lead to risk of poor welfare consequences. The aim of this study was to investigate the effects of two feeding practices on selected metabolic parameters and production aspects. Nineteen Bardigiano horses, 14.3 ± 0.7 months of age, were randomly assigned to two groups-one fed with high amounts of cereal grains (HCG; n = 9; 43% hay plus 57% cereal grain-based pelleted feed) vs. one fed with high amounts of fibre (HFG; n = 10; 70% hay plus...
Moore CP, Fales WH, Whittington P, Bauer L.Gram-negative bacteria were the most common microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. Pseudomonas sp, Enterobacter group, and Acinetobacter sp were the most prevalent. Fungi were cultured from 15 eyes and included 7 genera, with Aspergillus sp being the most prevalent. Ten of the eyes with fungal keratitis had been treated with corticosteroids. Eleven of 38 eyes had mixed bacterial and fungal infections. Clinically, the most severe cases were those in which Aspergillus and gram-negative bacteria existed in a mixed infection. On the basis of susceptibility testing,...
Perry E, Cross TL, Francis JM, Holscher HD, Clark SD, Swanson KS.The effects of travel stress on the equine cecal microbiota are poorly understood. We hypothesized that travel would affect the equine cecal microbiota. Cecally-cannulated horses (n = 6) were randomly assigned to one of two groups, travel (n = 3) and control (n = 3). Horses received a basal diet (Strategy, Purina Animal Nutrition) with 1.2% body weight mixed grass/alfalfa. Travel horses were transported to an unfamiliar location, stalled to simulate weekend horse show conditions, and then returned to the Southern Illinois University Equine Center. Control horses remained at the equine cente...
Scott EM, Arnold C, Dowell S, Suchodolski JS.Next generation sequencing (NGS) studies have demonstrated a rich and diverse ocular surface-associated microbiota in people that was previously undetected by traditional culture-based methods. The ocular surface microbiome of horses has yet to be investigated using NGS techniques. This study aimed to determine the bacterial composition of the ocular surface microbiome in healthy horses, and to identify whether there are microbial community changes over time and following topical antibiotic use. One eye of 12 horses was treated 3 times daily for 1 week with neomycin-polymyxin-bacitracin ophtha...
Gemensky-Metzler AJ, Wilkie DA, Kowalski JJ, Schmall LM, Willis AM, Yamagata M.To determine effects of topical antimicrobial and antimicrobial-corticosteroid preparations on the ocular flora of horses. animals: 40 horses. Methods: One eye was treated 3 times daily for 2 weeks with one of the following ointments: (1) neomycin-bacitracin-polymyxin B, (2) 0.6% prednisolone-0.3% gentamicin, (3) neomycin-polymyxin B-0.05% dexamethasone, or (4) treated (artificial tears) control. Contralateral eyes of treated control eyes served as untreated control eyes. Corneal and conjunctival specimens for bacterial and fungal cultures were collected prior to initiation of treatment, after...
Ibrahim S, Szóstek-Mioduchowska A, Skarzynski D.Bacterial infections of the genital tract are the major cause of reproductive failure in the mares. MiRNAs are important regulators of gene expression, mostly through transcriptional and translational regression. We hypothesized that LPS induced aberrant expression of miRNAs and their targets, which are involved in regulation of uterine homeostasis. Three groups of primary endometrial epithelial and stromal cells, and endometrial tissue explants were cultured. The 1 group was kept as control, while the 2 and 3 groups were challenged with low (0.5 μg/mL) or high (3.0 μg/mL) doses of Lipop...
Schoster A, Kunz T, Lauper M, Graubner C, Schmitt S, Weese JS.Overgrowth of enteric clostridia in dysbiosis in horses with colic is presumed but scarcely investigated. The objective was to provide prevalence data of Clostridium difficile and Clostridium perfringens in horses with and without gastrointestinal disease in Switzerland, and investigate microbiota differences between C. difficile shedders and non-shedders. Fecal samples were taken from healthy horses (n = 103), horses with colic (n = 98) and horses with diarrhea (n = 151). Colic horses were sampled on three days. Selective enrichment culture and molecular typing for C. difficile an...
Stothart MR, McLoughlin PD, Poissant J.Prevailing 16S rRNA gene-amplicon methods for characterizing the bacterial microbiome of wildlife are economical, but result in coarse taxonomic classifications, are subject to primer and 16S copy number biases, and do not allow for direct estimation of microbiome functional potential. While deep shotgun metagenomic sequencing can overcome many of these limitations, it is prohibitively expensive for large sample sets. Here we evaluated the ability of shallow shotgun metagenomic sequencing to characterize taxonomic and functional patterns in the faecal microbiome of a model population of feral ...
Cappelli K, Capomaccio S, Viglino A, Silvestrelli M, Beccati F, Moscati L, Chiaradia E.Endurance exercise induces metabolic adaptations and has recently been reported associated with the modulation of a particular class of small noncoding RNAs, microRNAs, that act as post-transcriptional regulators of gene expression. Released into body fluids, they termed circulating miRNAs, and they have been recognized as more effective and accurate biomarkers than classical serum markers. This study examined serum profile of miRNAs through massive parallel sequencing in response to prolonged endurance exercise in samples obtained from four competitive Arabian horses before and 2 h after the ...
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...
Cullor JS, Mannis MJ, Murphy CJ, Smith WL, Selsted ME, Reid TW.New approaches to antimicrobial therapy for ocular pathogens must overcome organisms that are resistant to current therapeutic modalities. This investigation examined the antimicrobial activity of novel antimicrobial neutrophil peptides (defensins NP-1 and NP-5) against isolates from clinical ocular microbial infections in humans and horses. The test panel of human clinical isolates included Candida albicans, an alpha-hemolytic Streptococcus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Morganella morganii. The test panel of equine pathogens included three clinical isolates of P aerug...
Kuroda T, Kinoshita Y, Niwa H, Shinzaki Y, Tamura N, Hobo S, Kuwano A.Meticillin-resistant Staphylococcus aureus (MRSA) infections have been confirmed in hospitalised Thoroughbred racehorses at the hospitals of two training centres in Japan since 2009. To investigate the source of infection, the authors examined the rate of nasal MRSA colonisation in 600 healthy Thoroughbred racehorses, 53 veterinarians and 16 office staff at the racehorse hospitals of the two training centres. MRSA was not isolated from healthy Thoroughbred racehorses or hospital office staff. However, MRSA was isolated from 16 veterinarians (30.1 per cent), and the colonisation rate was signif...
Karakulska J, Fijałkowski K, Nawrotek P, Pobucewicz A, Poszumski F, Czernomysy-Furowicz D.The aim of this study was an analysis of the staphylococcal flora of the nasal cavity of 42 healthy horses from 4 farms, along with species identification of CoNS isolates and determination of resistance to 18 antimicrobial agents, particularly phenotypic and genotypic methicillin resistance. From the 81 swabs, 87 staphylococci were isolated. All isolates possessed the gap gene but the coa gene was not detected in any of these isolates. Using PCR-RFLP of the gap gene, 82.8% of CoNS were identified: S. equorum (14.9%), S. warneri (14.9%), S. sciuri (12.6%), S. vitulinus (12.6%), S. xylosus (11....
Sangal V, Goodfellow M, Jones AL, Sutcliffe IC.Opinion 106 of the Judicial Commission has clarified the nomenclature of the taxon variously named , ' and . As a consequence, we present here the genus name and that of its nomenclatural type species, comb. nov., for valid publication and propose the reclassification of four rhodococcal species as novel combinations in the genus, namely Guo et al. 2015 comb. nov., Kämpfer . 2014 comb. nov., Li . 2015 comb. nov. and Lee . 2019 comb. nov. In addition, we note that a clinical isolate, strain 86-07 (=W8901), likely represents an additional species within the genus . Nearly a century after ...
Tomlinson JE, Wolfisberg R, Fahnøe U, Patel RS, Trivedi S, Kumar A, Sharma H, Nielsen L, McDonough SP, Bukh J, Tennant BC, Kapoor A, Rosenberg BR....Equine hepacivirus (EqHV) is phylogenetically the closest relative of HCV and shares genome organization, hepatotropism, transient or persistent infection outcome, and the ability to cause hepatitis. Thus, EqHV studies are important to understand equine liver disease and further as an outbred surrogate animal model for HCV pathogenesis and protective immune responses. Here, we aimed to characterize the course of EqHV infection and associated protective immune responses. Seven horses were experimentally inoculated with EqHV, monitored for 6 months, and rechallenged with the same and, subsequen...
Khosravi AR, Mahmoudi M.Between 1994 and 1998, a total of 790 feather, hair and skin specimens from a variety of animals with suspected dermatophytoses were studied, of which 248 (31.4%) yielded dermatophytes. The most frequent dermatophytes isolated were Microsporum canis (38.3%), Trichophyton verrucosum (31.8%), T. mentagrophytes (13.3%) and M. gypseum (7.7%). There was a significantly higher proportion of positive cultures from cats (54.8%) than dogs (8.2%), and M. canis was the most common species isolated (87.2 and 50% respectively). Trichophyton verrucosum was the most frequent causative agent of dermatophytose...
Okoko T, Blagova EV, Whittingham JL, Dover LG, Wilkinson AJ.Virulence and host range in Rhodococcus equi depends on the variable pathogenicity island of their virulence plasmids. Notable gene products are a family of small secreted virulence-associated proteins (Vaps) that are critical to intramacrophagic proliferation. Equine-adapted strains, which cause severe pyogranulomatous pneumonia in foals, produce a cell-associated VapA that is necessary for virulence, alongside five other secreted homologues. In the absence of biochemical insight, attention has turned to the structures of these proteins to develop a functional hypothesis. Recent studies have ...
Vincze S, Brandenburg AG, Espelage W, Stamm I, Wieler LH, Kopp PA, Lübke-Becker A, Walther B.Increasing numbers of companion animals suffering from infections with methicillin-resistant Staphylococcus aureus (MRSA) have been reported in the recent past. These infections are of particular concern because of the limited treatment options for MRSA and their transferability to humans. Since MRSA lineages isolated from infected companion animals often mirror typical human epidemic strains circulating in the same region, successful strategies to combat MRSA need strong and coordinated efforts from both, the human and the veterinary field according to the "One Health" concept. Hence, to iden...
Reuss SM, Giguère S.Bacterial infections of the lower respiratory tract in adult horses occur when bacteria from the nasopharynx reach the lower airways and overwhelm normal defense mechanisms. Although Streptococcus equi subsp zooepidemicus is the most commonly isolated bacterial species, mixed infections are possible. Tracheobronchial aspiration for microbiologic culture and sensitivity is suggested in cases presenting with severe clinical signs or not responding to treatment. Early intervention and appropriate antimicrobial selection results in a good prognosis for both survival and return to athletic function...
Dong HJ, Ho H, Hwang H, Kim Y, Han J, Lee I, Cho S.Equine gastric ulcer syndrome is one of the most frequently reported diseases in thoroughbred racehorses. Although several risk factors for the development of gastric ulcers have been widely studied, investigation of microbiological factors has been limited. In this study, the presence of Helicobacter spp. and the gastric microbial communities of thoroughbred racehorses having mild to severe gastric ulcers were investigated. Although Helicobacter spp. were not detected using culture and PCR techniques from 52 gastric biopsies and 52 fecal samples, the genomic sequences of H. pylori and H. ganm...
Evans K, Smith M, McDonough P, Wiedmann M.A retrospective study was conducted to determine case histories, microbiological characteristics, and molecular subtypes associated with Listeria monocytogenes infections of the eye in large animals. For selected cases, environmental L. monocytogenes contamination patterns on case farms were also evaluated to probe for potential sources and spread of listerial eye infections. Records of 170 L. monocytogenes isolates from animal infections were reviewed to determine the fraction of isolates associated with eye infections (conjunctivitis, keratitis, and uveitis) of animals and to gather informat...
Reuss SM, Cohen ND.Bacterial pneumonia is a common cause of disease in both neonatal and weanling foals. The causal organism or organisms differ with the age of the foal, should be identified via microbiologic culture, and will ultimately dictate appropriate treatment. Initial treatment in neonates should be broad spectrum and bactericidal, whereas weanling age foals may receive more targeted treatment. The combination of a macrolide antibiotic and rifampin remains the gold standard for treatment of Rhodococcus equi pneumonia; however, resistance to these antimicrobials is a concern.
Willingham-Lane JM, Berghaus LJ, Giguère S, Hondalus MK.The soil-dwelling, saprophytic actinomycete is a multihost, facultative intracellular pathogen of macrophages. When inhaled by susceptible foals, it causes severe bronchopneumonia. It is also a pathogen of pigs, which may develop submaxillary lymphadenitis upon exposure. isolates obtained from foals and pigs possess conjugative plasmids housing a pathogenicity island (PAI) containing a novel family of genes of unknown function called the virulence-associated protein or family. The PAI regions of the equine and swine plasmids differ in gene composition, with equine isolates possessing six ...
Díaz-Bertrana ML, Deleuze S, Pitti Rios L, Yeste M, Morales Fariña I, Rivera Del Alamo MM.Endometritis is one of the main causes of infertility in mares. In the present study, 363 mares with a history of repetitive infertility, and positive endometrial cytology and/or vaginal discharge were included. An endometrial swab for microbiological purposes plus sensitivity test was obtained from each mare. A positive culture was obtained in 89% of mares. The main isolated genera were (25.1%), (18.2%), (17.3%) and (12.1%). With regard to species, the most isolated microorganism was (17.3%), spp. (15.6%) and spp. (13.5%). Sensitivity tests showed that the most efficient antimicrobial ...
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...
