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.
Cattabiani F, Cabassi E, Allodi C, Gianelli F.The AA. report the results of taxonomic research conducted on the conjunctival sac of 59 horses for identification of the present bacterial flora. In the controlled animals, it was observed, at the level of the considered niche, a community constituted of normal bacterial populations, but not autochtonous in the significance they attributed from DUBOS et al., relative to the characterization of the indigenous microbiota of the intestine. The isolated normal bacterial flora seems to be constituted of: Micrococcus (subgroup 6 of Baird-Parker, M. luteus, Micrococcus spp.) isolated in 49,15% of th...
Burns SJ, Simpson RB, Snell JR.Sterile equipment was used to collect ten ejaculates from each of ten normal stallions and quantitative and qualitative bacterial counts were made within 15 min after collection. The mean bacterial population in undiluted semen was found to be 573,000 +/- 374,000 organisms/ml. The bacterial content of semen diluted with two parts sterile physiological saline, or with two parts of a cream-gelatin extender, was measured within 15 min after collection and again after 2 hr at 25 degrees C. The number of bacteria was slightly increased in the saline after 2 hr, but 1 93% and 99% reduction occurred ...
Wootton JF, Argenzio RA.The distribution of nitrogen in ligated segments of the stomach and intestine of two groups of ponies has been examined at sacrifice 2, 4, 8, and 12 h following the final 12-h scheduled feeding of diets designed to provide either 1) ample protein, or 2) limited protein plus supplemental urea as the major nitrogen source. Concentrations and total quantities of total N, NH3, urea plus NH3, and alpha-amino N were determined, and protein N was calculated by difference. Liquid marker (PEG) distribution rate constants and N concentrations were used to calculate rates of entry and exit by digesta flo...
Van Dijk JE, Van der Molen EJ, De Smidt AC.A case of avian tuberculosis in a horse, with fatal course, is reported. The animal was imported from Poland and became ill after some weeks, in the beginning showing non-specific symptoms which became more severe until death supervened. Post-mortem examination showed a generalised form of tuberculosis. The most important lesions were seen in the lungs, liver, kidneys, spleen, intestinal tract, bones, bone marrow, and the internal lymph nodes. Beside chronic proliferative tuberculosis of the organs, many exudative foci were found with remarkably abundant acid fast bacilli. Mixed lesions were s...
Argenzio RA, Stevens CE.Effects of diet and time after feeding on osmolality and inorganic ion content of gastrointestinal digesta were studied in 24 ponies. Animals, fed either a conventional or a low-protein, high-cellulose diet, were sacrificed 2, 4, 8, or 12 h after a meal. Animals fed the conventional diet showed cyclic variations in the ionic composition and osmolality of digesta with time after feeding. The most marked variations were seen in the contents of the stomach and small colon. However, results also indicated a cyclic appearance and disappearance of Na in large intestinal contents that correlated with...
Woolcock JB.Equine tonsillar tissue and the draining regional lymph nodes, as well as deep nasal swabs were examined bacteriologically. Group C streptococci, predominantly Streptococcus zooepidemicus, were shown to be present in all tissues. The most frequent site for isolation was the tonsil. Streptococcus equi was not located in any of the tissues sampled.
Oeding P, Hájek V, Marsálek E.Out of 70 S. aurew strains isolated from the anterior nares of horses, 48 (69 per cent)
belonged to the E biotype. Approximately one third of these isolates were typed with factor
sera, the 6 (35 per cent) that were typable showing 5 different patterns. All strains but one
were non-typable with the basic sets of phages for typing human and bovine staphylococci
even at RTD x 100. Without any exception the equine staphylococci of the E biotype
contained polysaccharide Aa. Sixteen biochemically different strains belonged to the biotype A, B or C. A number of different serological patterns an...
Clayton YM, Fox EC.The research article aims to investigate the mycology of dental calculus (tartar) and its potential to harbor fungal organisms that could lead to ocular infections, particularly in those involved in […]
McCarty SM, Percival SL, Clegg PD, Cochrane CA.This study outlines the potential of a novel therapeutic dressing for the management of chronic wounds. The dressing incorporates polyphosphate, a non toxic compound with a number of beneficial characteristics in terms of wound healing, in a foam matrix. The aim of this study was to identify the potential of polyphosphate incorporated in the foam dressing to sequester the activity of matrix metalloproteinases (MMPs) and proteases derived from Pseudomonas aeruginosa. Methods used included gelatin zymography and milk-casein agar plate analysis. Results have shown that this dressing is effectivel...
Moyaert H, Decostere A, Vandamme P, Debruyne L, Mast J, Baele M, Ceelen L, Ducatelle R, Haesebrouck F.Gram-negative, curved, motile bacteria (strains EqF1T and EqF2) were isolated from faecal samples from two clinically healthy horses. Both strains possessed a single, monopolar, sheathed flagellum and were urease-negative. The novel strains grew at 37 degrees C under microaerobic conditions and were positive for oxidase, catalase and alkaline phosphatase activities. The isolates reduced nitrate to nitrite, but gamma-glutamyl transpeptidase activity was not detected. The novel isolates did not grow at 42 degrees C or on media containing 1 % glycine. They were resistant to cephalotin and nalidix...
Fidani M, Casagni E, Montana M, Pasello E, Pecoraro C, Gambaro V.Bacteria frequently found in equine urine samples may cause degradation of 17beta-OH steroids. A simple liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed to evaluate the microbiological contamination of equine urine as a marker of poor storage conditions. Norethandrolone was used as the internal standard, and the linearity, sensitivity, precision and accuracy of the method were evaluated. 17beta-OH oxidation was demonstrated for testosterone, nandrolone, trenbolone and boldenone, but did not occur in alpha-epimers such as alpha-boldenone and epitestosterone, d...
Boyle AG, Rankin SC, D￮ LA, Morris D.Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as a cause of nosocomial infections in both human and veterinary medicine. Studies that examine the nasopharynx and guttural pouches of the horse as carriage sites for MRSA have not been reported. Objective: MRSA colonizes the nasopharynx and guttural pouch of horses. To determine the prevalence of MRSA in equine nasopharyngeal wash (NPW) and guttural pouch lavage (GPL) samples in a field population of horses. Methods: One hundred seventy-eight samples (123 NPW and 55 GPL) from 108 horses. Methods: Prospective study. Samples were...
Duchesne R, Castagnet S, Maillard K, Petry S, Cattoir V, Giard JC, Leon A.This study aimed to analyse antimicrobial susceptibility evolution of equine pathogens isolated from clinical samples from 2006-2016. A collection of 25 813 bacterial isolates was studied, clustered according to their origins (respiratory tract, cutaneous, genital and other), and analysed for their antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.6%), Escherichia coli (20.0%), Staphylococcus aureus (7.8%), Pseudomonas aeruginosa (4.0%), Enterobacter spp. (3.4%), Klebsiella pneumoniae (2.4%), and Rhodococcus equi ...
Hopper N, Singer E, Henson F.The exact aetiology and pathogenesis of microdamage-induced long bone fractures remain unknown. These fractures are likely to be the result of inadequate bone remodelling in response to damage. This study aims to identify an association of osteocyte apoptosis, the presence of osteocytic osteolysis, and any alterations in sclerostin expression with a fracture of the third metacarpal (Mc-III) bone of Thoroughbred racehorses. Methods: A total of 30 Mc-III bones were obtained; ten bones were fractured during racing, ten were from the contralateral limb, and ten were from control horses. Each Mc-II...
Ayoub C, Arroyo LG, MacNicol JL, Renaud D, Weese JS, Gomez DE.The association of microbiota with clinical outcomes and the taxa associated with colitis in horses remains generally unknown. Objective: Describe the fecal microbiota of horses with colitis and investigate the association of the fecal microbiota with the development of laminitis and survival. Methods: Thirty-six healthy and 55 colitis horses subdivided into laminitis (n = 15) and non-laminitis (n = 39, 1 horse with chronic laminitis was removed from this comparison) and survivors (n = 27) and nonsurvivors (n = 28). Methods: Unmatched case-control study. The Illumina MiSeq platform tar...
Hans A, Gaudaire D, Manuguerra JC, Leon A, Gessain A, Laugier C, Berthet N, Zientara S.This study shows that an unbiased amplification method applied to equine arteritis virus RNA significantly improves the sensitivity of the real-time reverse transcription-quantitative PCR (RT-qPCR) recommended by the World Organization for Animal Health. Twelve viral RNAs amplified using this method were hybridized on a high-density resequencing microarray for effective viral characterization.
Intemann S, Reckels B, Schubert DC, Wolf P, Kamphues J, Visscher C.Evidence has already been provided that feed-borne mold spores and endotoxins can trigger chronic, non-infectious respiratory disease if inhaled. Furthermore, deficiencies in feed microbiology are suspected to trigger gastrointestinal and liver disorders in horses, but the connection needs further clarification. Most of the previous studies regarding horse feed hygiene focused on forage, whereas research regarding hygienic quality of concentrates is scarce. In the present study, results of reports on hygienic quality of compound feed and cereals for horses were evaluated secondarily. Results i...
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...
Westgate SJ, Percival SL, Knottenbelt DC, Clegg PD, Cochrane CA.Horse wounds have a high risk of becoming infected due to their environment. Infected wounds harbour diverse populations of microorganisms, however in some cases these microorganisms can be difficult to identify and fail to respond to antibiotic treatment, resulting in chronic non-healing wounds. In human wounds this has been attributed to the ability of bacteria to survive in a biofilm phenotypic state. Biofilms are known to delay wound healing, principally due to their recalcitrance towards antimicrobial therapies and components of the innate immune response. This study describes the presenc...
Kaspar U, von Lützau K, Schlattmann A, Rösler U, Köck R, Becker K.Colonization with multidrug-resistant organisms (MDROs) belonging to the genus Staphylococcus and the order Enterobacterales poses a particular threat to populations at risk. While previous studies focused on MDRO carriage among livestock or companion animals, respective epidemiological data on the general equine population are limited. Here, carriage of methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E) in non-hospitalized horses living on private farms in the rural area in Northwest Germany was assessed. Intran...
Long MT, Goetz TE, Whiteley HE, Kakoma I, Lock TE.Two pregnant mares diagnosed as having equine monocytic ehrlichiosis based on history, clinical signs, and high serum antibody titers to Ehrlichia risticii aborted subsequent to recovery from illness. Mare 1 and mare 2 experienced clinical illness at 120 and 143 days of gestation and aborted at 203 and 226 days of gestation, respectively. The fetuses were expelled in fresh condition, and both mares retained their placentas upon abortion. Gross findings for the fetuses included meconium staining and petechiation of external surfaces. Internally, there was increased volume of feces within the sm...
Chanter N, Collin N, Holmes N, Binns M, Mumford J.The 16S-23S RNA gene intergenic spacers of isolates of Streptococcus equi (n = 5), S. zooepidemicus (n = 5), S. equisimilis (n = 3) and S. dysgalactiae (n = 2) were sequenced and compared. There were distinct regions within the spacer, arranged in the order 1-9 for all S. equi and one S. zooepidemicus isolate and 1,2 and 4-9 for the remaining isolates. Region 4 was identical to the tRNA(ala) gene found in the 16S-23S intergenic spacers of other streptococci. Regions 1, 5, 6 and 7 had distinct variations, each conserved in different isolates. However, amongst the intergenic spacers there were d...
Han H, Chen Q, Gao Y, Li J, Li W, Dang R, Lei C.In the biological process of testicular spermatogenesis, the expression and interaction of many genes are regulated by microRNAs (miRNAs). However, comparisons of miRNA expression between descended testes (DTs) and undescended testes (UDTs) are rarely done in horses. In this study, we selected two UDTs (CKY2b and GU4b) from Chakouyi (CKY) and Guanzhong (GU) horses and eight DTs (GU1-3, CKY1, CKY3, CKY2a, GU4a, and GU5). Three groups were compared to evaluate expression patterns of testicular miRNA in stallion testes. Group 1 compared normal CKY horses and GU horses (CKY1 and CKY3 vs. GU1-3). G...
Alshahrani SH, Alameri AA, Kahar F, Alexis Ramírez-Coronel A, Fadhel Obaid R, Alsaikhan F, Zabibah RS, Qasim QA, Altalbawy FMA, Fakri Mustafa Y....Recently in vivo and in vitro studies have provided evidence establishing the significance of microRNAs (miRNAs) in both physiological and pathological conditions. In this regard, the role of miRNA-128 (miR-128) in health and diseases has been found, and its critical regulatory role in the context of some viral diseases has been recently identified. For instance, it has been found that miR-128 can serve as an antiviral mediator and significantly limit the replication and dissemination of human immunodeficiency virus type 1 (HIV-1). Besides, it has been noted that poliovirus receptor-related 4 ...
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...
Gomide ACP, de Sá PG, Cavalcante ALQ, de Jesus Sousa T, Gomes LGR, Ramos RTJ, Azevedo V, Silva A, Folador ARC.Transcriptome studies on Corynebacterium pseudotuberculosis have recently contributed to the understanding about this microorganism's survival mechanisms in various hostile conditions. The gene expression profile of the C. pseudotuberculosis strain 1002 (Ovis biovar), has revealed genes that are possible candidates responsible for its maintenance in adverse environments, such as those found in the host. In another strain of this bacterium, 258 (Equi biovar), a high temperature condition was simulated, in order to verify which genes are responsible for promoting the persistence of the bacterium...
Baskerville A.For laboratory diagnosis of respiratory disease it is of overwhelming importance that the specimens taken are adequate, taken from the correct site and at the correct time. The lower regions of the respiratory tract are particularly difficult to sample but are more likely to yield the causative agent of a pneumonia. Infections involving the upper respiratory tract are much easier to sample and appropriate aspiration apparatus can be used. Consideration must be given to the timing of sample collection in relation to the life cycle of the causative micro-organism. Sampling of several animals is ...
Corona A, Cherchi R.Bacteriological surveillance is little applied in management of equine frozen semen but it is quite important to verify the microbial contamination in order to find out the chance of transmission of pathology to the mare in AI. Authors describe a qualitative and quantitative analysis for bacterial contamination on long time (3-17 years) equine frozen semen stored in liquid nitrogen. The semen checked, produced in Italy and in another Europe country, was cryopreserved in liquid nitrogen inside sealed plastic straws. One hundred and ten straws were checked out for pathogenic and no pathogenic ba...
Cui C, Li L, Wu L, Wang X, Zheng Y, Wang F, Wei H, Peng J.A healthy intestine plays an important role in the growth and development of farm animals. In small intestine, Paneth cells are well known for their regulation of intestinal microbiota and intestinal stem cells (ISCs). Although there has been a lot of studies and reviews on human and murine Paneth cells under intestinal homeostasis or disorders, little is known about Paneth cells in farm animals. Most farm animals possess Paneth cells in their small intestine, as identified by various staining methods, and Paneth cells of various livestock species exhibit noticeable differences in cell shape, ...
Makrai L, Fodor L, Hajtós I, Varga J, Dénes B.Three new serotypes were found among Rhodococcus equi strains, which could not be assigned into any of the seven serotypes of Prescott's system. Fortythree R. equi strains out of 44 previously nontypable ones isolated in Hungary could be allocated into one of the three new serotypes using the agar gel immunodiffusion (AGID) test. The three new suggested serotypes are serotype 8 (proposed reference strain: HNCMB-138003), serotype 9 (proposed reference strain: HNCMB-138004) and serotype 10 (proposed reference strain: HNCMB-138005). Hyperimmune sera produced in rabbits against the new serotypes a...
Bleumink-Pluym NM, van Dijk L, van Vliet AH, van der Giessen JW, van der Zeijst BA.The 16S ribosomal DNA sequence of Taylorella equigenitalis (formerly Haemophilus equigenitalis), the causative organism of contagious equine metritis, was determined. A phylogenetic analysis of this sequence revealed a phylogenetic position of T. equigenitalis in the beta subclass of the class Proteobacteria apart from the position of Haemophilus influenzae, which belongs to the gamma subclass of Proteobacteria. A close phylogenetic relationship among T. equigenitalis, Alcaligenes xylosoxidans, and Bordetella bronchiseptica was detected; Spirillum volutans and Chromobacterium fluviatile (Iodob...
Wagnerová P, Sak B, McEvoy J, Rost M, Sherwood D, Holcomb K, Kváč M.The prevalence of Cryptosporidium and microsporidia in feral horses, which have minimal contact with livestock and humans, is not currently known. We report the findings of a study on Cryptosporidium and microsporidia in 34 Mustangs and 50 Chincoteague ponies in the USA. Fecal samples were screened for presence of Cryptosporidium spp. by analysis of the small-subunit rRNA (SSU) and 60-kDa glycoprotein (gp60) genes, and Enterocytozoon bieneusi and Encephalitozoon spp. by analysis of the ribosomal internal transcribed spacer region (ITS). Cryptosporidium spp. and E. bieneusi were detected in 28/...
Haerdi-Landerer MC, Suter MM, Steiner A, Wittenbrink MM, Pickl A, Gander BA.For the treatment of septic arthritis in large animals, the local application of antibiotics as a slow release system may be an appropriate means to reach high local bioactivity and low systemic side effects and drug residues. In this study, doxycycline microspheres were developed and tested in vitro for their drug-release properties, suitability for intra-articular application and antimicrobial activity. Methods: The development of a slow release system was achieved by microencapsulation of the drug into poly(lactide-co-glycolide) microspheres by a novel ultrasonic atomization method. Drug el...
Hüthwohl H, Weiss R, Schmeer N, Schliesser T.Classification based on biochemical characteristics of 389 strains of plasma-coagulase-negative (plc-) staphylococci isolated from the genital tract of mares and stallions resulted in the following distribution of species: St. sciuri 130 (33.4%), St. equorum 42 (10.8%), St. xylosus 16 (4.1%), St. epidermidis 35 (9.0%), St. simulans 24 (6.2%), St. haemolyticus 33 (8.5%), St. warneri 18 (4.6%), St. lentus 12 (3.1%), St. hyicus 11 (2.8%). Strains of St. cohnii, St. capitis, St. gallinarum, St. saprophyticus and St. hominis have only been found sporadically (a. 1%). 48 (12.3%) strains could not be...
Wongtawan T, Narinthorn R, Sontigun N, Sansamur C, Petcharat Y, Fungwithaya P, Saengsawang P, Blackall PJ, Thomrongsuwannakij T.Antimicrobial resistance (AMR) is a significant threat to global health and development. Inappropriate antimicrobial drug use in animals cause AMR, and most studies focus on livestock because of the widespread use of antimicrobial medicines. There is a lack of studies on sports animals and AMR issues. This study aimed to characterize the AMR profile of E. coli found in sports animals (fighting cocks, fighting bulls, and sport horses) and soils from their environment. Unassigned: Bacterial isolation and identification were conducted to identify E. coli isolates recovered from fresh feces that w...
Jacks SS, Giguère S, Nguyen A.The objective of this study was to determine in vitro activities of azithromycin (AZM), clarithromycin (CLR), and 20 other antimicrobial agents against Rhodococcus equi and other common equine bacterial pathogens. A total of 201 bacterial isolates from various equine clinical samples were examined. CLR was more active than AZM against R. equi, with MICs at which 90% of the isolates were inhibited of 0.12 and 1.0 micro g/ml, respectively. Other antimicrobial agents highly active against at least 90% of R. equi isolates in vitro included rifampin, gentamicin, and imipenem. Both AZM and CLR showe...
van Balen J, Mowery J, Piraino-Sandoval M, Nava-Hoet RC, Kohn C, Hoet AE.The role that environmental contamination might play as a reservoir and a possible source of Methicillin-resistant Staphylococcus aureus (MRSA) for patients and personnel at equine veterinary hospitals remains undefined, as the environment has only been monitored during outbreaks or for short periods. Therefore, the objectives of this study were to determine the monthly presence, distribution, and characteristics of environmental MRSA at an equine hospital, and to establish patterns of contamination over time using molecular epidemiological analyses. For this purpose, a yearlong active MRSA su...
Ortega-Ferrusola C, González-Fernández L, Muriel A, Macías-García B, Rodríguez-Martínez H, Tapia JA, Alonso JM, Peña FJ.In an attempt to evaluate the possible relationship between the microbial flora in the stallion ejaculate and its ability to freeze,three ejaculates from five stallions were frozen using a standard protocol. Before freezing, an aliquot was removed for bacteriological analysis. Bacterial growth was observed in all the ejaculates studied. The isolated microorganisms were:Staphylococcus spp. and Micrococcus spp. (in all the stallions), beta-haemolytic Streptococcus (in stallions 3 and 4), Corynebacterium spp. (in stallions 1, 3-5), Rhodococcus spp. (in stallion number 2), Pseudomonas spp. (in sta...
