Topic:Microbiology
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.
Comparison of the clinical, microbiological, radiological and haematological features of foals with pneumonia caused by Rhodococcus equi and other bacteria. The purpose of this study was to compare the clinical, microbiological, radiological, haematological and cytological features of foals with pneumonia caused by Rhodococcus equi infection and with other bacteria, in order to provide markers for early diagnosis and treatment. A retrospective study of 113 cases of bacterial pneumonia was undertaken. Although there was considerable overlap in the affected populations, foals with R. equi pneumonia were significantly younger and had higher respiratory rates. Radiological evidence of thoracic abscessation had a sensitivity of 71% and a specificity of...
Eumycetoma caused by Madurella mycetomatis in a mare. A case of equine eumycotic mycetoma caused by Madurella mycetomatis is described. This is the first report of M. mycetomatis as the etiologic agent of human or animal infections in Israel. The definitive identification of the isolate was established by molecular methods. In addition the mold was cultured on various media through which we found that its growth rate was significantly augmented on incubation on trypticase soy agar, more so if horse serum was added to this medium. Sixteen previously published cases defined by the authors as mycetoma in horses are briefly reviewed. Among these, onl...
A first report on the microbial colonisation of the equine oesophagus. Based on cryo-SEM, standard and high resolution TEM, glycoconjugate histochemistry, and microbiological differentiation, the present study demonstrates the colonisation of the epithelium of the equine oesophagus with microorganisms. As particularly apparent using cryo-SEM to illustrate natural conditions, the present microbiota were clearly dominated by bacteria, forming a one-layer system, as attached to and embedded in concentrated mannose/mannan substances covering the outer stratum corneal cells. Bacterial numbers ranged from 5600 to 7200 per mm(2) in the central part of the oesophagus, th...
Proliferation of Streptococcus zooepidemicus and Pseudomonas aeruginosa within a simulated subpalpebral lavage flushed with equine serum. To evaluate whether equine serum administered via a simulated subpalpebral lavage system (SPL) supports proliferation of Streptococcus zooepidemicus or Pseudomonas aeruginosa within the tubing. Methods: A sterile i.v. catheter with injection cap was inserted into sterilized silicone tubing (Mila). To mimic an SPL within the dorsal conjunctival fornix, the tubing was secured to an elevated platform. The tip of the tubing extended from the platform into a vial containing culture medium just inoculated with approximately 1.5 x 10(8) CFU/mL P. aeruginosa or S. zooepidemicus. To mimic administratio...
Methicillin-resistant coagulase negative staphylococci isolated from horses. A methicillin-resistant (MR) Staphylococcus epidermidis strain was isolated from a saddle horse affected by osteolysis. MR coagulase-negative staphylococci (MRCNS) were isolated from 11 of 14 (78.8%) horses housed in the same riding club. By typing of the SCCmec region, almost the strains displayed a non typeable (NT) pattern and possessed the ccr type 2. Altogether, the high prevalence of MRCNS and the detection of NT SCCmec types support the hypothesis that horses may represent a reservoir of MRCNS for humans and that equine MRCNS may act as potential source of resistance genes for other sta...
Immunohistological demonstration of Rhodococcus equi in a trotter foal. A 3-month-old female trotter foal was euthanized due to severe dyspnoea. Pathomorphologically a chronic granulomatous to necrotizing pneumonia was found and Rhodoccocus (R.) equi was isolated microbiologically. An immunohistological method using a murine monoclonal antibody against a 15-17 kDa antigen of virulent R. equi was established in formalin-fixed and paraffin-embedded tissue sections using various antigen retrieval techniques to optimize the staining results. Microwave treatment was most suitable for the demonstration of bacterial antigen localized predominantly in intralesional macrop...
A zoonotic genotype of Enterocytozoon bieneusi in horses. This is the first report of Enterocytozoon bieneusi in an equid species. Feces from 195 horses from 4 locations in Colombia were examined for E. bieneusi by polymerase chain reaction. Of these, 21 horses (10.8%) were found positive for E. bieneusi . The prevalence of E. bieneusi in horses 1 yr of age (2.5%). No significant differences in prevalence were observed between male (13.7%) and female horses (9%). Sequencing of the internal transcribed spacer region of the SSUrRNA locus identified 3 genotypes. Two genotypes appear to be unique to horses and were named Horse 1 and Horse 2. A third geno...
Use of quantitative real-time PCR for the detection of Salmonella spp. in fecal samples from horses at a veterinary teaching hospital. A quantitative real-time (RT)-PCR assay was developed to detect Salmonella spp. in the feces of 911 equine species admitted to a veterinary hospital. Fresh feces and feces enriched for 24h in selenite broth were assessed by conventional culture and by RT-PCR targeting the Salmonella invA gene. The detection limit for the RT-PCR assay was 3 and 10 organisms, respectively, when spiked samples were purified from selenite broth and feces. The analytical specificity was 100% based on the detection of a panel of 40 salmonella serotypes from five serogroups and the lack of cross-reactivity with non-r...
Lactobacillus and Bifidobacterium diversity in horse feces, revealed by PCR-DGGE. Lactobacillus equi, Lactobacillus hayakitensis, Lactobacillus johnsonii, and Weissella confusa/cibaria were the dominant species in 12 South African horses. The Bifidobacterium-group was detected in the feces of only one of the 12 horses. Sequencing of the nested-PCR amplicon identified the Bifidobacterium-group as Parascardovia denticolens. Cell numbers of L. equi, L. hayakitensis, and W. confusa/cibaria were consistent in all samples. P. denticolens, Bifidodobacterium pseudolongum, and a phylogenetic relative of Alloscardovia omnicolens were rarely detected. L. equigenerosi, a dominant speci...
Viability of Rhodococcus equi and Parascaris equorum eggs exposed to high temperatures. There is great concern about the potential pathogen contamination of horse manure compost spread in the same fields horses graze in. To ensure that pathogen destruction occurs, temperatures need to be sufficiently high during composting. Here, we investigated the survival rate of two marker organisms, Rhodococcus equi and Parascaris equorum eggs, exposed to temperatures potentially encountered during horse manure composting. Our results show that the time required to achieve a 1 log10 reduction in R. equi population (D-value) are 17.1 h (+/-1.47) at 45 degrees C, 8.6 h (+/-0.28) at 50 degrees ...
Equine herpesvirus type 1 (EHV-1) utilizes microtubules, dynein, and ROCK1 to productively infect cells. To initiate infection, equine herpesvirus type 1 (EHV-1) attaches to heparan sulfate on cell surfaces and then interacts with a putative glycoprotein D receptor(s). After attachment, virus entry occurs either by direct fusion of the virus envelope with the plasma membrane or via endocytosis followed by fusion between the virus envelope and an endosomal membrane. Upon fusion, de-enveloped virus particles are deposited into the cytoplasm and travel to the nucleus for viral replication. In this report, we examined the mechanism of EHV-1 intracellular trafficking and investigated the ability of EH...
That horse bit me: zoonotic infections of equines to consider after exposure through the bite or the oral/nasal secretions. Millions of individuals are in contact with horses through occupational or recreational activities. Injuries from horses are responsible for over 100,000 emergency room visits each year in the United States. Although various types of traumatic injuries related to direct contact with horses are well described, roughly 3% to 4.5% of all reported injuries are due to bites by equines. The immediate injuries are commonly either blunt or penetrating trauma to local tissue; however, the bite exposure may also transmit a microbial agent of equine origin that can lead to a zoonotic infection. In almost...
Does the microbial flora in the ejaculate affect the freezeability of stallion sperm? 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...
Lactobacillus equicursoris sp. nov., isolated from the faeces of a thoroughbred racehorse. We previously isolated five strains of putative lactobacilli from the faeces of a thoroughbred horse (a 4-year-old male). Of the five strains, four were identified as members of existing Lactobacillus species; however, sequence analysis of the 16S rRNA gene revealed that the fifth isolate, DI70(T), showed approximately 97 % identity (1325/1366 bp) with the type strain of Lactobacillus delbrueckii. Therefore, we considered the possibility that DI70(T) represents a novel species of the genus Lactobacillus. Cells of strain DI70(T) were Gram-stain-positive, catalase-negative, non-spore-forming, no...
Streptomyces atriruber sp. nov. and Streptomyces silaceus sp. nov., two novel species of equine origin. Two actinomycete strains, NRRL B-24165(T) and NRRL B-24166(T), isolated from lesions on equine placentas in Kentucky, USA, were analysed using a polyphasic taxonomic approach. On the basis of phylogenetic analysis of 16S rRNA gene sequences, morphological observations and the presence of ll-diaminopimelic acid as the diagnostic diamino acid in whole-cell hydrolysates, the new isolates clearly belonged to the genus Streptomyces. Analyses of the phylogenetic positions of strains NRRL B-24165(T) and NRRL B-24166(T) based on 16S rRNA gene sequences of all recognized species of the genus Streptomyc...
Pharmacokinetics of intravenous ceftiofur sodium and concentration in body fluids of foals. The objectives of this study were to determine pharmacokinetics of intravenous (i.v.) ceftiofur in foals, to compare ultra-high performance liquid chromatography tandem mass spectometry (UPLC-MS/MS) and microbiologic assay for the measurement of ceftiofur concentrations, and to determine the minimum inhibitory concentration (MIC) of ceftiofur against common equine bacterial pathogens. In a cross-over design, ceftiofur sodium was administered i.v. to six foals (1-2 days-of-age and 4-5 weeks-of-age) at dosages of 5 and 10 mg/kg. Subsequently, five doses of ceftiofur were administered i.v. to six...
[The occurrence of the hindgut ciliate Blepharocorys curvigula (Ciliophora: Blepharocorythidae) from horses (Equus caballus Linnaeus, 1758) in the vicinity of Izmir]. Blepharocorys curvigula Gassovsky, 1919 found in the intestine of domestic horses (Equus caballus Linnaeus, 1758), living in the vicinity of Izmir was investigated. It was seen in nine of the thirteen horses examined (69%). This study reports the presence of Blepharocorys curvigula in the intestine of Equids for the first time in Turkey. Specimens were found to be similar to the original descriptions on the basis of morphological characters and biometric data.
Helicobacter equorum: prevalence and significance for horses and humans. Helicobacter equorum colonizes the caecum, colon and rectum of horses. The agent is highly prevalent in <6-month-old foals. In adult horses, the prevalence of H. equorum seems to be rather low, but these animals may harbour low, subdetectable numbers of this microorganism in their intestines. So far, no association could be made between the presence of H. equorum and clinical disease or intestinal lesions in adult horses. Further research is necessary to elucidate the pathogenic potential of this bacterial species towards young foals. Helicobacter equorum DNA was not detected in human faece...
The bacterial community of the horse gastrointestinal tract and its relation to fermentative acidosis, laminitis, colic, and stomach ulcers. The gastrointestinal tract of the horse has unique characteristics that make it well suited for the ingestion and utilization of roughage. The horse is considered a simple-stomached herbivore and is classed as a hindgut fermenter. The upper segments of the gastrointestinal tract resemble those of a typical simple-stomached animal. The lower have undergone modification to become voluminous and host to a large number of microbial populations similar to those of the compartmental stomach of ruminant animals. The main advantage of this arrangement is the ability of the horse to extract valuable nu...
Thermotolerance and multidrug resistance in bacteria isolated from equids and their environment. Sixty-nine vaginal swabs and 138 rectal swabs collected from 195 equids were analysed for the presence of thermotolerant bacteria, that is, bacteria surviving at 60+/-0.1 degrees C for one hour. Thermotolerant Escherichia coli, Enterobacter species, Klebsiella pneumoniae, Proteus species and Pseudomonas species were isolated from 41, 16, nine, three and three of the 138 rectal swabs, respectively; seven of the E coli and two of the Enterobacter species isolates survived pasteurisation at 63.8+/-0.1 degrees C for 30 minutes. All except three E coli, two Enterobacter species and one Proteus spec...
Trypanosoma vivax displays a clonal population structure. African animal trypanosomiasis, or Nagana, is a debilitating and economically costly disease with a major impact on animal health in sub-Saharan Africa. Trypanosoma vivax, one of the principal trypanosome species responsible for the disease, infects a wide host range including cattle, goats, horses and donkeys and is transmitted both cyclically by tsetse flies and mechanically by other biting flies, resulting in a distribution covering large swathes of South America and much of sub-Saharan Africa. While there is evidence for mating in some of the related trypanosome species, Trypanosoma brucei...
Effect of live yeast culture supplementation on hindgut microbial communities and their polysaccharidase and glycoside hydrolase activities in horses fed a high-fiber or high-starch diet. Four cecum and right ventral colon-fistulated horses were assigned in a 4 x 4 Latin square design and fed a high-fiber (HF) or a high-starch (HS) diet with or without 10 g of Saccharomyces cerevisiae (SC; CBS 493.94) containing 4.5 x 10(9) cfu/g. The HF and HS diets consisted of pelleted feeds and long wheat straw (18.0 and 3.5 g of DM.kg(-1) of BW.d(-1), respectively) given in 2 equal meals to provide an NDF:starch ratio of 3.5 and 1.0, respectively. After a 21-d adaptation period intestinal contents were collected 4 h after the morning meal on d 23 and 25 to determine bacterial and SC concen...
In silico detection and characteristics of novel microRNA genes in the Equus caballus genome using an integrated ab initio and comparative genomic approach. The importance of microRNAs at the post-transcriptional regulation level has recently been recognized in both animals and plants. We used the simple but effective sequential method of first Blasting known animal miRNAs against the horse genome and then using the located candidates to search for novel miRNAs by RNA folding method in the vicinity (+ -500 bp) of the candidates. Here, a total of 407 novel horse miRNA genes including 354 mature miRNAs were identified, of these, 75 miRNAs were grouped into 32 families based on seed sequence identity. MiRNA genes tend to be present as clusters in som...
Microarray identification of Clostridium difficile core components and divergent regions associated with host origin. Clostridium difficile is a gram-positive, spore-forming enteric anaerobe which can infect humans and a wide variety of animal species. Recently, the incidence and severity of human C. difficile infection has markedly increased. In this study, we evaluated the genomic content of 73 C. difficile strains isolated from humans, horses, cattle, and pigs by comparative genomic hybridization with microarrays containing coding sequences from C. difficile strains 630 and QCD-32g58. The sequenced genome of C. difficile strain 630 was used as a reference to define a candidate core genome of C. difficile a...
The role of nutrition in colic. Nutritional intolerances manifesting as colic in the horse may be largely explained by divergence from the diet and ingestive behaviors to which the feral ancestors of modern domesticated equids had become accustomed and adapted. High-starch diets and abrupt dietary changes are probably foremost in the risk factors for diet-associated colic in the horse and have their basis in disruption of the stability of microbial populations resident within the equine hindgut. Although some general associations between colic and diet may be inferred from several epidemiologic studies, data derived from stu...
Biofilm evidence and the microbial diversity of horse wounds. Evidence of biofilms in human chronic wounds are thought to be responsible for preventing healing in a timely manner. However, biofilm evidence in horse wounds has not yet been documented. Consequently, this study aimed to determine whether biofilms could be detected in wounds, and to investigate the microbiology of chronic wounds in horses. Prior to analysis, wound surfaces were irrigated with 5 mL of sterile saline to remove debris. All wounds were swabbed twice (1 cm2 area) using sterile cotton-tipped swabs. In addition to this, 2 tissue biopsies were taken to investigate evidence of biofil...
Comparative assessment of human and farm animal faecal microbiota using real-time quantitative PCR. Pollution of the environment by human and animal faecal pollution affects the safety of shellfish, drinking water and recreational beaches. To pinpoint the origin of contaminations, it is essential to define the differences between human microbiota and that of farm animals. A strategy based on real-time quantitative PCR (qPCR) assays was therefore developed and applied to compare the composition of intestinal microbiota of these two groups. Primers were designed to quantify the 16S rRNA gene from dominant and subdominant bacterial groups. TaqMan probes were defined for the qPCR technique used ...
A mass spectrometric study on meloxicam metabolism in horses and the fungus Cunninghamella elegans, and the relevance of this microbial system as a model of drug metabolism in the horse. This paper describes a study where the metabolism of the non-steroidal anti-inflammatory drug meloxicam was investigated in six horses and in the filamentous fungus Cunninghamella elegans. The metabolites identified were compared between the species, and then the fungus was used to produce larger amounts of the metabolites for future use as reference material. C. elegans proved to be a good model of phase I meloxicam metabolism in horses since all four metabolites found were the same in both species. Apart from the two main metabolites, 5'-hydroxymethylmeloxicam and 5'-carboxymeloxicam, a seco...
Comparison of clinical, microbiologic, and clinicopathologic findings in horses positive and negative for Clostridium difficile infection. To compare clinical, microbiologic, and clinicopathologic findings among horses infected with Clostridium difficile that had toxin A in their feces, horses with evidence of C difficile infection that were negative for toxin A in their feces, and horses with diarrhea that were negative for C difficile infection. Methods: Cross-sectional study. Methods: 292 horses and foals with diarrhea. Methods: Feces were submitted for microbial culture and tested for the C difficile antigen glutamate dehydrogenase and for toxin A with a commercial ELISA. Results: Horses with toxin A in their feces had higher...