Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Escherichia coli
Escherichia coli (E. coli) is a bacterium commonly found in the gastrointestinal tract of horses, where it typically exists as part of the normal microbial flora. While many strains are harmless, certain pathogenic variants can cause disease in equine populations. E. coli is known to be associated with a range of conditions in horses, including colic, diarrhea, and septicemia, particularly in foals. It can also contribute to uterine infections in mares, which may impact reproductive health. This topic compiles peer-reviewed research studies and scholarly articles that explore the prevalence, pathogenic mechanisms, and clinical implications of E. coli infections in horses, as well as strategies for prevention and management.
Comparison of direct electron microscopy and enzyme immunoassay for the detection of rotaviruses in calves, lambs, piglets and foals. Direct electron microscopy (EM) and enzyme-immunoassay (rotazyme) results for the detection of rotaviruses in 346 enteric specimens from calves, lambs, piglets and foals were compared. The rotazyme test was at least 3 times more sensitive than direct EM in diagnosing infection. Rotavirus antigen was demonstrated by rotazyme in 22% of 280 scour samples and in 27% of 66 samples from non-scouring animals. There was an association between diarrhoea and higher amounts of rotavirus antigen. This prevalence of rotaviruses detected in animals with diarrhoea highlights the significant involvement of ot...
Embryonic loss in pony mares induced by intrauterine infusion of Candida parapsilosis. Pony mares which were detected pregnant by transrectal ultrasonography received a single intrauterine infusion of either sterile saline (control, n = 12 mares) or 10(6)Candida parapsilosis (treated, n = 12 mares) between Days 11 to 14 postovulation. Subsequent embryonic loss was studied by daily ultrasonography of the mare's uterus, by serum progesterone levels, by endometrial swabs for cytologic and microbiologic examination and by endometrial biopsies that were taken after embryonic loss was detected. Significantly fewer (P<0.01) embryonic losses occurred in control than in treated mares (4 ...
Hematuria caused by abdominal abscessation in a foal. A 4.5-month-old Standard-bred filly was referred for evaluation of pigmenturia. Initially, the pigmenturia had resolved with the administration of antibiotics, only to recur after their withdrawal. A dark red urine sample contained numerous RBC, WBC, and gram-negative rods (Escherichia coli). Ultrasonography revealed the right kidney to be large, with multiple cystic structures and a dilated renal pelvis and calices. Cystoscopy revealed a large blood clot within the bladder and urine coming from the left ureteral opening. Urine was not observed coming from the right ureter. It was suspected th...
Equine endotoxemia: cardiovascular, eicosanoid, hematologic, blood chemical, and plasma enzyme alterations. Ponies with electromagnetic blood flow transducers implanted around the main pulmonary and left main coronary arteries, were used to evaluate effects of chronic sublethal endotoxin on cardiac output (CO), stroke volume, and left coronary blood flow (LCBF). Plasma thromboxane (TX), as indicated by TXB2, prostacyclin as indicated by 6-keto-prostaglandin (PG) F1 alpha, and hematologic and blood chemical values also were evaluated. Over 24 hours, 2 groups of ponies were given progressively increasing IV and intraperitoneal doses of Escherichia coli lipopolysaccharide (LPS) at 0, 6, 12, and 18 hour...
Mixed venous oxygen tension as an estimate of cardiac output in anesthetized horses. The relationship between mixed venous O2 tension and cardiac output was studied in six anesthetized horses breathing 100% O2. Cardiac output, O2 consumption, mean arterial pressure, heart rate, and arterial and venous blood gases were measured after administration of xylazine or dobutamine to horses in lateral, sternal, and dorsal recumbencies. After approximately 3 hours, Escherichia coli endotoxin was administered while horses were in dorsal recumbency, and all measurements were repeated. Relationships between cardiac index (CI) and PVO2, heart rate, mean arterial pressure, jugular PVO2, and...
Functional genes for cellobiose utilization in natural isolates of Escherichia coli. The genes for utilization of cellobiose are normally cryptic in both laboratory strains and natural isolates of Escherichia coli. A survey of natural isolates of E. coli reveals that functional genes for cellobiose utilization, while rare, are present. The fraction of E. coli that utilized cellobiose ranged from less than 0.01% in human fecal samples to 7% in fecal samples obtained from horses. Samples obtained from sheep, cows, dogs, and pigs contained 0.1 to 0.5% cellobiose-positive E. coli. Neither the previously identified cel genes nor the bgl genes from E. coli K-12 were expressed during...
An induced synovitis disease model in ponies. The effects of intra-articular injection of small amounts of E. coli lipopolysaccharide (LPS) into the intercarpal joint of 5 ponies were studied. The LPS induced predictable changes all of which were analogous to acute bacterial infection, except that the development of signs occurred sooner after the LPS injection, and subsided within 36 hours. Fever was monophasic and peaked at 5-7 hours. The ponies exhibited depression, reduced or absent appetite, increased pulse and respiration rates, and lameness. The lameness became evident between 1 and 2 hours after injection, at which time warmth, ar...
Dynamics of the acute uterine response to infection, endotoxin infusion and physical manipulation of the reproductive tract in the mare. The uterine responses after the infusion of saline (PBS), a bacterial suspension, or lipopolysaccharide derived from Escherichia coli, and after stimulation of the reproductive tract were compared. All infusions provoked a response involving both serum proteins and leucocytes. Protein levels peaked within a few hours of infusion, whereas leucocyte concentration peaked later at around 6 h. Bacterial recovery from the uterus followed a similar pattern, with recovery falling dramatically by 12 h. In mares known to be susceptible to infection large numbers of bacteria were again recovered after 24...
Endotoxin-induced hemodynamic and prostaglandin changes in ponies: effects of flunixin meglumine, dexamethasone, and prednisolone. Shock was induced in four groups of anesthetized ponies with an intravenous injection of Escherichia coli endotoxin [125 micrograms/kg]. Five minutes after endotoxin injection, the ponies were given no treatment (group A), flunixin meglumine (FM:1.1 mg/kg) (group B), dexamethasone (2 mg/kg) (group C), or prednisolone (10 mg/kg) (group D). Additionally, FM was given every 3 hours, and the steroids were given at 3, 9, and 24 hours following endotoxin. Hemodynamic measurements were made during the 4-hour anesthetic period. Blood samples were collected for the analysis of prostaglandins, blood che...
Influence of vitamin E and selenium supplement on antibody production in horses. Fifteen horses used for serum production were maintained on low vitamin E and selenium diets. They were divided into four groups receiving: Group 1 no supplements, Group 2 vitamin E, Group 3 selenium and Group 4 both vitamin E and selenium. The humoral immune response to novel antigens, such as tetanus toxoid and equine influenza virus, was increased in groups receiving either vitamin E or selenium/vitamin E. No effects were recorded on the titres against Escherichia coli or the levels of immunoglobulin G.
Molecular cloning and expression in Escherichia coli of equine type I interferons. Using human interferon-alpha 2 (IFN-alpha 2) and IFN-beta DNA to probe an equine genomic library we isolated recombinant phages containing genes for equine interferon-alpha (EqIFN-alpha), interferon-beta (EqIFN-beta), and interferon-omega (EqIFN-omega). Sequence and hybridization analyses of these genes reveal that the equine genome contains gene families of each of these three type I interferon classes. The mature proteins of EqIFN-alpha are 71-77% homologous to human IFN-alpha polypeptides, and, when expressed in E. coli, possess antiviral activity on both equine and human cells. By contrast...
Isolation of piliated Escherichia coli from diarrheic foals. Escherichia coli was isolated from the feces and intestines of foals with and without diarrhea. Piliation of isolates was demonstrated by electron microscopy and agglutination in antisera having specificity for K88, K99, P987 and F41 pili. Piliation was also demonstrated by electron microscopy on organisms which did not react with any of the antisera.
Nosocomial infections and bacterial antibiotic resistance in a university equine hospital. A base-line study of bacteria isolated from horses admitted to the Veterinary Medical Teaching Hospital during a 6-month period was performed to determine the extent of multiresistant nosocomial infections caused by gram-negative aerobic bacteria other than Salmonella spp. Results of this study indicated that 21.9% of the 105 horses from which cultures and sensitivities were available had developed nosocomial gram-negative aerobic infections, with high rates of resistance to gentamicin, kanamycin, and trimethoprim sulfadiazine, three of the most often prescribed antibiotics in this hospital. I...
Endotoxemia in horses: protection provided by antiserum to core lipopolysaccharide. An equine antiserum to core lipopolysaccharide was produced by inoculation of 6 horses with a boiled cell bacterin made from the J-5 mutant of Escherichia coli O111:B4. The antiserum immunoglobulin G titer to J-5 mutant E coli, as determined by enzyme-linked immunosorbent assay, was 1:15,006. Pooled serum prepared before inoculation (preimmune serum) had a J-5 immunoglobulin G titer of 1:350. The J-5 antiserum was tested for its protective efficacy in sublethal endotoxemia in 14 horses. Four horses served as nontreated controls and were given nothing before endotoxin challenge exposure (10 mic...
[Etiology and chemotherapy of suppurative surgical infection in horses and cattle]. A total of 24 horses and 42 cattle with a variety of local suppurative processes (wounds, abscesses, phlegmons, tendovaginitis, etc.) were studied under conditions of the clinic with regard to the most commonly found microbial species and the opportunity to work out antibioticogrammes in terms of the effectiveness of 11 of the chemotherapeutic agents widely used in the practice. It was found that prevailing in horses were staphylococci and streptococci. In cattle Corynebacterium pyogenes was predominantly established. Besides, there was a rising trend in the part played by representative agent...
Modulation of arachidonic acid metabolism in endotoxic horses: comparison of flunixin meglumine, phenylbutazone, and a selective thromboxane synthetase inhibitor. Two cyclooxygenase inhibitors (flunixin meglumine and phenylbutazone) and a selective thromboxane synthetase inhibitor were assessed in the management of experimental equine endotoxemia. Drugs or saline solution were administered to 16 horses 15 minutes before administration of a sublethal dose of endotoxin (Escherichia coli 055:B5). Plasma concentrations of thromboxane B2 (TxB2), prostacyclin (6-keto PGF1 alpha), plasma lactate, and hematologic values and clinical appearance were monitored for 3 hours after endotoxin administration. Pretreatment with flunixin meglumine (1 mg/kg of body weight...
Effects of endotoxin on lung water, hemodynamics, and gas exchange in anesthetized ponies. Effects of endotoxemia on lung water, hemodynamics, and gas exchange were determined in ponies breathing a mixture of halothane and 100% O2. Escherichia coli endotoxin was infused IV at 20 micrograms/kg of body weight for 1 hour followed by 10 micrograms/kg/hr the subsequent 4 hours. By 0.25 hour, endotoxin increased mean pulmonary artery pressure and pulmonary vascular resistance; this was followed by a return to base-line values by 0.5 and 1 hour, respectively. A 2nd increase in pulmonary vascular resistance occurred by 5 hours of endotoxemia. During the last 2 hours of endotoxin infusion, c...
Effects of flunixin meglumine on cardiopulmonary responses to endotoxin in ponies. The effects of endotoxemia on cardiopulmonary parameters, before and after cyclooxygenase blockade, were determined in anesthetized ponies spontaneously breathing a mixture of halothane and 100% O2. Escherichia coli endotoxin was infused intravenously at 20 micrograms/kg for 1 h followed by 10 micrograms X kg-1 X h-1 the subsequent 4 h. By 15 min endotoxin increased mean pulmonary arterial pressure (Ppa), pulmonary vascular resistance (PVR), and alveolar dead space ventilation (VDA/VT), and these were followed by a return to base-line values by 30 min. A second increase in PVR occurred by 5 h ...
Effect of intrauterine infusion of Escherichia coli endotoxin in postpartum pony mares. Fifteen pony mares were assigned to 1 of 3 treatment groups after foaling: Group 1, 35 ml of sterile saline solution was infused into the uterine lumen within 24 hours after parturition (6 mares); group 2, 300 mg of Escherichia coli endotoxin was infused into the uterine lumen within 24 hours after parturition (6 mares); and group 3, 300 mg of E coli endotoxin was infused into the uterine lumen between 72 and 96 hours after parturition (3 mares). Rectal temperatures were taken at -1, -0.5, 0, 0.5, 1, 1.5, 2, 3, 4, and 5 hours after treatment. Venous blood samples were also taken at these times...
Cefadroxil in the horse: pharmacokinetics and in vitro antibacterial activity. Sodium cefadroxil was administered as a single intravenous dose (25 mg/kg) to six healthy adult mares. Plasma samples were collected over a 24-h period and cefadroxil concentrations were measured by microbiological assay. The pharmacokinetic behavior of the drug was appropriately described in terms of a one-compartment open model. Values for the major pharmacokinetic terms were: extrapolated initial plasma concentration = 59.2 +/- 15.0 micrograms/ml; half-life = 46 +/- 20 min; apparent volume of distribution = 462 +/- 191 ml/kg; and body clearance = 7.0 +/- 0.6 ml/min.kg. In a subsequent study...
Effects of flunixin meglumine on blood pressure and fluid compartment volume changes in ponies given endotoxin. A study was conducted to determine whether body fluids undergo a net shift from one compartment to another during endotoxin-induced shock in the pony, and whether flunixin meglumine alters these endotoxin-induced changes in the volumes of body fluid compartments. Total blood, RBC, and plasma volumes were determined, using 51Cr-labeled RBC and PCV that were corrected for trapped plasma. Total body water was measured by distribution of 3HOH. Arterial blood pressure was measured directly, using a blood pressure transducer. Treatment (flunixin meglumine, 1.1 mg/kg of body weight) was given to 6 of...
Effect of endotoxin administration on body fluid compartments in the horse. Plasma volume, extracellular fluid volume (ECFV), and total body water (TBW) were measured before and after endotoxin (Escherichia coli) administration in 6 conscious adult horses. Evan's blue dye, sodium thiocyanate, and antipyrine were the test substances used to estimate plasma volume, ECFV, and TBW, respectively. Pharmacokinetic analysis of plasma concentration vs time was used to determine changes in body fluid compartments. The pathophysiologic effects of endotoxin were monitored by clinical evaluation, blood chemical changes, and blood gas determinations. All horses became dyspneic with...
Effects of intrauterine infusion of Escherichia coli endotoxin in anestrous and steroid treated pony mares. This study was conducted to determine if Escherichia coli endotoxin was absorbed from the equine uterus and if exogenous progesterone and estrogen affected the absorption of intrauterine endotoxin. Six mature anestrous pony mares were used in three consecutive crossover experiments (Periods) with a 14 day recovery between each period. Mares were randomly assigned to one of two treatment groups (three mares per group) and received an intrauterine infusion of either saline or endotoxin. Treatment groups were reversed and readministered after 14 days completing a crossover design (Period 1). Duri...
Flunixin meglumine attenuation of endotoxin-induced damage to the cardiopulmonary vascular endothelium of the pony. Endotoxic shock was induced in 5 ponies by intraperitoneal injections of 20, 40, 60, 80, and 80 micrograms of Escherichia coli endotoxin (LPS)/kg of body weight at 0, 6, 12, 18, and 24 hours, respectively. At 24 hours, the ponies also were given 20 micrograms of LPS/kg via catheter in the left ventricle of the heart. A 2nd group of 4 ponies was given 1.1 mg of flunixin meglumine (FM)/kg, IV, at 6, 12, 18, and 24 hours just before the corresponding LPS injection. Two hours after the 24-hour LPS injection, the ponies in both groups were anesthetized, the lungs were perfused with fixative, and po...
Selection of an aminoglycoside antibiotic for administration to horses. The serum concentrations of the aminoglycosides neomycin, kanamycin and streptomycin were determined after intravenous (iv) and intramuscular (im) administration. These values were then related to the minimum inhibitory concentrations (MIC) of a number of equine pathogenic bacteria to determine the duration of therapeutic serum concentrations of the aminoglycosides in the horse. Pharmacokinetic analysis of the data using neomycin as the example revealed a mean (+/- sd) peak serum concentration of 23.2 +/- 10.2 micrograms/ml present at 30 mins, and at 8 h the serum concentration was 2.8 +/- 0.8...
Endotoxin-induced hematologic and blood chemical changes in ponies: effects of flunixin meglumine, dexamethasone, and prednisolone. To evaluate the effect of certain drugs on hematologic changes, blood chemical values, and survival in endotoxin shock, anesthetized ponies were given (IV) endotoxin (Escherichia coli O55:B5) and then treated as follows: Group A ponies--given a saline infusion at 5 minutes and at 3 hours after they were given endotoxin; group B ponies--given flunixin meglumine at 5 minutes and at 3, 6, 9, and 24 hours after they were given endotoxin; group C ponies--treated with dexamethasone; and group D ponies--treated with prednisolone at 5 minutes and at 3, 9, and 24 hours after they were given endotoxin. ...
Isolation and structural characterization of the equine erythrocyte receptor for enterotoxigenic Escherichia coli K99 fimbrial adhesin. The erythrocyte receptor for Escherichia coli K99 fimbrial adhesin was isolated from equine erythrocytes and characterized as Neu5Gc-alpha(2----3)-Galp-beta(1----4)-GLcp-beta(1----1)-Ceramide. This glycolipid acted as the receptor for K99 by four different experimental approaches: inhibition of equine erythrocyte hemagglutination by preincubation of K99-positive bacteria or purified K99 fimbriae with the isolated glycolipid; inhibition of attachment of K99-positive bacteria to porcine intestinal epithelial cells in the presence of the isolated glycolipid; induction of binding of K99-positive b...
Pathomorphology and pathogenesis of bacterial meningoventriculitis of neonatal ungulates. Bacterial meningoventriculitis was studied in 26 neonatal ungulates. Preceded by a substantial bacteremia, usually due to Escherichia coli, the fibrinopurulent inflammation involved leptomeninges, choroid plexuses, and ventricle walls, but largely spared the neuraxial parenchyma. It is proposed that this surface-relatedness results from the transport of bacteria by monocytes of low bactericidal power, migrating by normal pathways to maintain significant surface populations of macrophages. The neuraxial parenchyma is spared because of its normal lack of a macrophage population. A similar pathog...
Attachment of E. coli-bearing K88 antigen to equine brush-border membranes. Equine small intestinal brush-border membranes, from 40 adult horses were tested in vitro for the presence of receptors for the Escherichia coli adhesive antigens K88ab, K88ac and K99. Only K88-positive strains of E. coli adhered strongly to horse brush-border membranes. In contrast, a K88-negative mutant strain J2, 2 K99-positive strains and 3 E. coli strains isolated from foals failed to adhere to horse brush-border membranes. Purified K88ac pili when reacted with equine brush-border membranes inhibited to a great extent the adhesion of K88-positive E. coli. Similarly, K88-positive E. coli p...
