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.
Serum interleukin-6 concentrations in endotoxin-infused neonatal foals. Serum interleukin-6 (IL-6) concentration was measured in 11 colostrum-fed (CF) and 8 colostrum-deprived (CD) 2- to 3-day-old foals after foals were infused with lipopolysaccharide (LPS; Escherichia coli O55:B5 endotoxin, 0.5 microgram/kg of body weight in sterile saline [0.9% NaCl] solution). Four CF and 2 CD foals were given saline solution alone. Serum IL-6 concentration was estimated by use of an in vitro proliferative bioassay, using the IL-6 dependent B.13.29 clone 9 cells. Interleukin-6 concentration increased in all LPS-infused foals, and geometric mean serum IL-6 concentration was sign...
Bronchointerstitial pneumonia and respiratory distress in young horses: clinical, clinicopathologic, radiographic, and pathological findings in 23 cases (1984-1989). Twenty-three foals, between 1 and 7 months old, with signs of acute respiratory distress, were examined at the Veterinary Medical Teaching Hospital (VMTH), University of California, Davis, between 1984 and 1989. Characteristic features included sudden onset of severe respiratory distress and tachypnea, cyanosis unresponsive to nasal oxygen, pyrexia, hypoxemia, hypercapneic respiratory acidosis, poor response to treatment, and histopathologic lesions of bronchiolitis and bronchointerstitial pneumonia. Seven of the 23 foals were normal before the onset of respiratory distress, 3 foals were found...
Cloning, expression and characterization of horse L-ferritin in Escherichia coli. Horse L-ferritin cDNA was cloned from horse liver, and the base sequence was determined. The L-ferritin was expressed using pTZ18U encoding lac promoter, and found to possess an additional 8-amino acid sequence at the N-terminus as compared with commercially obtained horse spleen (natural) ferritin. It was determined that there was Pro at position 94 in both the recombinant and natural L-ferritin, although it was previously reported that Leu was in this position in the natural species. Transmission electron microscopy showed that this recombinant ferritin formed a 24-mer shell.
Molecular cloning and expression of an intracellular serpin: an elastase inhibitor from horse leucocytes. Horse blood leucocytes contain an elastase inhibitor (HLEI) belonging to the serpin family. Poly(A)+RNA isolated from these cells was used to construct a cDNA library in lambda gt10, which was first screened with a synthetic degenerate oligonucleotide probe corresponding to the amino acid sequence of the reactive centre of the inhibitor. Three clones were obtained covering the entire coding region of the protein. Sequencing of these clones showed identity with the amino acid sequence obtained from Edman degradation of the elastase inhibitor. The coding sequence of the HLEI cDNA was cloned into...
Linkage of serum resistance, aerobactin production, and resistance to antimicrobial agents on conjugal plasmids in some strains of Escherichia coli isolated from septic foals. Fifteen isolates of Escherichia coli obtained from the blood and tissues of septic foals had plasmid DNA of size ranging from 2.5 to 93 megadaltons. These isolates grew in normal equine serum (serum resistant), a trait previously documented to be expressed by isolates obtained from blood and tissues of septic foals, but not by isolates obtained from the feces of clinically normal horses. Of these isolates, 3 contained conjugal plasmids that encoded resistance to multiple antimicrobial agents linked to serum resistance and, in 1 isolate, to production of aerobactin as well. Serum resistance and...
A prospective study of septicaemia in colostrum-deprived foals. Fourteen mares and their foals were attended at parturition. After mare-foal bonding, 8 colostrum-deprived (CD) foals were removed from their dams, deprived of colostrum, and provided with an alternative milk source for the first 24 h of life. The mares were milked out every 2-4 h during this period to remove colostrum, after which the CD foals were returned to their mares and allowed to nurse. Six colostrum-fed (CF) foals were allowed to suck colostrum in the normal manner. Foal serum IgG concentration was determined by single radial immunodiffusion (means, CD = 0 mg/dl; CF = 1,508 mg/dl). Ac...
Isolation and characterization of four basic proteins from horse eosinophilic granules. Four new basic proteins were isolated from horse eosinophils and purified. The eosinophils release these proteins after permeabilization with saponin and degranulation stimulized by guanosine 5'-O-thiotriphosphate. The proteins were separated and purified on a Superose P12- and a Mono S-column by fast protein liquid chromatography. The amino acid composition, the relative molecular mass, the isoelectric point and the partial N-terminal sequence of the four proteins were determined. Papain-activation and ribonuclease activity of the four proteins were tested for comparison with the human eosino...
Effects of intra-articularly administered endotoxin on clinical signs of disease and synovial fluid tumor necrosis factor, interleukin 6, and prostaglandin E2 values in horses. In each of 4 horses, sterile synovitis was induced by intra-articular injection of 3 micrograms of Escherichia coli endotoxin (lipopolysaccharide, LPS) into one antebrachiocarpal joint; an equal volume (2 ml) of phosphate-buffered saline solution (PBSS) was injected into the opposite, control carpus. Blood and 1.5 ml of synovial fluid were obtained at postinjection hours (PIH) 0, 2, 4, 8, 12, 18, 42, 66, and 144. Synovial fluid sample collection was accomplished by use of an indwelling, intra-articular catheter through PIH 12, and by arthrocentesis subsequently. Joint fluid samples were analyz...
Characteristics of Escherichia coli isolated from septic foals. Fifteen Escherichia coli isolates from the blood and tissue of foals with septicemia were compared with 15 from the feces of clinically normal horses. Comparisons were made with respect to survival in normal equine serum, production of aerobactin, and production of hemolysin. Isolates from the blood and tissues of septic foals were more likely to be resistant to equine serum than were isolates from feces of clinically normal horses. There were minimal differences between the isolates with respect to aerobactin and hemolysin production, almost all being nonhemolytic and aerobactin negative. Ser...
Antibody to a recombinant merozoite protein epitope identifies horses infected with Babesia equi. Horses infected with Babesia equi were previously identified by the presence of antibodies reactive with a merozoite surface protein epitope (D. P. Knowles, Jr., L. E. Perryman, L. S. Kappmeyer, and S. G. Hennager. J. Clin. Microbiol. 29:2056-2058, 1991). The antibodies were detected in a competitive inhibition enzyme-linked immunosorbent assay (CI ELISA) by using monoclonal antibody 36/133.97, which defines a protein epitope on the merozoite surface. The gene encoding this B. equi merozoite epitope was cloned and expressed in Escherichia coli. The recombinant merozoite protein, designated equ...
Equine tumor necrosis factor alpha: cloning and expression in Escherichia coli, generation of monoclonal antibodies, and development of a sensitive enzyme-linked immunosorbent assay. We describe the production and purification of recombinant equine tumor necrosis factor alpha (rETNF alpha), generation and characterization of murine monoclonal antibodies (Mabs) and rabbit polyclonal antibodies (Pabs) against ETNF alpha, and development of a sensitive enzyme-linked immunosorbent assay (ELISA). Genomic-derived DNA sequences encoding mature ETNF alpha were reconstructed by the polymerase chain reaction (PCR) and oligonucleotide-directed mutagenesis and were cloned into the vector pFLAG-1 for expression in Escherichia coli. rETNF alpha was purified by anti-FLAG immunoaffinity c...
Evaluation of progesterone treatment to create a model for equine endometritis. To investigate a model for equine endometritis, 12 mares with normal reproductive tracts were divided into 2 groups. All mares received progesterone in oil, 250 mg im, daily. At 5 days after initiation of progesterone administration, the uteri were inoculated with 10(6) colony forming units of Pseudomonas aeruginosa. The day of inoculation was designated Day 0. On Day 6, endometrial swab samples yielded P. aeruginosa in 5 mares; samples from the other 7 mares yielded heavy growth of Escherichia coli, Streptococcus zooepidemicus, Klebsiella pneumoniae, Enterobacter spp., Citrobacter diversus, S...
Streptomycin-resistant Escherichia coli as a marker of vulvovestibular contamination of endometrial culture swabs in the mare. To investigate the vulvovestibular contamination of endometrial culture swabs in the mare, a liquid culture of a streptomycin-resistant strain of Escherichia coli was applied to the vulvovestibular area of mares and used as a marker of contamination of endometrial culture swabs. Prior to taking endometrial swabs, the perineal area was washed with soap, rinsed with water, and dried. Endometrial culture swabs were taken from mares that were in anestrus or diestrus and from mares that were in estrus. When a manual transvaginal swabbing technique was used, 22 of 24 endometrial swab specimens from ...
Identification of eNAP-1, an antimicrobial peptide from equine neutrophils. Endogenous, cysteine-rich antimicrobial peptides known as defensins are prominent components of human, rabbit, and rat neutrophils, yet little is known about their occurrence in other mammalian species. Although we did not detect mature (i.e., processed) defensins in equine neutrophil granules, we found that these granules contained small amounts of other cysteine-rich peptides with antimicrobial activity. One of these, eNAP-1, was purified by a combination of gel permeation and reversed-phase high-performance liquid chromatography from acid extracts prepared from the cytoplasmic granules of e...
Septic peritonitis associated with caudal myotomy in a Tennessee walking horse. A 2-year-old Tennessee Walking Horse colt was admitted for evaluation of signs of abdominal pain, inappetence, and constipation of 5 days' duration. Two days prior to the onset of signs, the owner had cut the sacrococcygeal muscles as part of a tail-setting procedure. On examination, the horse was febrile and lethargic, and intestinal sounds were not heard on auscultation. Results of peritoneal fluid analysis were indicative of peritonitis. The horse continued to deteriorate and died despite treatment with antimicrobials, flunixin meglumine, and balanced electrolyte solution. At necropsy, the ...
Endotoxin-induced production of interleukin 6 by equine peritoneal macrophages in vitro. A study was performed to determine whether equine peritoneal macrophages produce interleukin 6 (IL-6) in vitro in response to endotoxin. Peritoneal fluid was collected from 14 clinically normal adult horses and was used as the source of peritoneal macrophages. Macrophages from each horse were isolated and cultured separately in vitro in the absence or presence of various concentrations (0.5, 5, 500 ng/ml) of endotoxin (lipopolysaccharide from Escherichia coli 055:B5). Culture medium supernatants were collected after 3, 6, 12, and 24 hours' incubation and were frozen at -70 C until assayed for ...
Septic cholangitis and peritonitis in a gelding. An 8-year-old Arabian gelding with septic cholangitis and peritonitis was successfully treated with trimethoprim/sulfadiazine. The gelding was referred for evaluation of signs of abdominal pain, icterus, fever, and weight loss. Peritoneal fluid analysis revealed septic and suppurative peritonitis. Culture of the peritoneal fluid yielded Escherichia coli and Klebsiella pneumoniae, which were sensitive to trimethoprim/sulfadiazine. On the basis of results of hepatic ultrasonography, a diagnosis of septic cholangitis also was made. The horse was treated with 30 mg of trimethoprim/sulfadiazine/kg,...
The spectrum of antibiotic resistance in human and veterinary isolates of Escherichia coli collected from 1984-86 in northern India. This study was undertaken to assess the spectrum of drug resistance prevalent in Escherichia coli isolates from human and animal populations in Northern India. Three hundred and two isolates of Escherichia coli isolated from various infections of humans (47 from diarrhoea; 101 from urinary tract infection) and veterinary animals (17 from poultry septicaemia; 75 from bovine diarrhoea; 14 from ovine diarrhoea and 48 from equine metritis) were studied for their susceptibility to ampicillin, cephaloridine, amoxycillin, cloxacillin, oxytetracycline, doxycycline, chloramphenicol, gentamicin, and tri...
The prevalence of enteric pathogens in diarrhoeic thoroughbred foals in Britain and Ireland. A survey of 77 normal and 326 diarrhoeic foals in Britain and Ireland from 1987 to 1989 revealed a significantly higher prevalence of Group A rotaviruses and Aeromonas hydrophila in diarrhoeic foals. The prevalence of cryptosporidia, potentially pathogenic Escherichia coli, Yersinia enterocolitica and Clostridium perfringens was similar in normal or diarrhoeic foals. Rotaviruses had a similar prevalence in all age groups of scouring foals up to three months of age, with an overall prevalence of 37 per cent among diarrhoeic foals. The number of cases of diarrhoea varied considerably from year t...
Clinical chemical constituents in relation to liver amyloidosis in serum-producing horses. Serum activities of gamma-glutamyl transferase (GGT), alkaline phosphatase (AP), aspartate aminotransferase (AST), and concentrations of total bilirubin and total bile acids were screened during a 5 year period in 27 horses used for production of hyperimmune serum. The horses investigated were regularly immunized with live cultures of the endotoxin-releasing bacteria Escherichia coli or Pasteurella multocida, the individual animals having undergone such treatment for periods varying from 2 weeks to 10 years. In a majority of the horses, GGT-activity had increased within 6 to 7 years of first h...
Expression in Escherichia coli of a synthetic gene coding for horse heart myoglobin. A gene for expression of horse heart myoglobin in Escherichia coli has been constructed in one step from long synthetic oligonucleotides. The synthetic gene contains an efficient translation initiation signal and used codons that are commonly found in E. coli. Unique restriction sites are placed throughout the gene. It has been inserted in a phagemid vector and is expressed from the lac promoter in E. coli at high efficiency, the soluble heme protein representing approximately 10% of soluble protein. Two versions of horse heart myoglobin were produced with aspartic acid or asparagine at residu...
Aerobic bacterial isolates in horses in a university hospital, 1986-1988. Bacterial isolations were reviewed from equine trachea, guttural pouch, uterus, wounds, abscesses, blood, synovial fluid, and abdominal fluid submitted to the Clinical Bacteriology Laboratory of the School of Veterinary Medicine at the University of Montreal for aerobic bacterial culture from 1986 to 1988. Of the 733 samples submitted, 324 (44%) were positive for bacterial growth, and 233 antimicrobial sensitivity tests were performed. Seventy-six percent of all positive samples yielded one bacterial species and two were isolated from 22% of positive samples. Streptococcus zooepidemicus, Esche...
Influence of an omega-3 fatty acid-enriched ration on in vivo responses of horses to endotoxin. Because certain inflammatory processes are dependent on the fatty acid composition of the cellular membrane, dietary manipulations that replace omega-6 fatty acids with omega-3 fatty acids may modify inflammatory responses. We investigated the effect of supplemental dietary linseed oil, containing the omega-3 fatty acid, alpha-linolenic acid, on in vivo responses of horses to endotoxin. One group of horses (n = 6) was fed a control pelleted ration (0% linseed oil), and another group of horses (n = 6) was fed an 8% linseed oil pelleted ration. After 8 weeks of consuming these rations, all horse...
Cloning the cDNA for horse growth hormone and expression in Escherichia coli. A 514 bp cDNA transcript coding for 78% of horse (Equus caballus.) GH has been cloned and sequenced. The deduced amino acid sequence corresponded precisely to that previously obtained by protein sequencing and, in addition, provided new sequence information for the signal peptide. The missing 3' fragment of the cDNA was reconstructed using synthetic oligonucleotides and site-specific directed mutagenesis. The complete cDNA sequence was then inserted into an expression vector (PIN-III-lppp-5) which utilizes a bacterial signal peptide to secrete the expressed product into the periplasmic space o...
Effects of an infusion of dopamine on the cardiopulmonary effects of Escherichia coli endotoxin in anaesthetised horses. Horses with colic may be endotoxaemic and subsequently develop hypotension during anaesthesia for surgical operation. The aim of this study was to evaluate the efficacy of dopamine as a means to improve cardiovascular function in anaesthetised endotoxaemic horses. Nine horses (five in group 1 and four in group 2) were anaesthetised with thiopentone and guaifenesin and anaesthesia was maintained with halothane. After approximately one hour, facial artery pressure, heart rate, pulmonary artery pressure, cardiac output, temperature, pHa, PaCO2, PaO2, base excess, packed cell volume, plasma protei...
Correlation of clinical and laboratory data with serum tumor necrosis factor activity in horses with experimentally induced endotoxemia. Serum tumor necrosis factor (TNF) activity was quantitated in 8 horses given an IV infusion of endotoxin (0.03 micrograms of lipopolysaccharide/kg of body weight, from Escherichia coli 055:B5) in 0.9% NaCl solution over 1 hour. Serum TNF activity was likewise measured in 6 horses given only 0.9% sterile NaCl solution at the same rate. The duration of serum TNF activity was determined, and serum TNF activity was correlated with clinical and laboratory changes during the induced endotoxemia. Horses had no serum TNF activity prior to endotoxin administration, but geometric mean serum TNF activity...
The open reading frame ORF S3 of equine infectious anemia virus is expressed during the viral life cycle. The genome of equine infectious anemia virus (EIAV) contains several small open reading frames (ORFs), the importance of which in the development of the virus is not clear. We investigated the possibility that the largest of these ORFs (ORF S3) is expressed during the course of the viral infection. The ORF S3 information was expressed in Escherichia coli, and the antigen was used to raise monospecific antiserum. A 20-kDa protein expressed in cells producing EIAV was identified as the gene product of ORF S3. Furthermore, sera from EIAV-infected animals specifically recognized this protein, indi...
Effect of dietary alpha-linolenic acid on equine monocyte procoagulant activity and eicosanoid synthesis. To investigate the effects of an omega-3 fatty acid-enriched ration on the in vitro response of equine monocytes to endotoxin, an 8-week feeding trial was conducted in which linseed oil served as the source of the omega-3 fatty acid, alpha-linolenic acid. One group of horses was fed a control pelleted ration and the other group was fed an 8% linseed oil-enriched pelleted ration. After 8 weeks of feeding, monocytes were isolated and incubated in the presence of Escherichia coli O55:B5 endotoxin for 6 hr. After 8 weeks on the rations, the mean procoagulant activity and thromboxane B2 production ...
Septicemia, atrial fibrillation, cardiomegaly, left atrial mass, and Rhodococcus equi septic osteoarthritis in a foal. A foal with vegetative bacterial endocarditis affecting the wall of the left atrium was treated successfully with cefotaxime, erythromycin, and rifampin. Bacterial isolates included Escherichia coli from blood and Rhodococcus equi from a P-type osteomyelitic lesion of the left third metatarsal bone and from synovial fluid from the left metatarsophalangeal joint. Cardiac complications included cardiomegaly and atrial fibrillation, which responded to treatment with digoxin and quinidine sulfate. Cardiac function was considered normal 18 months after treatment. Bacteriologic cure of osteoarthriti...
Synovial fluid pH, cytologic characteristics, and gentamicin concentration after intra-articular administration of the drug in an experimental model of infectious arthritis in horses. Chemical and cytologic effects and bactericidal activity of gentamicin in septic synovial fluid were evaluated in an experimental model of infectious arthritis in horses. Septic arthritis was induced by inoculation of approximately 7.5 X 10(6) colony-forming units of Escherichia coli into 1 antebrachiocarpal joint in each of 16 clinically normal adult horses. Clinical signs of septic arthritis were evident 24 hours after inoculation. Horses were allotted to 3 groups: group-1 horses (n = 5) each were given 150 mg of gentamicin (50 mg/ml; 3 ml) intra-articularly (IA); group-2 horses (n = 5) each...