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Gomez DE, Rodriguez-Lecompte JC, Lofstedt J, Arroyo LG, Nino-Fong R, McClure JT. Detection of endotoxin in plasma of hospitalized diarrheic calves. J Vet Emerg Crit Care (San Antonio) 2019; 29:166-172. [PMID: 30810269 DOI: 10.1111/vec.12815] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/06/2016] [Accepted: 01/14/2017] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To investigate whether lipopolysaccharide (LPS) is present in plasma of calves with naturally occurring diarrhea. The second objective was to determine whether plasma [LPS] correlates with clinical, hematological, biochemical, and acid-base variables, and whether [LPS] differs between surviving and nonsurviving diarrheic calves. DESIGN Prospective observational study (January 2012-May 2014). SETTING Veterinary teaching hospital. ANIMALS Thirty-four calves <28 days old admitted for diagnosis and treatment of diarrhea and 30 healthy control calves. MEASUREMENTS AND MAIN RESULTS Admission demographics, physical examination, blood gas, biochemistry analysis, and outcome data were recorded. Plasma concentration of LPS was determined using a bovine LPS ELISA assay. Plasma [LPS] was detected in both healthy and diarrheic calves. Plasma [LPS] was significantly higher in diarrheic than healthy calves (median: 0.99 ng/mL; Interquartile range (IQR): 0.068, vs 0.88 ng/mL; 0.065 ng/mL, respectively; P < 0.001). Plasma [LPS] was higher in nonsurviving (1.04 ng/mL; 0.07 ng/mL) than in surviving calves (0.98 ng/mL; 0.022 ng/mL; P < 0.001). Plasma [LPS] was higher in beef (1.07 ng/mL; 0.182 ng/mL) than in dairy diarrheic calves (0.99 ng/mL; 0.022 ng/mL; P < 0.001). In diarrheic calves, plasma [LPS] correlated with [l-lactate] (r2 = 0.496; P = 0.002); hypoglycemia (r2 = -0.453; P = 0.007); increased unmeasured strong ions (r2 = 0.332; P = 0.050), [Mg2+ ] (r2 = 0.475; P = 0.004), and [phosphate] (r2 = 0.468; P = 0.005), and increased aspartate aminotransferase activity (r2 = 0.348; P = 0.003). CONCLUSIONS This study highlights a potential role of LPS in the pathogenesis of metabolic derangements such as hyperlactatemia, hypoglycemia, and increased concentration of unmeasured strong anions in diarrheic calves. Further investigation evaluating the effect of LPS on l-lactate and glucose metabolism in diarrheic calves is warranted.
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Affiliation(s)
- Diego E Gomez
- Department of Health Management Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Juan C Rodriguez-Lecompte
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Jeanne Lofstedt
- Department of Health Management Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Luis G Arroyo
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Rodolfo Nino-Fong
- Department of Biomedical Sciences, Ross University School of Veterinary Medicine, St. Kitts and Nevis
| | - J Trenton McClure
- Department of Health Management Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
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Parkinson NJ, Buechner-Maxwell VA, Witonsky SG, Pleasant RS, Werre SR, Ahmed SA. Characterization of basal and lipopolysaccharide-induced microRNA expression in equine peripheral blood mononuclear cells using Next-Generation Sequencing. PLoS One 2017; 12:e0177664. [PMID: 28552958 PMCID: PMC5446123 DOI: 10.1371/journal.pone.0177664] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 05/01/2017] [Indexed: 02/03/2023] Open
Abstract
The innate immune response to lipopolysaccharide contributes substantially to the morbidity and mortality of gram-negative sepsis. Horses and humans share an exquisite sensitivity to lipopolysaccharide and thus the horse may provide valuable comparative insights into this aspect of the inflammatory response. MicroRNAs, small non-coding RNA molecules acting as post-transcriptional regulators of gene expression, have key roles in toll-like receptor signaling regulation but have not been studied in this context in horses. The central hypothesis of this study was that lipopolysaccharide induces differential microRNA expression in equine peripheral blood mononuclear cells in a manner comparable to humans. Illumina Next Generation Sequencing was used to characterize the basal microRNA transcriptome in isolated peripheral blood mononuclear cells from healthy adult horses, and to evaluate LPS-induced changes in microRNA expression in cells cultured for up to four hours. Selected expression changes were validated using quantitative reverse-transcriptase PCR. Only miR-155 was significantly upregulated by LPS, changing in parallel with supernatant tumor necrosis factor-α concentration. Eight additional microRNAs, including miR-146a and miR-146b, showed significant expression change with time in culture without a clear LPS effect. Target predictions indicated a number of potential immunity-associated targets for miR-155 in the horse, including SOCS1, TAB2 and elements of the PI3K signaling pathway, suggesting that it is likely to influence the acute inflammatory response to LPS. Gene alignment showed extensive conservation of the miR-155 precursor gene and associated promoter regions between horses and humans. The basal and LPS-stimulated microRNA expression pattern characterized here were similar to those described in human leukocytes. As well as providing a resource for further research into the roles of microRNAs in immune responses in horses, this will facilitate inter-species comparative study of the role of microRNAs in the inflammatory cascade during endotoxemia and sepsis.
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Affiliation(s)
- Nicholas J. Parkinson
- Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, Virginia, United States of America
- * E-mail:
| | - Virginia A. Buechner-Maxwell
- Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, Virginia, United States of America
| | - Sharon G. Witonsky
- Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, Virginia, United States of America
| | - R. Scott Pleasant
- Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, Virginia, United States of America
| | - Stephen R. Werre
- Laboratory for Study Design and Statistical Analysis, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, Virginia, United States of America
| | - S. Ansar Ahmed
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, Virginia, United States of America
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Hytychová T, Bezděková B. Retrospective evaluation of blood culture isolates and sepsis survival rate in foals in the Czech Republic: 50 cases (2011-2013). J Vet Emerg Crit Care (San Antonio) 2015. [PMID: 26220509 DOI: 10.1111/vec.12348] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To identify the specific pathogens causing sepsis in hospitalized foals in the Czech Republic and identify important factors associated with their survival. DESIGN A retrospective study from 2011 to 2013. SETTING University veterinary teaching hospital. ANIMALS Fifty compromised foals. INTERVENTIONS None. MEASUREMENT AND MAIN RESULTS Blood was aseptically collected for bacterial culture from compromised foals. The foals were classified as septic according to a positive blood culture result or sepsis score ≥11. Blood cultures were positive in 44% of the foals. In these positive cultures, 27.3% had only Gram-positive (G+) bacteria and 54.5% had only Gram-negative (G-) bacteria. A mixed bacterial population was presented in 18.2% of the positive cultures. Thirty-six foals were classified as septic on the basis of positive blood culture or a sepsis score ≥11. In the group of foals that did not survive, there were significantly more foals with low levels of immunoglobulin G (IgG) than foals with normal levels of IgG (P < 0.0001). We also found a significant difference in the proportion of foals with low levels of IgG and positive blood cultures when compared to negative blood cultures. Twenty-six of the 50 foals were discharged from the hospital. Survival was significantly lower in foals with a diagnosis of sepsis than in foals without sepsis. There was no statistically significant difference between foals that died as a result of infection caused by G- or G+ pathogens. There was no difference in the proportion of survivors that did or did not receive antimicrobials prior to admission. CONCLUSIONS In our study, we confirmed the increasing trend for G+ bacteria in blood cultures but G- still predominate. The percentage of nonsurviving septic foals was high.
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Affiliation(s)
- Tat'ana Hytychová
- Equine Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
| | - Barbora Bezděková
- Equine Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
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Wong DM, Sponseller BA, Alcott CJ, Agbedanu PN, Wang C, Hsu WH. Effects of intravenous administration of polymyxin B in neonatal foals with experimental endotoxemia. J Am Vet Med Assoc 2013; 243:874-81. [DOI: 10.2460/javma.243.6.874] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Barton MH, Parviainen A, Norton N. Polymyxin B protects horses against induced endotoxaemia in vivo. Equine Vet J 2010; 36:397-401. [PMID: 15253079 DOI: 10.2746/0425164044868350] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY A safe, affordable and effective treatment for endotoxaemia in horses is needed in order to reduce the incidence of this potentially fatal condition. OBJECTIVE To evaluate the effect of polymyxin B (PMB) on signs of experimentally-induced endotoxaemia. HYPOTHESIS PMB ameliorates the adverse effects of endotoxaemia without causing nephrotoxicity. METHODS Four groups of 6 healthy mature horses each received 20 ng endotoxin/kg bwt i.v. over 30 mins. Additionally, each group received one of the following i.v.; 5000 u PMB/kg bwt 30 mins before endotoxin infusion; 5000 u PMB/kg bwt 30 mins after endotoxin infusion; 1000 u PMB/kg bwt 30 mins prior to endotoxin infusion; or saline. Clinical response data and samples were collected to determine neutrophil count, serum tumour necrosis factor (TNF) activity, plasma thromboxane B2 concentration and urine gamma glutamyltranspeptidase (GGT) to creatinine ratio. RESULTS Treatment with PMB before or after administration of endotoxin significantly reduced fever, tachycardia and serum TNF, compared to horses receiving saline. The differences in response to endotoxin were greatest between horses that received saline vs. those that received 5000 u PMB/kg bwt prior to endotoxin. Urine GGT:creatinine did not change significantly. CONCLUSIONS AND POTENTIAL RELEVANCE This study indicates that PMB may be a safe and effective treatment of endotoxaemia, even when administered after onset. Although nephrotoxicity was not demonstrated with this model, caution should be exercised when using PMB in azotaemic patients.
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Affiliation(s)
- M H Barton
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, USA
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Atherton RP, Furr M. Endotoxin release after antimicrobial treatment in sick foals is mediated by antimicrobial class. J Equine Vet Sci 2006. [DOI: 10.1016/j.jevs.2006.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Werners AH, Bull S, Fink-Gremmels J. Endotoxaemia: a review with implications for the horse. Equine Vet J 2005; 37:371-83. [PMID: 16028631 DOI: 10.2746/0425164054529418] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- A H Werners
- Department of Veterinary Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 16, 3584 CM Utrecht, The Netherlands
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Peek SF, Borah S, Semrad S, McGuirk S, Slack JA, Patton E, Coombs D, Lien L, Darien BJ. Plasma endotoxin concentration in horses: a methods study. Vet Clin Pathol 2004; 33:29-31. [PMID: 15048624 DOI: 10.1111/j.1939-165x.2004.tb00346.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Accurate determination of plasma endotoxin concentration is critical for ex vivo and in vitro cellular and molecular studies of endotoxemia in horses. However, reports are conflicting with respect to anticoagulant, handling, and sample preparation. OBJECTIVE The purpose of this study was to determine the effect of blood sample fraction and handling time on measurement of endotoxin concentration in horses. METHODS Whole blood, anticoagulated with 3.8% (0.12 M) sodium citrate (9:1), was collected from 5 healthy horses. Whole blood (WB), platelet-rich plasma (PRP), and platelet-poor plasma (PPP) were spiked with endotoxin (2 EU/mL). Endotoxin-spiked WB samples were centrifuged immediately to generate PRP for measurement. Endotoxin concentration was subsequently measured by Limulus amebocyte assay at 0, 15, 30, 45, and 60 minutes. Assays were performed in triplicate and results were analyzed using Student's t-test, with significance set at P <.05. RESULTS Mean endotoxin concentrations in 2 EU/mL-spiked WB were significantly different from those in PPP at all time points tested. Recovery of endotoxin in PRP generated from WB was significantly diminished after just 15 minutes. CONCLUSION PRP generated from WB is significantly more reliable than PPP in determining endotoxin concentration ex vivo. Measurement of endotoxin in PRP generated from WB was significantly diminished after 15 min, identifying a time frame within which to process blood samples for endotoxin analysis.
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Affiliation(s)
- Simon F Peek
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA
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Bentley AP, Barton MH, Lee MD, Norton NA, Moore JN. Antimicrobial-induced endotoxin and cytokine activity in an in vitro model of septicemia in foals. Am J Vet Res 2002; 63:660-8. [PMID: 12013465 DOI: 10.2460/ajvr.2002.63.660] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine which antimicrobials that are used to treat neonatal foals with septicemia attributable to Escherichia coli will minimize endotoxin release from bacteria and subsequent activity of inflammatory mediators while maintaining bactericidal efficacy. SAMPLE POPULATION Blood samples from 10 healthy foals. PROCEDURE Escherichia coli isolates A and B were isolated from 2 septicemic foals, and minimal inhibitory concentrations (MIC) were determined for 9 antimicrobials. Five of these antimicrobials were tested in vitro at 2 and 20 times their respective MIC. Whole blood or mononuclear cells grown in tissue-culture media were incubated with 105 colony-forming units of E. coli and each antimicrobial or saline (0.9% NaCl) solution. After 6 hours, number of viable bacteria remaining was determined, and supernatant was tested for endotoxin and tumor necrosis activity. RESULTS Testing in whole blood was compromised by bactericidal effects of the blood itself. In mononuclear cell suspensions, each antimicrobial significantly reduced the number of viable bacteria to low or undetectable amounts. Antimicrobials did not differ significantly in efficacy of bacterial killing. Amikacin used alone or in combination with ampicillin resulted in significantly less endotoxin activity than did ampicillin, imipenem, or ceftiofur alone. There was a correlation between TNF-alpha and endotoxin activity. CONCLUSIONS AND CLINICAL RELEVANCE Aminoglycosides appear less likely to induce endotoxemia and TNF-alpha synthesis during bactericidal treatment of E. coli septicemia, compared with beta-lactam antimicrobials. Use of ampicillin, imipenem, or ceftiofur in the treatment of septicemic neonatal foals should be accompanied by appropriate treatment for endotoxemia.
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Affiliation(s)
- Adrienne P Bentley
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602, USA
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MacKay RJ, Daniels CA, Bleyaert HF, Bailey JE, Gillis KD, Merritt AM, Katz TL, Johnson JC, Thompson KC. Effect of eltenac in horses with induced endotoxaemia. Equine Vet J 2000:26-31. [PMID: 11202378 DOI: 10.1111/j.2042-3306.2000.tb05330.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ten horses were used in a crossover study to evaluate the effectiveness of eltenac against endotoxaemia. Eltenac (0.5 mg/kg bwt) or saline control was given i.v. then 15 min later, intravenous infusion of endotoxin was begun and continued for 120 min (total dose 100 ng/kg bwt). Horses were monitored for heart and respiratory rates, pulmonary and carotid arterial pressure and core body temperature. Blood was sampled at intervals for measurement of haematological variables and plasma concentrations of lactate, prostanoid metabolites, tumour necrosis factor (TNF) and stress hormones. In comparison with saline-treatment, use of eltenac significantly protected against endotoxin-induced changes in respiratory rate, core temperature, systemic arterial blood pressure (SAP), pulmonary arterial pressure, PCV, and plasma protein, 6-keto prostaglandin F1 alpha, thromboxane B2, epinephrine, and cortisol concentrations. Despite statistical effect of eltenac on SAP, values in both treatment groups remained well above baseline throughout the evaluation period. Significant protective effect of eltenac was not found for heart rate, white blood cell count, plasma lactate concentration or TNF activity. On the basis of these results, it is expected that use of eltenac will provide clinical benefit in horses with naturally occurring endotoxaemia.
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Affiliation(s)
- R J MacKay
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA
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Abstract
As an assay for endotoxin, the Limulus amebocyte lysate assay has several desirable properties: sensitivity, specificity, and potential for adaptation to a quantitative format. Several modifications have been developed to enhance its potential for clinical application. The modifications that allow quantitative measurement of endotoxin and also improve its application to blood samples are described in this review. In fluids other than blood, the detection of endotoxin with the Limulus amebocyte lysate assay can be used as an aid to identify the presence of gram-negative bacteria, and the assay has established utility. With blood, however, there are a range of factors that interfere with the detection of endotoxemia and there are disparate views with respect to the diagnostic and prognostic significance of the test results. In general, the clinical significance of the finding of endotoxemia broadly parallels the frequency and importance of gram-negative sepsis in the patient groups studied and a decline in endotoxin levels accompanies clinical improvement. However, with therapies designed to reduce levels of endotoxin, or to antagonize its effects, it is unclear whether clinical improvement occurs as a consequence of changes in the levels of endotoxemia.
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Affiliation(s)
- J C Hurley
- Division of Infectious Diseases, Children's Hospital & Medical Center, Seattle, Washington, USA
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