Effect of antibiotic induced bacterial clearance in the udder on L-selectin shedding of blood neutrophils in cows with Escherichia coli mastitis (original) (raw)
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American Journal of Veterinary Research, 2004
Objective—To evaluate L-selectin (CD62L) and Mac-1 (CD11b) expression at the surface of blood and milk neutrophils during the early inflammatory response to Escherichia coli-induced mastitis in cows. Animals—6 healthy Holstein heifers in early lactation. Procedure—Blood and milk samples were collected before and after intramammary administration of 104 CFU's of E coli in the left mammary gland quarters. Bacterial counts and electrolyte concentrations in milk, rectal temperature, differential blood leukocyte counts, milk somatic cell counts, neutrophil viability, and the expression of CD62L and CD11b on blood and milk neutrophils were determined longitudinally. Results—Bacteria grew during the first 6 hours after inoculation with a pronounced leukocytic influx. Coincident with neutrophil influx was an increase in CD62L+ and CD11b+ milk neutrophils, as well as an improved viability of milk neutrophils. The peak of the inflammatory reaction was reached approximately 12 hours after ...
Journal of Dairy Research, 2000
We have studied the effect of treatment with enrofloxacin on local and general clinical signs and chemiluminescence of circulating polymorphonuclear leucocytes during experimentally induced Escherichia coli mastitis in cows immediately after parturition. Twelve cows were infected with 104 cfu Esch. coli P4[ratio ]O32 into both left quarters. Six cows received an intravenous injection of 5 mg enrofloxacin/kg at 10 h after infection and a second enrofloxacin treatment administered subcutaneously at 30 h post infection. The other six cows were controls that received no treatment. General clinical signs (fever, tachycardia, loss of appetite, reduced rumen motility and depression) were similar in both groups. Local clinical signs, such as swelling, pain and firmness of the inflamed mammary quarters, were less severe in the treated cows. We saw no difference in the appearance of the milk[ratio ]flecks and watery or purulent milk were observed in both groups. The beneficial effects of trea...
Journal of dairy science, 1990
The relationship between preinfection functions of blood neutrophils and outcome of experimental Escherichia coli mastitis was studied in 11 cows. Random migration, chemotaxis, phagocytosis, and chemiluminescence by neutrophils were determined in white blood cell suspensions, and in purified neutrophil suspensions. The course of E. coli mastitis (10(4) E. coli 0:157 in rear quarters) was monitored using clinical parameters, counts of E. coli in mastitic secretion, and milk production. Regressions were calculated for areas under curves of these parameters and preinfection activities of neutrophils. Chemiluminescence by nonstimulated neutrophils in white blood cell suspensions was negatively correlated with counts of E. coli in secretion and with losses in milk production. The chemotactic differential in white blood cell suspensions minus the chemotactic differential in purified suspensions of neutrophils referred to as delta varied from -.66 to +.50, indicating, respectively, inhibit...
Moderate Inflammatory Reaction During Experimental Escherichia coli Mastitis in Primiparous Cows
Journal of Dairy Science, 2004
Nineteen primiparous cows were experimentally infected in 2 quarters with 1 × 10 4 (group A) or 1 × 10 6 (group B) cfu of Escherichia coli P4:O32 per quarter within 2 to 4 wk after parturition. Blood and milk samples were collected from all primiparous cows at regular time intervals from d −4 to d +3 relative to inoculation. Milk production rapidly decreased in both groups during E. coli mastitis, but recovery appeared to be faster in group B at d + 1 postinfusion (p.i.). The milk production losses in the noninfected quarters were substantial on the day of inoculation, which is probably due to pronounced systemic effects. However, on d + 2 p.i. milk production in the noninfected quarters nearly reached preinfection levels, indicating a moderate clinical severity following intramammary inoculation. None of the other severity criteria evolved towards a severe response pattern. Reticulorumen motility was inhibited in both groups during E. coli mastitis. The clinical episode was short lasting in both groups. Rectal temperature, heart rate, blood leukocyte count, number of colony-forming units, milk somatic cell count and several indicators for the disintegration of the blood-milk barrier returned to normal values within 24 to 72 h p.i. Primiparous cows reacted with a moderate inflammatory response following intramammary infusion with a relatively high dose of E. coli. Despite the use of a high inoculum dose, primiparous cows in both groups showed pronounced resistance against severe intramammary E. coli infection. A possible effect of the inoculum dose could be present, however, further research into the effect of the inoculum dose on the inflammatory response should be performed.
Severity of E. coli mastitis is mainly determined by cow factors
Veterinary Research, 2003
Intramammary infections of dairy cows with Gram-positive bacteria such as Staphylococcus aureus (major cause of mastitis) have received a lot of attention because of their major economic impact on the dairy farm through production losses induced by an increase in somatic cell count. Management strategies, including greater awareness for efficient milking and hygienic measures, have limited the spread of Gram-positive bacteria and resulted in a significant decrease of proportion of S. aureus isolates and subclinical mastitis worldwide. Other organisms such as coliform subspecies and Streptococcus uberis, both environmental bacteria that cause clinical mastitis, have received less attention. Escherichia coli causes inflammation of the mammary gland in dairy cows around parturition and during early lactation with striking local and sometimes severe systemic clinical symptoms. This disease affects many high producing cows in dairy herds and may cause several cases of death per year in the most severe cases. It is well known that bacterial, cow and environmental factors are interdependent and influence mastitis susceptibility. Many studies, executed during the last decade, indicate that the severity of E. coli mastitis is mainly determined by cow factors rather than by E. coli pathogenicity. During E. coli mastitis, the host defense status is a cardinal factor determining the outcome of the disease. Today, we know that the neutrophil is a key factor in the cows' defense against intramammary infection with E. coli. Effective elimination of the pathogen by neutrophils is important for the resolution of infection and the outcome of E. coli mastitis. This review is a compilation of some major findings over the last 15 years concerning mainly host factors that modulate and influence neutrophil function and the mammary inflammatory reaction. The individual chapters address: virulence factors of E. coli strains, how neutrophils kill E. coli, connection between endotoxins, tumor necrosis factor-a and nitric oxide, severity classification of E. coli mastitis, lifespan of neutrophils, host factors that influence severity, tissue damage and production loss. dairy cow / Escherichia coli mastitis / neutrophil / severity
Veterinary research, 2011
ABSTRACT: The objective of the current study was to investigate (i) the outcome of experimentally induced Escherichia coli mastitis in primiparous cows during early lactation in relation with production of eicosanoids and inflammatory indicators, and (ii) the validity of thermography to evaluate temperature changes on udder skin surface after experimentally induced E. coli mastitis. Nine primiparous Holstein Friesian cows were inoculated 24 ± 6 days (d) after parturition in both left quarters with E. coli P4 serotype O32:H37. Blood and milk samples were collected before and after challenge with E. coli. The infrared images were taken from the caudal view of the udder following challenge with E. coli. No relationship was detected between severity of mastitis and changes of thromboxane B2 (TXB2), leukotriene B4 (LTB4) and lipoxin A4 (LXA4). However, prostaglandin E2 (PGE2) was related to systemic disease severity during E. coli mastitis. Moreover, reduced somatic cell count (SCC), few...
Research in veterinary science
The accumulation of leucocytes in milk and in teat cistern tissues, and the presence of the cytokines interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-gamma) in milk was studied during inflammation in the lactating ovine udder induced by Staphylococcus aureus and Escherichia coli. Milk and/or teat tissue samples were taken before and four, eight and 24 hours after inoculation. Both S aureus and E coli induced a significant accumulation of leucocytes in milk, S aureus from eight hours with a peak after 24 hours, and E coli from four hours, with a peak after eight hours. After the inoculation of S aureus the numbers of subepithelial neutrophils in the teat cistern tissues were increased after four hours and had increased further by eight hours. After the inoculation of E coli, tissue neutrophil numbers peaked at four hours and were still high at eight hour...
American Journal of Veterinary Research, 2004
Objective—To determine whether proinflammatory mediators and glucocorticoids affect CD62L(L-selectin) expression on peripheral blood neutrophils from cows in various stages of lactation.Animals—100 healthy dairy cows during early (13.1 ± 0.79 days after parturition; n = 31), peak (58.7 ± 1.64 days after parturition; 31), and mid (137.2 ± 2.59 days after parturition; 38) lactation.Procedure—In vitro effects of relevant proinflammatory mediators that are released in response to mastitis caused by gram-negative bacteria such as lipopolysaccharide (endotoxin), tumor necrosis factor-α, and platelet-activating factor (PAF) on CD62L expression on bovine neutrophils were assessed by flow cytometry. Influences of cortisol and dexamethasone on CD62L expression on bovine neutrophils were also investigated.Results—Basal CD62L expression on neutrophils from cows during early, peak, and mid lactation were similar. Lipopolysaccharide and tumor necrosis factor-α had no effect on CD62L expression on...