Decreased neutrophil bactericidal activity during phagocytosis of a slime-producing<i>Staphylococcus aureus</i>strain

Barrio, B Miranda; Vangroenweghe, Frédéric; Dosogne, Hilde; Burvenich, Christian

doi:10.1051/vetres:2000143

Cited by 23 publications

(19 citation statements)

References 24 publications

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“…The E. coli J5 vaccines also stimulate the production of antibodies directed against E. coli, which results in enhanced opsonization of the bacteria and more efficient phagocytosis. This should have been translated into higher values for ε, if we assumed a positive correlation between phagocytosis and killing, as observed by Barrio et al (2000) A final comment is about the observation of a higher peak of cfu in vaccinated than in unvaccinated cows inoculated with 10 4 cfu. This phenomenon may be explained by the fact that the J5 vaccine reduces only the severity of clinical symptoms but not necessarily the rate of new infection (Hogan et al, 1992).…”

Section: Stage 2: Estimation Of the Parametersmentioning

confidence: 83%

Mathematical Model of the Acute Inflammatory Response to Escherichia coli in Intramammary Challenge

Detilleux

Vangroenweghe

Burvenich

2006

Journal of Dairy Science

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We constructed a mathematical model of the early response to Escherichia coli infection of the mammary gland and explored the roles and interactions between inflammatory cells and bacteria. The model incorporates 3 equations that describe the interactions among bacteria, milk somatic cells, and blood leukocyte densities. These 3 equations were fitted to cell densities observed during acute inflammatory responses in unvaccinated and vaccinated heifers inoculated with 10 4

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Section: Stage 2: Estimation Of the Parametersmentioning

confidence: 83%

Mathematical Model of the Acute Inflammatory Response to Escherichia coli in Intramammary Challenge

Detilleux

Vangroenweghe

Burvenich

2006

Journal of Dairy Science

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“…The low viability of milk PMN observed in all stages of lactation, more specifically in early lactation, compared to the high values observed in blood [1,7,10], may be explained by a deficient energy level within the cells following the energy-consuming process of diapedesis through the bloodmilk barrier. The relative lack of energy source at the mammary gland level could compromise the viability of these resident milk PMN.…”

Section: % Overall Killing % Overall Killingmentioning

confidence: 89%

“…Phagocytosis and overall killing of S. aureus Newbould 305 was evaluated in a bacteriological assay according to Barta [2] and Barrio et al [1] with few modifications for milk. The assay was run in duplicate in Eppendorf  tubes (Netheler-Hinz GmbH, Hamburg, Germany) in a final volume of 1 mL with the following composition: 500 µL isolated cells (5 × 10 6 viable cells/mL), 100 µL S. aureus Newbould 305 suspension (1 × 10 8 CFU/mL) and 400 µL pooled bovine serum diluted to a final concentration (v/v) of 5% (complement-inactivated, 56°C, 30 min).…”

Section: Neutrophil Function Testsmentioning

confidence: 99%

Effect of milk sampling techniques on milk composition, bacterial contamination, viability and functions of resident cells in milk

et al. 2001

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-Three different milk sampling techniques were evaluated during milk sampling: a direct aseptic collection from the udder through a sterile cannula was used as the reference technique, compared with either a manual or a mechanical sampling method. In this study 30 high-yielding HolsteinFriesian dairy cows at different stages of lactation and free of udder infection were used. For each milk sample, the influence of milk sampling techniques was determined for the following parameters: somatic cell count, milk composition, bacterial contamination, viability, in vitro phagocytosis and overall killing of Staphylococcus aureus Newbould 305, and cellular chemiluminescence. Because milk sampling occurred throughout lactation, the differences between early, mid-and late lactation were estimated. It was concluded that bacterial contamination was not significantly different in manual milking samples and the reference technique; bacterial contamination was, however, significantly (P < 0.001) higher in machine milking samples than in the reference technique. Among the different sampling techniques, no significant effects on SCC, milk composition, viability and functions of the cells isolated from milk were observed. It was found that viability, intracellular killing and cellular chemiluminescence of milk PMN were significantly lower (P < 0.05) in early lactation compared to mid-lactation. Phagocytosis was significantly (P < 0.05) higher in early lactation compared to mid-and late lactation, and no significant differences were observed between mid-and late lactation. From this study, it can be concluded that despite a higher bacterial contamination obtained with the mechanical sampling method, the 3 milk sampling techniques described in this study can be used for the evaluation of milk cell functions. dairy cow / milk sampling technique / stage of lactation / milk composition / milk neutrophil functions Vet. Res. 32 (2001) 565-579 565

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“…Slime producing strains of S. aureus are more resistant to phagocytosis and intracellular killing by bovine PMN compared to non-slime producing strains [18]. The slime layer prevents binding of immunoglobulins to Fab sites on the cell membrane of S. aureus and enhances virulence of the organism by reducing phagocytosis and killing by PMN.…”

Section: Bactericidal and Respiratory Burst Activitymentioning

confidence: 99%

The bovine neutrophil: Structure and function in blood and milk

Paape¹,

Bannerman²,

et al. 2003

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-Migration of polymorphonuclear neutrophil leukocytes (PMN) into the mammary gland provide the first line of defense against invading mastitis pathogens. Bacteria release potent toxins that activate white blood cells and epithelial cells in the mammary gland to secrete cytokines that recruit PMN that function as phagocytes at the site of infection. While freshly migrated PMN are active phagocytes, continued exposure of PMN to inhibitory factors in milk such as fat globules and casein, leads to altered PMN morphology and reduced phagocytosis. In the course of phagocytosing and destroying invading pathogens, PMN release chemicals that not only kill the pathogens but that also cause injury to the delicate lining of the mammary gland. This will result in permanent scarring and reduced numbers of milk secretory cells. The life span of PMN is limited by the onset of apoptosis. To minimize damage to mammary tissue, PMN undergo a specialized process of programmed cell death known as apoptosis. Macrophages quickly engulf and phagocytose apoptotic PMN, thereby minimizing the release of PMN granular contents that are damaging to tissue. The PMN possess an array of cell surface receptors that allow them to adhere and migrate through endothelium and to recognize and phagocytose bacteria. One receptor found on phagocytes that is receiving considerable attention in the control of infections by Gram-negative bacteria is CD14. Binding of lipopolysaccharide (LPS) to membrane bound CD14 causes release of tumor necrosis factor-a and sepsis. Binding of LPS to soluble CD14 shed from CD14-bearing cells results in neutralization of LPS and rapid recruitment of PMN to the site of infection. Recent advances in the fields of genomics and proteomics should greatly enhance our understanding of the PMN role in controlling intramammary infections in ruminants. Further, manipulation of PMN, through either recombinant proteins such as soluble CD14 that enhance PMN response or agents that mediate PMN apoptosis, may serve as novel therapeutics for the treatment of mastitis.

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Decreased neutrophil bactericidal activity during phagocytosis of a slime-producingStaphylococcus aureusstrain

Cited by 23 publications

References 24 publications

Mathematical Model of the Acute Inflammatory Response to Escherichia coli in Intramammary Challenge

Mathematical Model of the Acute Inflammatory Response to Escherichia coli in Intramammary Challenge

Effect of milk sampling techniques on milk composition, bacterial contamination, viability and functions of resident cells in milk

The bovine neutrophil: Structure and function in blood and milk

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