The Effect of Stress on Host Defense System and on Lung Damage in Calves Experimentally Infected with Pasteurella Haemolytica Type A 1

Abstract

This paper describes the influence of stress, immediately before a massive inoculation of a logphase P. huemolyticu A 1 culture in brain-heart-infusion broth by fiberoptic bronchoscopy in 5 months old conventional calves.Differences in phagocytic cell function and numbers, lung function and lung tissue damage between stressed and non-stressed, infected calves were studied.Compared with the non-stressed calves before infection, the superoxide generation by blood polymorphonuclear leucocytes of the stressed animals was markedly reduced immediately after a 2 hours stress period, but it recovered within 3 days.The total numbers of phagocytic cells, harvested from lung lavage fluid 3 days after inoculation were twice as high in the non-stressed calves than in the stressed calves. In contrast, no differences in pulmonary lesions and functions were found between stressed or non-stressed calves. The role of several stress factors on infiltration and metabolic response of polymorphonuclear leucocytes in P. haemolyticu infections and the effects of bacterial endotoxin and leukotoxin on alveolar and vascular injury are discussed. U. S. Copyright Clearance Center Code Statement: 093 1 -184X/90/3707-0525$02.50/0

Pulmonary Lesions Induced by a Pasteurella Haemolytica Cytotoxin Preparation in Calves

“…From the decrease of systemic leukocytes with simultaneous increase of neutrophils in pulmonary lavage fluids in the acute stage of experimental P. haemolytica infection, suggesting neutrophil aggregation in the lungs (36,39), and from the marked neutrophilic exudation and subsequent degeneration observed in the lesions of naturally occurring (1) and experimental (2) pasteurellosis, it has been concluded that also in wiwo neutrophils might play an important role in the pathogenesis of the disease. Although massive neutrophilic accumulation may result in putrefactive necrosis, it cannot explain coagulation necrosis, a characteristic feature in spontaneous and experimental P. haemolytica infections (2,4,17). The presence of most bacterial antigen in the areas of coagulation necrosis and the morphology of the typical lesions have been thought evidence for a direct toxic effect of the cytotoxin on the lungparenchyma (4,17).…”

“…Although massive neutrophilic accumulation may result in putrefactive necrosis, it cannot explain coagulation necrosis, a characteristic feature in spontaneous and experimental P. haemolytica infections (2,4,17). The presence of most bacterial antigen in the areas of coagulation necrosis and the morphology of the typical lesions have been thought evidence for a direct toxic effect of the cytotoxin on the lungparenchyma (4,17). From the presence of pulmonary lesions .…”

Einfluss der thermischen Enthornung mit unterschiedlichem Schmerzmanagement auf die Gesundheit von Kälbern

“…Mononukleäre und neutrophile Blutzellen gestresster Kälber zeigen eine geringere Phagozytoseleistung und geringere Proliferationsraten gegenüber Noxen als Zellen nicht gestresster Kälber [29]. Des Weiteren konnten aus der bronchialen Lavageflüssigkeit ungestresster Kälber nach experimenteller Infektion dreifach höhere Konzentrationen phagozytierender Zellen gewonnen werden, als dies bei gestressten Kälbern der Fall war [30]. Da für die Enthornung von Kälbern belegt ist, dass es sich um einen Schmerz und Stress auslösenden Eingriff handelt [13] [31], lässt sich das Risiko für die Entwicklung von Erkrankungen der Atemwege hinreichend erklären.…”