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Inducible nitric oxide synthase and nitrotyrosine in listeric encephalitis: a cross-species study in ruminants.
Journal article

Inducible nitric oxide synthase and nitrotyrosine in listeric encephalitis: a cross-species study in ruminants.

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  • 2002-05-15
Published in:
  • Veterinary pathology. - 2002
Animals
Brain
Cattle
Cattle Diseases
Colony Count, Microbial
Encephalitis
Goat Diseases
Goats
Immunohistochemistry
Listeria monocytogenes
Listeriosis
Macrophage Activation
Macrophages
Nitric Oxide
Nitric Oxide Synthase
Nitric Oxide Synthase Type II
Reactive Oxygen Species
Retrospective Studies
Ruminants
Sheep
Sheep Diseases
Species Specificity
Tyrosine
English Listeria monocytogenes (LM) is a Gram-positive facultative intracellular bacterium that causes fatal meningoencephalitis in humans and ruminants. A current paradigm predicts that intracellular bacteria are controlled by nitric oxide (NO) whose synthesis is catalyzed by inducible nitric oxide synthase (iNOS). The ability of macrophages (Mphi) to express iNOS shows extreme interspecies variability. Here the expression of iNOS and synthesis of NO was studied in listeric encephalitis of cattle, sheep, and goats. iNOS was expressed by a subset of Mphi in cerebral microabscesses in all three species. The level of iNOS expression and the density of cells per lesion expressing iNOS was highest in cattle, intermediate in sheep, and lowest in goats. The accumulation of nitrotyrosine (NT), an indicator of local NO synthesis, was observed in lesions of cattle but not in those of small ruminants. The density of iNOS-expressing cells in lesions was inversely correlated with the number of bacteria. No species differences were observed in regard to reactive oxygen intermediate (ROI) production by stimulated granulocytes, using the flow cytometric dihydrorhodamine-123 (DHR) method indicating ROI generation. Thus, the marked species differences in iNOS expression, NT accumulation, and LM content in lesions of ruminants with listeric encephalitis are explained by different amounts of ROI produced. It suggests that variations in the ability of Mphi to synthesize NO are of pathophysiological significance in listeriosis.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/125
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