Cytopathic effects of Moraxella bovis on cultured bovine neutrophils and corneal epithelial cells.
The effects of Moraxella bovis on the morphologic features of purified bovine neutrophils and bovine corneal epithelial cells were examined, using transmission and scanning electron microscopy and light microscopy. Within 2 minutes after incubation of bovine neutrophils with living M bovis, electron microscopic cellular changes included vacuolation, swelling, and loss of microplicae. Most of the neutrophils were lysed by 10 minutes of incubation. Human neutrophils phagocytosed the M bovis and remained intact, even after 30 minutes of incubation with the bacteria. Living M bovis killed bovine corneal epithelial cells in vitro. Sterile filtrates prepared from 6-hour shaker cultures of M bovis also killed bovine corneal epithelial cells, but the cytotoxic activity was less than that produced by the living bacteria. Cellular changes were first observed in specimens collected 1 hour after corneal cell monolayers were inoculated with sterile culture filtrates. The changes in these cells included pit-like lesions on the cellular surface, cellular separation, and vacuolation.
Kagonyera
G M
GM
Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616.
George
L W
LW
Munn
R
R
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D003315:Cornea / Q000382:microbiology* / Q000648:ultrastructure; D004848:Epithelium / Q000382:microbiology / Q000648:ultrastructure; D006801:Humans; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009016:Moraxella / Q000254:growth & development / Q000502:physiology*; D009504:Neutrophils / Q000382:microbiology* / Q000648:ultrastructure