Antimicrobial anionic peptide binds in vivo to Mannheimia (Pasteurella) haemolytica attached to ovine alveolar epithelium.
Endogenous antimicrobial peptide activity in vivo has rarely been demonstrated. To assess this, Mannheimia haemolytica (log(10) 10.20 cfu) was deposited into the lungs of adult sheep, which were killed at 0, 5, 10 and 20 min for necropsy. At 0 min, M. haemolytica appeared normal and monoclonal antibody to antimicrobial anionic peptide (AP) and Protein A-colloidal gold identified AP already bound to the bacterial surface. At 5-20 min, many organisms were distorted with flocculated intracellular constituents characteristic of AP cellular damage indicating that AP can bind to and presumably help inactivate organisms in vivo.
Heidari
Mohammad
M
Respiratory Diseases of Livestock Research Unit, US Department of Agriculture, Agricultural Research Service, National Animal Disease Center, PO Box 70, Ames, IA 50010, USA.
Hamir
Amir
A
Cutlip
Randall C
RC
Brogden
Kim A
KA
D000818:Animals; D000838:Anions; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001422:Bacterial Adhesion; D004797:Enzyme-Linked Immunosorbent Assay; D004848:Epithelium / Q000382:microbiology*; D008168:Lung / Q000473:pathology; D016978:Mannheimia haemolytica / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D008854:Microscopy, Electron; D010455:Peptides; D011663:Pulmonary Surfactants / Q000737:chemistry*; D012756:Sheep
D000838:Anions; D000900:Anti-Bacterial Agents; D000911:Antibodies, Monoclonal; D010455:Peptides; D011663:Pulmonary Surfactants