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ARS Home » Research » Publications at this Location » Publication #103116
Title: IDENTIFICATION OF PASTEURELLA HAEMOLYTICA IN A PUTATIVE CARRIER STATE IN BOVINE TONSILS

Author
item KALFA, V - VISITING SCI, TURKEY
item FRANK, GLYNN
item BROGDEN, KIM

Submitted to: Virulence Mechanisms of Bacterial Pathogens
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Healthy ruminants carry P. haemolytica serotypes A1 and A2 as inhabitants of the upper respiratory tract. These organisms reside on the mucosal surface with the normal flora in latency or a carrier state. During periods of stress, P. haemolytica serotype A1 proliferates and induces respiratory tract infection eventually leading to pneumonia. Although the organism can be found in tonsils, the exact nature of the carrier state is unknown. To find P. haemolytica-like organisms, pharyngeal and palatine tonsils were excised from cattle at necropsy, fixed in gluteraldehyde, and processed for electron microscopy. Protein A-colloidal gold (PA-CG) staining was performed on sections to identify P. haemolytica serotype A1. In both the pharyngeal and palatine tonsillar epithelium, PA-CG labeled organisms were seen. These organisms appeared morphologically normal and undamaged. They were located within large membrane-bound vesicles and occurred singly and in small groups. In addition, there were similar vesicles without organisms that contained PA-CG labeled antigen. The significance of this is not yet known although P. haemolytica antigens have been detected by others within epithelial cells by immunoperoxidase staining. In conclusion, P. haemolytica-like organisms were seen by electron microscopy within tonsillar tissue of healthy cattle in a putative carrier state.