|Sanders, Jerry - UNIV.OF CA.,SAN DIEGO,CA.|
|Tagawa, Yuichi - UNIV.OF CA.,SAN DIEGO,CA.|
|Corbeil, Lynette - UNIV.OF CA.,SAN DIEGO,CA.|
Submitted to: Elsevier
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 15, 1997
Publication Date: N/A
Interpretive Summary: Haemophilus somnus causes respiratory and reproductive diseases of domestic and wild ruminant species. A system was developed for transferring foreign DNA into the bacterium. A gene thought to be involved in allowing H. somnus to cause disease was introduced into a strain which lacked the gene. The gene product was detected, but failed to transport outside the bacterium, and failed to confer the expected trait. The technique should be useful for determining the role of specific bacterial prodoucts in disease and to develop improved vaccines.
Technical Abstract: The role of a 76kDA surface antigen (p76) of Haemophilus somnus in virulence was investigated. The p76 gene from a virulent isolate of H. Somnus (strain 2336) was introduced into an asymptomatic carrier strain (129Pt) lacking this gene. This was accomplished by the development of a system for genetic exchange in H. Somnus. The cloned p76 gene was inserted dinto the broad host range vector pLS88, electroporated into H. influenzae for modification and then into the H. Somnus strain 129Pt. The recombinant plasmid was characterized from selected transformants and expression of the p76 protein was demonstrated by Western immunoblotting. However, transformants were not serum resistant and surface exposure of the recombinant protein could not be detected, suggesting that additional genetic elements might be required for export.