Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Infectious Bacterial Diseases Research » Research » Publications at this Location » Publication #61212
Title: THE EFFECT OF MAGAININ 2, CECROPIN, MASTOPARAN, AND MELITTIN ON BRUCELLA ABORTUS: DIRECT COMPARISON TO S. TYPHIMURIUM

Author
item Halling, Shirley

Submitted to: Veterinary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Bovine reproductive failure costs farmers and ranchers millions of dollars a year, and one cause of bovine reproductive failure is brucellosis. The bovine can be vaccinated to prevent brucellosis. However, the immune system does not eliminate the present live vaccine strain, S19, from every vaccinate. One mechanism the immune system uses to eliminate bacteria from the animal is antimicrobial peptides found in the white blood cells. The sensitivities to antimicrobial peptides of the present vaccine, S19, and a new candidate vaccine strain, RB51, were compared. In general, the antimicrobial peptides were more effective on RB51 than on S19. This suggests that the vaccine strain RB51 may be more efficiently eliminated from vaccinated animals than S19. This property would enhance the value of RB51 as a vaccine.

Technical Abstract: Antimicrobial peptides are widespread in nature and resistance to these types of peptides is directly related to pathogenicity of the facultative intracellular parasite, Salmonella typhimurium. Brucella abortus, which causes bovine brucellosis, is also a facultative intracellular parasite, but little is known about the effect of these peptides on brucellae. The effect of the alpha-helical polycationic peptides magainin 2, melittin, mastoparan, and cecropin on the viability of B. abortus 544 (type species), B. abortus S19 (vaccine strain), and B. abortus S2308 (vaccine challenge strain) was determined. Rough mutants of these strains and the rough candidate vaccine strain B. abortus RB51 were also tested. S. typhimurium was used as a control to confirm the efficacy of the peptides and for direct comparison. Though no significant differences in susceptibility to the polycationic peptides were found amongst the smooth strains of B. abortus, differences in susceptibility to the polycationic peptides were found between smooth and rough strains with some of the peptides. The brucellae were significantly more resistant to all the cationic peptides than S. typhimurium.