Submitted to: American Society of Microbiologists Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/1999
Publication Date: N/A
Technical Abstract: Pasteurella multocida (Pm) is a common bacterial pathogen of swine, cattle, chickens, turkeys, and domestic rabbits. There are 13 somatic serotypes of Pm (numbered 1-13) and these serotypes can occur in any of five separate capsular groups (lettered A, B, D, E and F). Several virulence factors have been suggested for Pm including lipopolysaccharide, adhesion factors and an exotoxin. There is evidence to suggest that bacterial lipases, particularly phospholipases, may play an important role in virulence. We examined lipase production for 13 serotypes of Pm. All strains (except serotype 2) produced a lipase active against various Tweens (20, 40, 80, and 85). Tween 20 was the best substrate for lipase activity. Pm 8 produced the most active lipase against Tween 20 (1,699.5 +/- 22.3 units of activity/g protein). Lipase production paralleled Pm growth and was maximal in the stationary phase. Pm lipase activity was optimal at pH 8.0. .Lipase activity of Pm 8 eluded from a Sepharose 2B column in the void volume, which indicates a very high molecular weight for this enzyme. These data indicate that Pm strains produce a lipase and this enzyme should be considered when examining the virulence of this organism.