Serum sensitivity and lipopolysaccharide characteristics in Bordetella bronchiseptica, B. pertussis and B. parapertussis.

The viability of four strains of Bordetella bronchiseptica, two strains of B. pertussis and one strain of B. parapertussis exposed to hyperimmune and pre-colostrum porcine serum was examined. Viable cell numbers (cfu/ml) of the B. pertussis strains and a rough strain of B. bronchiseptica (CSU-P-1) decreased by 99% and 99.99%, respectively, after exposure for 1 h to porcine hyperimmune serum. In contrast, smooth B. bronchiseptica strains and the B. parapertussis strain showed no significant decrease in viable cell numbers after the same treatment. B. bronchiseptica strain CSU-P-1 also showed a 99% decrease in viable cell numbers after exposure to pre-colostrum porcine serum for 1 h whereas the other strains tested showed no decrease in viable numbers under the same conditions. Heating the hyperimmune and pre-colostrum serum at 56 degrees C for 30 min resulted in the loss of bactericidal activity suggesting the involvement of complement in both systems. Analysis of silver-stained SDS-PAGE profiles of lipopolysaccharide (LPS) extracted from the bacterial cells indicated that the smooth strains of B. bronchiseptica and the B. parapertussis strain possessed high mol. wt O-side chain-like material, whereas the B. pertussis strains and B. bronchiseptica strain CSU-P-1 did not. Gel filtration of acid-hydrolysed LPS samples indicated two distinct carbohydrate peaks for the strains with high mol. wt O-side chain-like material, whereas the other strains each yielded one distinct peak. Western-blot analysis indicated a positive reaction for anti-B. bronchiseptica antibodies to the high mol. wt O-side chain-like material of all serum-resistant strains used in this study.(ABSTRACT TRUNCATED AT 250 WORDS)