The effect of cyclodextrin on lipopolysaccharide production in cultures of Bordetella pertussis

Abstract

The effect of adding 500 μg of (2,6-0-dimethyl) β-cydodexcrin (Me-β-CD) per ml of Stainer-Scholte (SS) medium in two-day shaker flask cultures of Bordetella pertussis on the production of lipopolysaccharide (LPS) was investigated. The amount of LPS per 10⁹ cells found in the supernatants of these cultures was either somewhat reduced or unaffected by comparison with the amounts in cultures grown in SS-medium alone. In addition, the time course of LPS release from cultures of B. pertussis strain 3843 cells during a 96-h growth period in normal and Me-β-CD-enriched SS medium is described. By using the enriched medium bacterial growth, the production of filamentous haemagglutinin (FHA) and of pertussis toxin (Pt) and the levels of haemagglutination and lymphocytosis-promoting activity were enhanced to various degrees. Measurements made on sedimented whole and on sonicated B. pertussis cells grown in the two media showed no differences in LPS content.

The reasons for the reduced/unaffected LPS production are discussed. It has been suggested that an interaction between hydrophobic cavities of the Me-β-CD molecules and the ‘lipid A’ part of LPS reduces the reactivity of LPS in the Limulus Amoebocyte Lysate (LAL) assay. This possibility, however, was rejected as the reactivity of Me-β-CD-spiked purified B. pertussis strain 3803 LPS, compared with unspiked samples, remained unchanged.