Haemolysins of Vibrio parahaemolyticus strains passaged in mice.

Some phenotypically non-haemolytic strains of V. parahaemolyticus were observed to produce haemolysins after two passages in mices. Depending on the strain, both heat stable and heat labile haemolysins were induced. The heat stable haemolysin so induced, was immunologically different from the thermostable direct haemolysin produced by Kanagawa positive strains of V. parahaemolyticus.

Virulence of Vibrio vulnificus strains isolated from seafoods.

A study was carried out on the relation between virulence of V. vulnificus assessed by LD50 in mice and other markers. V. vulnificus strains isolated from seafoods had LD50 ranging from 10(3)-10(7) for mice. Strains showing LD50 10(6) or less were generally haemolytic and settled after boiling. Resistance to bactericidal action of serum and ability to take up congo red was shown by all the strains.