Increase in the susceptibility of Salmonella strains to bactericidal activity of cord serum following treatment with agents disturbing surface structures.

Salmonella strains resistant to normal cord serum were found to become susceptible to it when the outer membrane was damaged by colistin, adult normal serum or Tris-HCl buffer. The present results indicate that after such treatment cord sera exert bactericidal effect, despite significant deficiencies in factors playing an essential role in this process.