Lactoferricin, a new antimicrobial peptide

摘要

Lactoferricin B(LF‐B) is a peptide derived from acid‐pepsin digestion of bovine lactoferrin, which has antimicrobial properties. In order to assess the antimicrobial spectrum of LF‐B and its possiblein vivouses, the minimum inhibitory and microbicidal concentrations of pure lactoferricin B were determined for a range of bacterial species and under varying conditions of growth including growth phase and size of the inoculum, pH and ionic strength of the medium. Lactoferricin B was bactericidal against a wide range of bacteria andCandida albicans. Proteusspp.,Pseudomonas cepaciaandSerratiaspp. were resistant. The bactericidal activity of LF‐B was inhibited by increasing ionic strength and bacterial inoculum and at acid pH. The activity of lactoferricin B was completely inhibited by the addition of 5 whole cow's milk and was reduced in the presence of increasing concentrations of mucin. These results indicate the potential of LF‐B to reduce the numbers of organisms in a simple medium, but raise doubts about its rolein vivobecause of its sensitivity to changes in physical variables. It may be that lactoferricin exerts a transient antimicrobial effect at mucosal