Lactoferricin, a new antimicrobial peptide

Abstract

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 possible in vivo uses, 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 and Candida albicans. Proteus spp., Pseudomonas cepacia and Serratia spp. 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 role in vivo because of its sensitivity to changes in physical variables. It may be that lactoferricin exerts a transient antimicrobial effect at mucosal surfaces.

Bovine lactoferrin for Helicobacter pylori eradication: an open, randomized, multicentre study

“…14 A number of other potential mechanisms by which lactoferrin inhibits the growth of several microorganisms has been suggested, including structural changes in the microbial cell wall, complete loss of membrane potential and integrity, indirect effects on enzyme activation, an increased generation of metabolic by-products of aerobic metabolism, iron deprivation and a combination of these factors. [28][29][30][31][32] By using multiple points of attack against the bacterium, bLf plus clarithromycin and tinidazole may exert an optimal synergic anti-H. pylori activity that could lead to a complete destruction of the bacterium. Several in vivo and in vitro studies regarding a monotherapy of bLF against H. pylori infection showed equivocal results.…”

IncreasedStaphylococcus-killing Activity of an Antimicrobial Peptide, Lactoferricin B, with Minocycline and Monoacylglycerol

“…Therefore, instead of synergy analysis by MIC testing, we did mainly a killing test in a suspension. Because nutritionally rich medium or milk inhibits the antimicrobial activity of LFcin B, 16,18) we tried toˆnd antibiotics and substances that increase the killing activity of LFcin B in MuellerHinton broth and milk, respectively.…”

Antimicrobial peptides: A natural alternative to chemical antibiotics and a potential for applied biotechnology

“…Recently, a fraction enriched in a novel antibacterial domain from the N-terminal part of caprine lactoferrin (fragment 14 -42) has been recovered from its precursor protein bound to a cation-exchange membrane, followed by in-situ enzymatic cleavage with an appropriate enzyme and referred as lactoferricin-C (Jones et al 1994). Additionally, the Lactoccocus lactis lantibiotic nisin was also successfully released from its precursor polypeptide by the same procedure (Recio et al 2003).…”