Antibacterial effects of lactoferrin and a pepsin-generated lactofferrin peptide againstHelicobacter pylori in vitro
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Helicobacter pylori is an etiologic agent of gastritis and peptic ulcer disease in humans. We investigated the antibacterial activities of lactoferrin and Lactoferricin® (an antimicrobial peptide derived from lactoferrin) against this bacterium. The minimum bactericidal concentrations of bovine and human lactoferrins were 1.25 to 2.50 mg/mL, while it was greater than 5.0 mg/L for bovine Lactoferricin®. Time-kill studies withH. pylori grown in brucella broth demonstrated that the antibacterial effects of the lactoferrins were dose-dependent within the range of 0.8 to 2.0 mg/mL and began when the cells were in the exponential phase of growth. Iron-saturated lactoferrin did not inhibit the growth ofH. pylori. Bovine Lactoferricin® showed only weak activity againstH. pylori in brucella broth, however, a rapid bactericidal effect was observed in 1% Bacto-peptone medium within 1 hour of exposure at concentrations in the range of 0.1 to 1.0 mg/mL. Under these conditions, bovine lactoferrin showed little effect. Moreover, bovine Lactoferricin® inhibited the urease activity ofH. pylori, which is one of the virulence factors of this bacterium. These results indicate thatH. pylori is susceptible to inhibition and inactivation by both lactoferrin and Lactoferricin® in laboratory media. The antibacterial effect of lactoferrin appeared to be dependent on its iron status, the cellular phase of growth, and has a mechanism of action different from that of Lactoferricin®.
Key wordslactoferrin Lactoferricin® Helicobacter pylori antibacterial effects urease activity
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- 1.George EB, William KG, Won KL, Joan ML, Anthony RD. Relation ofCampylobacter pyloridis to gastritis and peptic ulcer. J Infect Dis 1986; 153: 664–669.Google Scholar
- 3.Kato M, Asaka M, Katagiri M, Sukegawa M, Kagaya H, Nishikawa K, et al. Looking for Japanese regimens for the eradication ofHelicobacter pylori. Endoscopia Digestiva 1996; 8: 661–667 (in Japanese).Google Scholar
- 4.Diker KS, Hascelik G. The bactericidal activity of tea againstHelicobacter pylori. Lett Appl Microbiol 1994; 19: 299–300.Google Scholar
- 9.Bullen JJ, Rogers HJ, Griffiths E. Role of iron in bacterial infection. Curr Top Microbiol Immunol 1987; 80: 1–35.Google Scholar
- 11.Bellamy W, Takase M, Wakabayashi H, Kawase K, Tomita M. Antibacterial spectrum of lactoferricin B, a potent bactericidal peptide derived from the N-terminal region of bovine lactoferrin. J Appl Bacteriol 1992; 74: 432–479.Google Scholar
- 18.Suzuki T, Yamauchi K, Kawase K, Tomita M, Kiyosawa I, Okonogi S. Collaborative bacteriostatic activity of bovine lactoferrin with lysozyme againstEscherichia coli O111. Agric Biol Chem 1989; 53: 1705–1706.Google Scholar
- 23.Hennart PF, Brasseur DJ, Delogne-Desnoeck JB, Dramaix MM, Robyn CE. Lysozyme, lactoferrin, and secretory immunoglobulin A content in breast milk: influence of duration of lactation, nutrition status, prolactin status, and parity of mother. Am J Nutr 1991; 53: 32–39.Google Scholar
- 24.Masson PL, Heremans JF. Lactoferrin in milk from different species. Comp Biochem Physiol 1971; 39: 119.Google Scholar
- 30.Worst DJ, Otto BR, Graaff J. Iron-repressible outer membrane proteins ofHelicobacter pylori involved in heme uptake. Infect Immun 1995; 63: 461–465.Google Scholar
- 31.Catrenich CE, Makin KM. Characterization of the morphologic conversion ofHelicobacter pylori from bacillary to coccoid forms. Scand J Gastroenterol 1991; 26(suppl 181): 58–64.Google Scholar