61C-17 |
Inhibitory activity against Helicobacter pylori by bacteriocins of lactic acid bacteria |
T. S. Kim1, M. A. YU2, J. W. Hur1, C. J. Lee2, K. N. Kim1, and Y. R. Pyun2. (1) R&D Center, Pulmuone, Co, Ltd., 134 Shinchon-Dong, Suhdaemoon-Gu, Seoul, 120-749, South Korea, (2) Department of Biotechnology & Bioproducts Research Center, Yonsei University, Seoul, 120-749, South Korea Helicobacter pylori is the most important etiologic factor of gastritis and peptic ulcer of humans. Eradication of H. pylori is critical in the treatment and prevention of the peptic ulcers. Although H. pylori is susceptible to most antibiotics, it is extremely difficult to eradicate the pathogen in vivo. In addition significant adverse effects as well as antibiotic resistance have been reported. Lactic acid bacteria (LAB) are GRAS and have been used as probiotics in fermented foods to inhibit undesirable microorganisms. Objective of the study was to investigate the antimicrobial activity of bacteriocins of LAB against H. pylori. Bacteriocins used for the study were produced by the following strains; Lactococcus lactis strains ATCC11454, A164, BH5, JW3, and NK24, Pediococcus acidilactici PO2 and Leuconostoc sp. LAB145-3A. Growth inhibition was determined by adding the culture supernatant to H. pylori cultures and monitoring growth at 600nm. Among the bacteriocins tested, lacticin A164 produced by L. lactis subsp. lactis A164, a strain isolated from Kimchi, showed the strongest growth inhibition (4-log cycle) against H. pylori DSM10242. When further investigated using 8 clinical isolates, five strains of H. pylori were effectively killed by lacticin A164 while the others were moderately sensitive to the peptide. Growth inhibition of H. pylori by lacticin A164 was dependant on initial inoculum size of the pathogen as well as concentration of the bacteriocin added. In vivo animal test using Mongolian Gerbils infected with H. pylori ATCC43504 showed preventative effect of lacticin A164. These results indicate that lacticin A164 can be developed as an anti-H. pylori regimen that may be an attractive substitute to antibiotic treatment in vivo. The regimen may contribute to reduce the infection of H. pylori in humans.
Session 61C, Food Microbiology: General I
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