Imunomodulacijsko djelovanje odabranih bakterija mliječne kiseline

master's thesis

• Title (english): Immunomodulation activity by the selected lacic acid bacteria
• Author: Anita Keć
• Mentor: Jagoda Šušković (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Antibiotic, Enzyme, Probiotic and Starter Cultures Technology); Zagreb
• Defense date and country: 2007-10-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

U prethodnim istraživanjima, dokazana su probiotička svojstva tri soja bakterija mliječne kiseline: Lactobacillus acidophilus M92, Lactobacillus plantarum L4 i Enterococcus faecium L3. Probiotički soj Lactobacillus acidophilus M92 je pokazao najbolja imunomodulacijska svojstva što bi se moglo pripisati površinskom parakristalnom sloju, tzv. S-layer proteinu. Osim što potiče sintezu ukupnih IgA, IgG i IgM antitijela u serumima imuniziranih miševa, S-layer protein utječe i na bolje preživljavanje Lactobacillus acidophilus M92 u simuliranim uvjetima želučanog soka i soka tankog crijeva, što ukazuje na njegovu zaštitnu ulogu. Također, pokazalo se da je S-protein odgovoran za adheziju Lactobacillus acidophilus M92 na epitelne stanice tankog i debelog crijeva miševa u in vitro i in vivo pokusima. U svrhu postizanja pojačanog, sinbiotičkog učinka ispitana je asimilacija prebiotičkih supstrata s odabranim bakterijama mliječne kiseline u in vivo pokusima sa Swiss Albino miševima. Kao najbolji sinbiotički pripravci pokazali su se: L. acidophilus M92 u kombinaciji s inulinom, te L. plantarum L4 i E. faecium L3 u kombinaciji s laktulozom. Paralelno su provedena istraživanja imunomodulacijskog učinka ispitivanih probiotičkih sojeva i prebiotičkih supstrata na imunološki sustav miševa ELISA metodom. Adhezija ispitivanih probiotičkih sojeva u tankom i debelom crijevu pokusnih miševa potvrđena je induciranjem rezistencije ovih sojeva na rimfampicin te identifikacijom izoliranih bakterijskih sojeva iz crijeva miševa RAPD-PCR metodom.

Abstract (english)

In previous researches, three strains of Lactic Acid Bacteria with probiotic properties have been defined: Lactobacillus acidophilus M92, Lactobacillus plantarum L4 and Enterococcus faecium L3. Probiotic strain of L. acidophilus M92 has shown the highest immunomodulatory properties that could be attributed to the paracrystalline layer so called S-layer protein. Besides stimulating the synthesis of total IgA, IgG and IgM antibodies in immunized mice serum, S protein influences enhanced survival of L. acidophilus M92 under simulated conditions of gastric juice and intestinal juice, proving its protective function. Also, adhesive function of L. acidophilus M92 S protein has been shown on epithelial cells of mice small and large intestine in vitro as well as in vivo tests. The assimilation of probiotic substrates with selected lactic acid bacteria has been realized in vivo, with experimental Swiss Albino mice. The best synbiotic preparations, so far, have been: Lactobacillus acidophilus M92 in combination with inulin, Lactobacillus plantarum L4, and Enterococcus faecium L3 in combination with lactulose. The immunomodulatory effect on tested probiotic strains and prebiotic substrates on immunity system of mice was explored by ELISA method. Immunizing mice orally with synbiotic preparations has caused stronger immune response than individual probiotic strains and prebiotic substrates. Only synbiotic L. acidophilus M92, L. plantarum L4 and E. faecium L3 preparations using various prebiotic substrates have shown positive influence on intestinal microflora in mice due to the competitive exclusion of undesirable members of intestinal microflora, enterobacteria and sulphite reducing clostridia. The a adhesive function of tested probiotic strains in the small and large intestine of experimental mice has been confirmed by inducing the resistance of these strains on rimfampicin, and by identification of bacterial strains isolated from mice intestine by using RAPD-PCR method.

• Keywords: ELISA; imunomodulacija; Lactobacillus acidophilus; RAPD-PCR; S-sloj
• Keywords (english): ELISA; immunomodulation; Lactobacillus acidophilus; RAPD-PCR; S-layer
• Language: croatian
• URN:NBN: urn:nbn:hr:159:257815
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-06 07:45:49