diplomsko delo
Zala Gostenčnik (Author), Polona Jamnik (Reviewer), Anja Klančnik (Mentor)

Abstract

Bakterije vrste C. jejuni so ene od najpogostejših povzročiteljev gastroenteritisa pri človeku. Njihova večja odpornost znotraj oblikovanega biofilma na različnih površinah predstavlja velik problem v proizvodnji varnih živil. Eden od mehanizmov odpornosti na protimikrobne snovi so izlivne črpalke, ki izločajo protimikrobne učinkovine iz celice ter tako prispevajo k povečani odpornosti bakterij. V bakterijah vrste C. jejuni so prisotni sistemi črpalk CmeABC, CmeDEF in CmeGH. V nalogi smo uporabili divji sev C. jejuni NCTC 11168 in pet sevov mutant z izbrisom genov v izlivnih črpalkah cmeB, cmeR, cj1687, cmeF in cmeG. Namen naloge je bil: (i) določiti sposobnost tvorbe biofilma divjega seva ter mutant C. jejuni; (ii) določiti odpornost nastalega biofilma divjega seva ter mutant na etanolni izvleček kraškega šetraja in biocid benzalkonijev klorid; ter (iii) določiti mehanizem odpornosti biofilmskih celic na te protimikrobne učinkovine. Dokazali smo, da so bakterije vrste C. jejuni sposobne tvorbe biofilma na polistirenu ter nerjavnem jeklu. Sevi mutant v cj1687, cmeF in cmeG tvorijo manj biofilma, kar dokazuje vpletenost sistema izlivnih črpalk že v mehanizem nastanka biofilma. Izlivne črpalke so aktivno vključene tudi v odpornost že tvorjenega biofilma, saj je bil biofilm sevov mutant manj odporen na izvleček kraškega šetraja, medtem ko je bil bolj odporen na biocid benzalkonijev klorid. Izlivne črpalke so vključene v mehanizem odpornosti biofilmskih in planktonskih celic proti kraškemu šetraju in benzalkonijevemu kloridu.

Keywords

Campylobacter jejuni;biofilm;izlivne črpalke;odpornost biofilma;mehanizem odpornosti biofilmskih celic;protimikrobne učinkovine;kraški šetraj;benzalkonijev klorid;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [Z. Gostenčnik]
UDC: 579.22/.26:547.9:615.281
COBISS: 4947832 Link will open in a new window
Views: 945
Downloads: 281
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Other data

Secondary language: English
Secondary title: ǂThe ǂeffect of mutations in efflux pumps genes on the characteristics of Campylobacter jejuni biofilm
Secondary abstract: C. jejuni is one of the most common causes of gastroenteritis in humans. Bacteria are capable of adhesion to surfaces and biofilm formation. Biofilm protects cells against external influences, which can be a major problem for consumer safety. One of the mechanisms of resistance to antimicrobial substances is efflux pumps. Their task is the secretion of toxic antimicrobial compounds from the cell. They also contribute to the increased resistance of bacteria. CmeABC, CmeDEF and CmeGH efflux pumps are found in C. jejuni. In the thesis we used wild type strain C. jejuni NCTC 11168 and five mutants with deletion into cmeB, cmeR, cj1687, cmeF and cmeG. We used winter savory ethanol extract and benzalkonium chloride. The purpose was: (i) to determine the ability of the bacteria to form biofilm on the steel surface; (ii) to determine the resistance of the formed biofilm on the polystyrene surface of efflux pump mutants and wild type strain to the select antimicrobial substances; and (iii) to determine the resistance of biofilm cells to these antimicrobial substances. We found that C. jejuni bacteria are capable of adhesion on polystyrene and stainlesss steel. Mutants in cj1687, cmeF and cmeG have lower ability to form biofilm on a steel surface, which proves the involvement of efflux pump systems in the mechanism of biofilm formation. Efflux pumps are actively involved in the resistance of a formed biofilm, since the biofilm of mutans was less resistant to winter savory extract and more resistant to benzalkonium chloride. Efflux pumps are involved in the resistance mechanism of biofilm and planktonic cells against winter savory extract and benzalkonium chloride.
Secondary keywords: Campylobacter jejuni;biofilm;efflux pumps;biofilm resistance;resistance mechanism of biofilm cells;antimicrobial susbstances;winter savory;benzalkonium chloride;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VII, 24 f.
ID: 10959623