magistrsko delo
Špela Zorko (Author), Andreja Čanžek Majhenič (Reviewer), Sonja Smole Možina (Mentor), Anja Klančnik (Co-mentor)

Abstract

Pritrjevanje bakterij in nadaljnja tvorba biofilmov na površinah živilsko-predelovalne industrije je zaskrbljujoče zaradi povečane odpornosti bakterij znotraj kompleksne mikrobne združbe. Ovrednotili smo adhezijo bakterij vrste Campylobacter jejuni na polistiren s spremljanjem kultivabilnosti in aktivnosti pritrjenih celic ter z določanjem njihove biomase. Razvili smo učinkovito metodo kvantifikacije adheriranih bakterijskih celic v mikrotitrski plošči s PCR v realnem času. Absolutno kvantifikacijo za pripravo umeritvene krivulje smo opravili z digitalnim PCR. Izbrali smo piščančji izolat C. jejuni K49/4 z najboljšo sposobnostjo pritrjevanja. V nadaljevanju smo preverjali protiadhezijski učinek pripravkov navadnega brina kot alternativno strategijo preprečevanja in kontrole pritrjevanja celic. Za ta namen smo pripravili šest pripravkov navadnega brina: fenolni izvleček jagod, dve frakciji fenolnega izvlečka, izolirano komponento amentoflavon, izvleček odpadnega materiala po destilaciji (proizvodnji alkoholne pijače ''brinjevca'') in eterično olje. Na podlagi vrednosti MIK za planktonske celice C. jejuni K49/4 smo za določanje protiadhezijskega delovanja izbrali subinhibitorno koncentracijo pripravkov. Vsi pripravki navadnega brina so zmanjšali adhezijo bakterij C. jejuni. Najčinkovitejša, fenolni izvleček in eterično olje, smo uporabili za testiranje protiadhezijskega učinka pri različnih pogojih rasti C. jejuni glede na: medij, hrapavost površine in rast v mešani kulturi z L. monocytogenes. Pripravka sta zelo dobro preprečevala adhezijo bakterij na polistiren. Uporaba izvlečkov navadnega brina predstavlja alternativno strategijo preprečevanja in kontrole pritrjevanja celic ter pomembno prispeva k nadzoru kontaminacije s patogenimi kampilobaktri.

Keywords

patogeni mikroorganizmi;Campylobacter jejuni;bakterijski biofilmi;adhezija;rastlinski izvlečki;navadni brin;Juniperus communis;fenolne spojine;eterično olje;protimikrobne snovi;protiadhezijska učinkovitost;molekularne tehnike;PCR;qPCR;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [Š. Zorko]
UDC: 579.67:547.9+547.56
COBISS: 4815992 Link will open in a new window
Views: 1946
Downloads: 839
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Other data

Secondary language: English
Secondary title: Quantification of anti-adhesive effects of common juniper (Juniperus communis) extracts on Campylobacter jejuni
Secondary abstract: Bacterial adhesion and further development of biofilms on food-related surfaces are concerning due to the increased resistance of microorganisms within the complex microbial community. Our study focused on adhesion of Campylobacter jejuni via monitoring culturability, activity of adhered cells and quantification of attached biomass. We have developed an effective method for the quantification of adhered bacterial cells in microtiter plate with real-time PCR. Absolute quantification for creating the standard curve was made with digital PCR. We have selected the most adhesive C. jejuni K49/4 chicken isolate. Further on we focused on evaluation of anti-adhesive effects of extracts from common juniper (Juniperus communis) as alternative strategy for prevention and control of bacterial cell adhesion. For this purpose, we prepared six extracts of common juniper: phenolic extract from berries, two phenolic fractions, isolated active compound amentoflavone, waste material extract after distillation (production of traditional drink “brinjevec”) and essential oil. Based on MIC values obtained for planktonic cells C. jejuni K49/4, we have selected subinhibitory concentration for extracts used to determine anti-adhesive effect. The adhesion of C. jejuni was reduced when treated with all juniper preparations. Phenolic extract and essential oil that showed the greatest anti-adhesive effect were used for further testing of adhesion under different growth conditions concerning: medium, surface roughness and mixed culture with L. monocytogenes. Juniper extracts expressed excellent anti-adhesion activity. Thus, the use of common juniper preparations can make an important contribution to the control of contamination with pathogenic campylobacters and thus to prevention of human infection.
Secondary keywords: pathogenic microorganisms;Campylobacter jejuni;bacterial biofilms;adhesion;plant extracts;common juniper;Juniperus communis;phenolic compounds;essential oil;antimicrobial compounds;anti-adhesive effectiveness;molecular techniques;PCR;qPCR;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: XI, 69 f.
ID: 10910288