magistrsko delo
Abstract
Naraščanje odpornosti patogenih bakterij na antibiotike ter odpornost biofilmskih oblik bakterij, ki so prisotne na abiotskih površinah v živilski industriji, predstavlja velik izziv pri zagotavljanju varne hrane. Trenutne raziskave so usmerjene v iskanje alternativnih učinkovin naravnega izvora in v mehanizem njihovega delovanja na bakterijske celice. Obenem je potreben razvoj hitrih, specifičnih in cenovno dostopnih metod za detekcijo in kvantifikacijo patogenih bakterij v živilskih proizvodnih obratih. V delu smo se osredotočili na adhezijsko sposobnost Gram negativnih bakterij C. jejuni in Gram pozitivnih bakterij L. monocytogenes ter optimizirali metodo za kvantifikacijo adheriranih bakterij. Z uporabo metode digitalnega PCR (dPCR) smo pripravili umeritveno krivuljo ter nadalje z uporabo metode PCR v realnem času (qPCR) določili število pomnožkov tarčne DNK, ki predstavlja premosorazmerno količino adheriranih bakterij na polistiren. Nato smo preverili protiadhezijsko učinkovitost naravnih učinkovin karvakrola, timola, α-pinena in epigalokatehin galata (EGKG) v subinhibitorni koncentraciji (0,1 mg/ ml). Posamezen dodatek karvakrola, timola in EGKG je inhibiral adhezijo za več kot 90 %. Več kot 99 % inhibicijo adhezije smo ugotovili pri kombiniranju karvakrola, timola in EGKG ter pri kombiniranju vseh štirih učinkovin. Naravne učinkovine predstavljajo alternativno strategijo pri preprečevanju adhezije bakterij ter posledično nastanka biofilma na abiotskih površinah.
Keywords
patogene bakterije;Campylobacter jejuni;Listeria monocytogenes;protimikrobne snovi;karvakrol;timol;[alfa]-pinen;epigalokatehin galat;protiadhezivna učinkovitost;adhezija;molekularne tehnike;absolutna kvantifikacija;PCR v realnem času;digitalni PCR;
Data
Language: |
Slovenian |
Year of publishing: |
2018 |
Typology: |
2.09 - Master's Thesis |
Organization: |
UL BF - Biotechnical Faculty |
Publisher: |
[G. Pretnar] |
UDC: |
579.24/.26:547.9:57.083.1 |
COBISS: |
4919672
|
Views: |
1490 |
Downloads: |
589 |
Average score: |
0 (0 votes) |
Metadata: |
|
Other data
Secondary language: |
English |
Secondary title: |
Quantification of antiadhesion effect of combined natural compounds on bacteria Campylobacter jejuni and Listeria monocytogenes with PCR based methods |
Secondary abstract: |
Increased antibiotic resistance of pathogenic bacteria and the resistance of bacterial biofilms on the abiotic surfaces in the food industry is a major challenge for ensuring food safety. Current research is focused on alternative components of natural origin as well as on the mechanisms of their action on bacterial cells. At the same time, there is an urgent need for development of fast, specific and cost-effective methods for detection and quantification of pathogenic bacteria in production facilities. In our research, we focused on adhesion of Gram negative C. jejuni and Gram positive L. monocytogenes bacteria. By combining digital PCR and real time PCR methods, we were able to quantify DNA amplicons, which are proportional to the quantity of cells that adhered on polystyrene surface. Furthermore, we evaluated the anti-adhesive effect of natural compounds, such as carvacrol, thymol, α-pinene and epigallocatechin gallate (EGCG). The addition of carvacrol, thymol and EGCG individually in subinhibitory concentration showed more than 90% reduction of adhesion. Moreover, more than 99% adhesion inhibiton was shown when combining the above three compounds and all four of them. As seen, the natural compounds present an efficient alternative strategy in prevention of bacterial adhesion and consequent biofilm formation. |
Secondary keywords: |
pathogenic microorganisms;Campylobacter jejuni;Listeria monocytogenes;antimicrobial compounds;carvacrol;thymol;[alpha]-pinene;epigallocatechin gallate;adhesion;anti-adhesive effectiveness;molecular techniques;absolute quantification;qPCR;dPCR; |
Type (COBISS): |
Master's thesis/paper |
Study programme: |
0 |
Embargo end date (OpenAIRE): |
1970-01-01 |
Thesis comment: |
Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo |
Pages: |
X, 54 f., [11] f. pril. |
ID: |
10941632 |