Učinak eteričnog ulja vrste Micromeria thymifolia (Scop.) Fritsch i pulegona na rast i tvorbu biofilma bakterije P. aeruginosa

master's thesis

• Title (english): Effect of Micromeria thymifolia (Scop.) Fritsch essential oil and pulegone on growth and biofilm production of P. aeruginosa
• Author: Iva Sičić
• Mentor: Gordana Maravić Vlahoviček (mentor)
• Committee member: Gordana Maravić Vlahoviček (predsjednik povjerenstva)
• Committee member: Sanda Vladimir-Knežević (član povjerenstva)
• Committee member: Daniela Jakšić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of biochemistry and molecular biology); Zagreb
• Defense date and country: 2020-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Pseudomonas aeruginosa je oportunistički patogen koji izaziva akutne ili kronične infekcije. Akutne infekcije su uzrokovane planktonskim oblikom bakterije. Kronične infekcije se najčešće razvijaju kod pacijenata s kroničnim ranama i imunokompromitiranih pacijenata i za njih su odgovorne kulture koje razviju biofilm. Brojni mehanizmi rezistencije, uključujući i biofilm, koje je ova bakterija razvila pridonose njezinoj otpornosti na djelovanje antibiotika što dodatno otežava odabir učinkovite terapije. Danas je izazov pronaći nove mogućnosti liječenja infekcija uzrokovanih P. aeruginosa, ali i ostvariti željeni učinak klasične terapije. Eterična ulja su tvari za koje se zna da posjeduju antimikrobna svojstva, ali mehanizmi djelovanja još nisu detaljno istraženi. Nova istraživanja pokazuju da pojedina eterična ulja imaju i antibiofilm učinak što može pridonijeti napretku terapije kroničnih infekcija P. aeruginosa. Cilj ovog rada bio je ispitati učinak eteričnog ulja biljne vrste Micromeria thymifolia (Scop.) Fritsch i pulegona na rast planktonskih stanica i tvorbu biofilma bakterije P. aeruginosa ATCC 27853, samostalno i u kombinaciji s tobramicinom nakon formiranja biofilma. Učinak na planktonske stanice određen je mjerenjem optičke gustoće kulture pri 570 nm. Količina nastalog biofilma određena je mjerenjem optičke gustoće kulture pri 540 nm nakon bojenja kristal violetom. Samostalni učinak eteričnog ulja vrste M. thymifolia (Scop.) Fritsch i pulegona na biofilm dodatno je prikazan kao biofilm indeks. Rezultati su pokazali da eterično ulje vrste M. thymifolia (Scop.) Fritsch i pulegon u uskom rasponu subinhibitornih koncentracija mogu učinkovito inhibirati rast planktonskih stanica P. aeruginosa ATCC 27853, samostalno i u kombinaciji s tobramicinom. Također je pokazano da eterično ulje vrste M. thymifolia (Scop.) Fritsch i pulegon u uskom rasponu subinhibitornih koncentracija mogu inhibirati razvoj biofilma. U kombinaciji s tobramicinom, eterično ulje vrste M. thymifolia (Scop.) Fritsch pri većini koncentracija je antagoniziralo učinak tobramicina na daljnji razvoj biofilma, a pulegon je imao antagonistički učinak pri svim koncentracijama. Ovaj rad će pružiti nove informacije i pridonijeti daljnjim istraživanjima novih mogućnosti liječenja infekcija bakterijom P. aeruginosa, ali i očuvanju postojeće terapije.

Abstract (english)

Pseudomonas aeruginosa is an opportunistic pathogen that causes acute or chronic infections. Acute infections are caused by the planktonic form of the bacterium. Chronic infections most commonly develop in patients with chronic wounds and immunocompromised patients, and are caused by biofilm-developing cultures. Numerous mechanisms of resistance, including biofilm, developed by this bacterium contribute to its antibiotics resistance, which further complicates the choice of effective therapy. Today, the challenge is to find new possibilities for the treatment of infections caused by P. aeruginosa, but also to achieve the best possible effect of classical therapy. Essential oils are substances that are known to possess antimicrobial effect, but the mechanisms of their action have not yet been thoroughly investigated. Recent research shows that certain essential oils also have an antibiofilm effect which may contribute to advances in therapy for the treatment of chronic P. aeruginosa infections. The aim of this study was to examine the effect of Micromeria thymifolia (Scop.) Fritsch essential oil and pulegone on planktonic cell growth and biofilm formation of P. aeruginosa ATCC 27853, alone and combined with tobramycin after biofilm formation. The effect on planktonic cell growth was determined by measuring the optical density of the culture at 570 nm. The amount of biofilm formed was determined by measuring the optical density of the culture at 540 nm, following the crystal violet staining. The independent effect of the M. thymifolia (Scop.) Fritsch essential oil and pulegone on the biofilm was additionally shown as a biofilm index. The results showed that the M. thymifolia (Scop.) Fritsch essential oil and pulegone can in narrow range of subinhibitory concentrations effectively inhibit the growth of P. aeruginosa ATCC 27853 planktonic cells, alone and combined with tobramycin. It has also been shown that the M. thymifolia (Scop.) Fritsch essential oil and pulegone can in narrow range of subinhibitory concentrations inhibit biofilm development. In combination with tobramycin, the M. thymifolia (Scop.) Fritsch essential oil at most concentrations antagonized the effect of tobramycin on the further development of the formed biofilm, and pulegone had an antagonistic effect at all observed concentrations. This paper will provide new information and contribute to further research into new treatment options for infections caused by P. aeruginosa, but also to the preservation of existing therapy.

• Keywords: Pseudomonas aeruginosa; biofilm; antibiofilm učinak; Micromeria; pulegon; eterično ulje; tobramicin
• Keywords (english): Pseudomonas aeruginosa; biofilm; antibiofilm effect; Micromeria; pulegone; essential oil; tobramycin
• Language: croatian
• URN:NBN: urn:nbn:hr:163:079735
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-11-15 14:37:39