Utjecaj eteričnog ulja biljnih vrsta Micromeria thymifolia (Scop.) Fritsch i Calamintha officinalis na proteolitičku aktivnost i pokretljivost bakterije Pseudomonas aeruginosa

master's thesis

• Title (english): Influence of Micromeria thymifolia (Scop.) Fritsch and Calamintha officinalis essential oils on proteolytic activity and motility of Pseudomonas aeruginosa
• Author: Nives Kerner
• Mentor: Gordana Maravić Vlahoviček (mentor)
• Committee member: Gordana Maravić Vlahoviček (predsjednik povjerenstva)
• Committee member: Maja Šegvić Klarić (član povjerenstva)
• Committee member: Maja Bival Štefan (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of biochemistry and molecular biology); Zagreb
• Defense date and country: 2021-07-02, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Pseudomonas aeruginosa je kao oportunistički patogen postao jedan od najčešćih uzročnika bolničkih infekcija. Može dovesti do ozbiljnih posljedica nakon infekcije pluća, kože, oka, rana te urinarnog trakta. Ima vrlo razvijenu sposobnost ekspresije mnoštva faktora virulencije koji mu omogućavaju kolonizaciju tkiva domaćina, njegovo uništavanje te obranu od imunosnog sustava. Također ima učinkovite načine izbjegavanja djelovanja antibiotika što otežava liječenje infekcija. Bakterijska međustanična komunikacija omogućava stvaranje i izlučivanje faktora virulencije te razne bakterijske aktivnosti poput pokretljivosti u obliku plivanja i rojenja, stvaranja biofilma, sekundarnih metabolita, korištenja hemoglobina kao izvora željeza te antibiotičke rezistencije. Kako bi se smanjila doza antibiotika korištenih u borbi protiv patogenih bakterija razmatra se utjecaj eteričnih ulja zasebno, te u kombinaciji sa antibioticima. Eterična ulja su prirodni, lako hlapljivi spojevi podrijetlom iz biljaka koji se u tradicionalnoj medicini koriste kao antispazmodici, emenagozi, diaforetici, diuretici, karminativi i ekspektoransi, ali imaju dokazano antibakterijsko, antivirusno i antifungalno djelovanje. U ovom radu je ispitan utjecaj eteričnih ulja biljnih vrsta Micromeria thymifolia (Scop.) Fritsch i Calamintha officinalis u koncentraciji 0,5 mg/mL te aminoglikozidnog antibiotika tobramicina u subinhibitornim koncentracijama 0,5 μg/mL i 2 μg/mL na proteolitičku aktivnost i pokretljivost raznih sojeva P. aeruginosa. Uočena je razlika u ponašanju sojeva i njihovoj reakciji na dodatak tobramicina i eteričnih ulja pojedinačno te u kombinaciji. Tobramicin se pokazao djelotvoran u inhibiciji proteolitičke aktivnosti i rojenja za sojeve PAO1, PA14 i ATCC 27835, ali ne i za visoko rezistentni soj BB1285 (rmtD+). Eterična ulja pokazuju inhibitoran učinak na proteolitičku aktivnost soja PA14, potiču proteolitičku aktivnost soja ATCC 27835, a na sojeve PAO1 i BB1285 (rmtD+) u korištenoj koncentraciji nemaju izražen učinak. Oba ulja inhibiraju rojenje sojeva PAO1 i PA14, no jači učinak pokazuje ulje Micromeria thmifolia (Scop.) Fritsch, moguće zbog većeg udjela pulegona. Na soj ATCC 27835 oba ulja djeluju inhibitorno, a na BB1285 (rmtD+) promotivno, ali jednakom jačinom. Oba ulja u kombinaciji s tobramicinom imaju sinergistički učinak na smanjenje proteolitičke aktivnosti svih sojeva osim BB1285 (rmtD+) na kojem se ne opaža učinak. Kombinacija eteričnih ulja i antibiotika djeluje promotivno na rojenje soja BB1285 (rmtD+), a na sve ostale sojeve inhibitorno. Sinergistički učinak eteričnih ulja i antibiotika je zapažen kod soja PA14, dok je kod sojeva ATCC 27835 i PAO1 pri višim koncentracijama tobramicina učinak antagonistički. Ovaj rad pridonosi naporima u razumijevanju još do sada nerazjašnjenih mehanizama međudjelovanja eteričnih ulja i antibiotika te stvara temelj za daljnja istraživanja usmjerena prema traženju novih opcija liječenje infekcija uzrokovanih bakterijom P. aeruginosa.

Abstract (english)

As an opportunistic pathogen, Pseudomonas aeruginosa has become one of the most common causes of nosocomial infections. It can lead to serious consequences after infection of the lungs, skin, eyes, wounds and urinary tract. It has a strong ability to express many virulence factors that allow it to colonize and destroy host tissue and evade the immune system. It also shows many ways to avoid the effects of antibiotics, which makes infections difficult to treat. Quorum sensing enables the production and secretion of virulence factors and various bacterial activities such as motility in the form of swimming and swarming, biofilm formation, production of secondary metabolites, the use of hemoglobin as a source of iron and antibiotic resistance. To reduce the dose of antibiotics for treatment of bacterial infections, the use of essential oils is considered separately, and in combination with antibiotics. Essential oils are natural, easily volatile compounds derived from plants that are used in traditional medicine as antispasmodics, emmenagogues, diaphoretics, diuretics, carminatives and expectorants, and have shown antibacterial, antiviral and antifungal activity. This work examined the effect of essential oils of plant species Micromeria thymifolia (Scop.) Fritsch and Calamintha officinalis at a concentration of 0,5 mg/mL and the aminoglycoside antibiotic tobramycin at subinhibitory concentrations of 0,5 μg/mL and 2 μg/mL on proteolytic activity and swarming of various strains of P. aeruginosa. The addition of tobramycin and essential oils individually and in combination showed different effects on different strains. Tobramycin was effective in inhibiting proteolytic activity and swarming for strains PAO1, PA14 and ATCC 27835, but not for the highly resistant strain BB1285 (rmtD+). Essential oils showed an inhibitory effect on the proteolytic activity of strain PA14, stimulated the proteolytic activity of strain ATCC 27835, while on strains PAO1 and BB1285 (rmtD+) did not show notable effect. Both essential oils inhibit the swarming of PAO1 and PA14 strains, but stronger effect is shown by Micromeria thmifolia (Scop.) Fritsch oil, possibly due to the higher proportion of pulegone. Both oils in combination with tobramycin have a synergistic effect on reducing the proteolytic activity of all strains except BB1285 (rmtD+), on which no effect is observed. The combination of essential oils and antibiotics showed promotive swarming effect for BB1285 (rmtD+), and inhibitory effect on swarming of all other strains. A synergistic effect of essential oils and antibiotics was observed in strains PA14, while in strains ATCC 27835 and PAO1 at higher concentrations of tobramycin the effect was antagonistic. This work supports the efforts to understand the mechanisms of the interaction of essential oils and antibiotics and provides a basis for further research to find new treatment options for infections caused by P. aeruginosa.

• Keywords: Pseudomonas aeruginosa; bakterijska međustanična komunikacija; eterično ulje; Micromeria Thymifolia (Scop.) Fritsch; Calamintha officinalis; pulegon; tobramicin; proteolitička aktivnost; rojenje
• Keywords (english): Pseudomonas aeruginosa; quorum sensing; essential oil; Micromeria thymifolia (Scop.) Fritsch; Calamintha officinalis; pulegone; tobramycin; proteolytic activity; swarming
• Language: croatian
• URN:NBN: urn:nbn:hr:163:931084
• 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: 2022-02-03 08:52:40