The efficiency of the potential probiotic strain ŽP in in vitro models of human intestine

Lesar, Aleksander (author), Starčič Erjavec, Marjanca (mentor), Venema, Koen (co-mentor)

The emergence of antimicrobial resistance (AMR) is a global problem, as it reduces the effectiveness of antibiotics and makes the treatment of infections more difficult. Innovative alternatives, such as bacteriophage therapy, probiotics, and antimicrobial peptides, are being researched to tackle this problem. The ŽP strain, a genetically modified Escherichia coli Nissle 1917 was developed as a potential probiotic strain capable of killing pathogenic E. coli. The ŽP strain harbours a conjugative plasmid pOX38a:Cm that carries the gene for colicin E7 (ColE7) synthesis. In this study, the ŽP effect on uropathogenic E. coli DL82 was tested in an in vitro gastrointestinal model (TIM) simulating conditions in the lumen of the gastrointestinal tract. To determine the physiological effects of anaerobiosis on conjugation and killing rate of E. coli ŽP strain, the frequency of conjugation was also determined in an anaerobic chamber. We found that anaerobic conditions significantly reduced the conjugation frequency in the TIM simulating the conditions of colon and in the anaerobic chamber. Further, our results showed that the uropathogenic strain DL82 had better adaptational mechanisms to cope with harsh conditions in the TIM simulating the conditions of the gastrointestinal tract compared to the ŽP strain.

• Language: English
• Keywords: bacterial conjugation, Escherichia coli, probiotics, TNO gastrointestinal models, survival, anaerobic conjugation
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [A. Lesar]
• Year: 2024
• PID: 20.500.12556/RUL-155899
• UDC: 579.61:579.257:615.33
• COBISS.SI-ID: 193752067
• Publication date in RUL: 24.04.2024

Secondary language

• Language: Slovenian
• Title: Učinkovitost potencialnega probiotičnega seva ŽP v in vitro modelih človeške prebavne poti

Abstract

Pojav mikrobne odpornosti predstavlja svetovni problem, saj zmanjšuje učinkovitost antibiotikov in otežuje zdravljenje okužb. Inovativne alternative, kot so zdravljenje z bakteriofagi, probiotiki in protimikrobnimi peptidi, se raziskujejo za reševanje tega problema. Sev ŽP, genetsko spremenjena bakterija Escherichia coli Nissle 1917, je bil razvit kot potencialni probiotični sev, ki lahko uniči patogeno E. coli. Sev ŽP vsebuje konjugativni plazmid pOX38a:Cm, ki ima gen za sintezo kolicina E7 (ColE7). V tej študiji smo testirali učinek seva ŽP na uropatogeni sev E. coli DL82 v in vitro gastrointestinalnem modelu (TIM), ki simulira razmere v lumnu gastrointestinalnega trakta. Za ugotavljanje fizioloških učinkov anaerobioze na konjugacijo in stopnjo ubijanja seva ŽP smo določili tudi frekvenco konjugacije v anaerobni komori. Ugotovili smo, da so anaerobne razmere znatno zmanjšale frekvenco konjugacije v TIM, ki simulira pogoje debelega črevesa in v anaerobni komori. Nadalje so naši rezultati pokazali, da je imel uropatogeni sev DL82 boljše prilagoditvene mehanizme za spopadanje s težkimi razmerami v TIM, ki simulirajo razmere v prebavnem traktu, v primerjavi s sevom ŽP.

• Keywords: bakterijska konjugacija, Escherichia coli, probiotiki, TNO gastrointestinalni model, preživetvenost, anaerobna konjugacija