Povezanost mutatorskog svojstva i višestruke antiobiotičke rezistencije u uropatogenim izolatima bakterije Escherchia coli

master's thesis

• Title (english): The role of mutators in the emergence of multiple antibiotic resistance among uropathogenic Escherichia coli isolates
• Author: Tihana Tršan
• Mentor: Višnja Bačun-Družina (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biology and Microbial Genetics); Zagreb
• Defense date and country: 2005-04-18, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Bakterije antibiotičku rezistenciju stječu mutacijama ili horizontalnim transferom rezistentnih gena. U prirodnim izolatima patogenih bakterija pronađen je vrlo visok postotak mutatora. Većina spontanih mutatora ima nefunkcionalan sustav za popravak pogrešno sparenih baza (eng. ''Mismatch Repair System'', MMR). Stanice kojima je ovaj sustav inaktiviran pokazuju stopu mutacije i do 1000 puta veću nego sojevi divljeg tipa. MMR sustav također predstavlja barijeru za rekombinaciju između bakterija različitih vrsta te se uklanjajem te barijere povećava i frekvencija horizontalnog transfera gena. Kako bi se ispitala povezanost mutatorskog svojstva i antibiotičke rezistencije, u radu su analizirani uropatogeni izolati E. coli različitog rezistencijskog spektra. Pronađen je veći postotak mutatora među višestruko rezistentnim nego među rezistentnim i senzitivnim sojevima. Rezultati također pokazuju da do selekcije višestruko rezistentnih bakterija može doći i bez tretmana antibiotikom.

Abstract (english)

Bacterial antibiotic resistance can be acquired either by mutations or by horizontal transfer of resistance genes. Mutator strains have been found among natural isolates of pathogenic bacteria at higher frequencies than expected. Most spontaneous mutators appear to be defective in mismatch repair (MMR) system. Bacteria with inactivated MMR genes show increase in frequency of mutations up to 1000-fold higher than wild type strains. MMR system also act as barrier to recombination between divergent species and removal of this barrier enhances the frequency of horizontal gene transfer. In order to examine the link between high mutation frequency and antibiotic resistance, uropathogenic stains of E. coli that differ in their resistance spectra were analysed. It was found that mutators occur at higher frequencies among multidrug resistant strains than in resistant and sensitive population. These results also show that multidrug-resistant bacteria could be selected even without antibiotic treatment.

• Keywords: antibiotička rezistencija; Escherichia coli; frekvencija mutacije; mutatori
• Keywords (english): antibiotic resistance; Escherichia coli; mutation frequency; mutator bacteria
• Language: croatian
• URN:NBN: urn:nbn:hr:159:203531
• Study programme: Title: Biotechnology; specializations in: Biochemical-Microbiology; Course: Biochemical-Microbiology; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki (diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-13 10:43:11