As the number of bacteria resistant to antimicrobial drugs is increasing, the need for alternative antimicrobial agents is becoming more apparent. The conjugative plasmid pOX38a carrying the colicin E7 gene is an alternative antimicrobial. In order to test its efficiency, a ciprofloxacin resistant Escherichia coli N4i strain was needed, hence the goal of this thesis was to prepare such a strain. After initial characterization (plasmid isolation, mating assay on solid media, and bacteriocin production) of natural uropathogenic ciprofloxacin-resistant E. coli DL strains, which were a possible source of the ciprofloxacin resistance gene, we started to perform different transduction experiments in order to transfer the ciprofloxacin resistance gene into N4i. Since desipite several attemps we failed to transfer ciprofloxacin resistance gene with transduction, the ciprofloxacin-resistant bacterial strain N4i was grown by stepwise cultivation in media with increasing concentrations of ciprofloxacin. The genome of the obtained strain was sequenced using a GridIon instrument. The data obtained were processed using the appropriate MinKNOW software, followed by demultiplexing and identification of bases from the raw data using Guppy program. The genome was assembled de novo using the Flye algorithm. The assembled nucleotide sequence was compared with the deposited nucleotide sequence of strain Nissle 1917 in the NCBI database and analyzed, if the observed nucleotide differences were located in already known genes associated with resistance to fluoroquinolone antibiotics.
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