Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Skof, A.
Phenotypic and genotypic characterization of antibiotic-resistant escherichia coli isolates from river water.
[ Diplomarbeit/Master Thesis (UNI) ] University of Graz; 2017. pp.108.
- Autor*innen der Med Uni Graz:
- Skof Aline
- Betreuer*innen:
- Zarfel Gernot
- Altmetrics:
- Abstract:
- Since the beginning of the century the number of resistant and multi-resistant bacteria has increased dramatically. Furthermore, antibiotic-resistant bacteria are no longer primarily restricted to the health care system. Enterobacteriaceae with the famously representative Escherichia coli (E. coli) plays a major role in the spread of multi-resistant bacteria and seems to become omnipresent in the environment. In this study, the presence and diversity of resistant and multi-resistant (including ESBL-harboring) E. coli in two rivers in Austria, the Mur and Drava were investigated. E. coli were isolated from river sediment and water samples and tested on their genetic and phenotypic profile. A biochemical fingerprinting method provided four big clones from different sample origins, with similar and different resistance patterns. Most resistances in E. coli river isolates were detectable to ampicillin, amoxicillin-clavulanic acid, tetracycline and nalidixic-acid. The antibiogramms revealed 15 ESBL-harboring E. coli isolates. The dominant β-lactamases in river samples were CTX-M-15 and CTX-M-1 which were expected due to their dominance in humans and animals. The dominant sequence types (ST) were ST940 and ST131. A new ST, related to ST224 was also detectable. In total, 14 different plasmids were detectable the dominant was FIB. In addition, clinical ESBL-harboring E. coli isolates were compared in growth and in their conjugation behavior with the river isolates. The conjugation and growth behavior of the clinical and river isolates was investigated at two different temperatures. The river isolates were more capable of conjugation at low temperatures than the clinical isolates. The growth behavior in the tested samples was similar under all tested conditions but the total river isolates were ahead of the clinical isolates under all tested conditions.