Projects / Programmes source: ARIS

Molecular Biology of Microorganisms

Research activity

Code Science Field Subfield
1.05.00  Natural sciences and mathematics  Biochemistry and molecular biology   
3.01.00  Medical sciences  Microbiology and immunology   

Code Science Field
B000  Biomedical sciences   

Code Science Field
1.06  Natural Sciences  Biological sciences 
3.01  Medical and Health Sciences  Basic medicine 
Evaluation (rules)
source: COBISS
Researchers (12)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  13654  PhD Jerneja Ambrožič Avguštin  Biochemistry and molecular biology  Researcher  2013 - 2017  251 
2.  30435  Gregor Bajc    Technical associate  2013 - 2016  35 
3.  09836  PhD Blagajana Herzog-Velikonja  Biochemistry and molecular biology  Researcher  2013 - 2015  120 
4.  30736  PhD Simona Kamenšek  Medical sciences  Junior researcher  2013  15 
5.  39099  PhD Katja Molan  Biochemistry and molecular biology  Junior researcher  2016 - 2017  39 
6.  20788  PhD Lejla Pašić  Biochemistry and molecular biology  Researcher  2013 - 2016  87 
7.  29420  PhD Živa Petkovšek  Microbiology and immunology  Researcher  2013  26 
8.  06902  PhD Zdravko Podlesek  Biochemistry and molecular biology  Researcher  2013 - 2017  137 
9.  15328  PhD Kristina Sepčić  Biochemistry and molecular biology  Researcher  2013  723 
10.  16064  PhD Marjanca Starčič Erjavec  Biochemistry and molecular biology  Researcher  2013 - 2017  438 
11.  16103  PhD Polona Zalar  Microbiology and immunology  Researcher  2014  461 
12.  07042  PhD Darja Žgur Bertok  Biochemistry and molecular biology  Head  2013 - 2017  441 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0481  University of Ljubljana, Biotechnical Faculty  Ljubljana  1626914  66,549 
Within the framework of our research we will continue our studies of pathogenic E. coli producing extended spectrum beta-lactamases (ESBL) and carbapanemases. We will also investigate strains sequence type STS131, resistant against a number of clinically significant antibiotics and attempt to elucidate the molecular mechanisms underlying their successful dissemintaion, focusing on two potentially significant virulence factors USP (uropathoegnic specific protein) and the autotransporter Ag43 flu. Bacterial persisters which are not antibiotic resistant but antibiotic tolerant, also play a decisive role in diminished efficiency of antibiotics. This small proportion of cells are antibiotic tolerant due to metabolic inactivity and become a potential threat as antibiotic therapy is completed. To elucidate the persister formation we will study persisters among selected and isolated mutants and attempt to determine conditions precluding their formation. Within the framework of our research program we also wish to enhance our konwledge of commensal E. coli strains as well as environmental E. coli strains. We will collect and characterize as large as possible number of E. coli strains from a wide range of sources at the molecular level, including antibiotic resistances, virulence factors and mobile genetic elements. The results of our studies will have significant impact in the search for novel approaches used to battle virulent and multiply resistant bacteria. We will continue studies of the extremely saline saltern environment. We will characterize the temperal dynamics of microbial composition fluctuations in salterns. Alterations in gene expression will be followed among halophilic microorganisms in response to temperature and salinity stres. Microorganisms from cave walls will be isolated in pure culture and their biotechnological potential characterized.
Significance for science
Our studies will contribute to the elucidation of the sources of pathogenic strains and genetic determinants of antibiotic resistance. Of particular interest is also to elucidate whether emergence of resistant bacteria depends only on selective pressures imposed by antimicrobial agents or might  changes in life style or introduction of bacteria from the environment also be involved. Although persisters were first described in 1944, the mechanisms involved in their formation have still not been elucidated. Two hypotheses stand out: (1) the SOS system, as part of the bacterial stress response, activates synthesis of the Tis toxin/antitoxin - tisB gene product which acts on the cell membrane to decrease the proton motive force and ATP levels, inducing a dormant state; and (2) the accumulation of indol, which acts as a signaling molecule during the stationary phase, triggers the synthesis of drug efflux proteins and proteins involved in the cell response to oxidative stress. Elucidation of persister formation will contribute to our knowledge of bacterial responses to environmental stress. The specific proteins found to be responsible for the formation of persisters, will be suitable targets for the development of much needed novel antimicrobial agents. Given the enormous flexibility and variability of bacteria, it is of great significance to study different model systems harboring several bacterial groups. This applies particularly to simple model systems that can be used to understand more complex systems such as the ocean. Thus, we expect that studies of salterns, as a model system, with emphasis on dynamics of establishment of microbial community structure, genome studies as well as studies of gene expression of saline microorganisms will contribute to elucidation of the mechanisms involved in bacterial evolution, bacterial adaptation to environmental perturbations and population genetics. Of particular significance is insight into the biotechnological potential of cave microbes which has been yet poorly investigated in Slovenia and elsewhere.
Significance for the country
The data obtained within the framework of this research will be of great significance for medical, veterinary and food-industry specialists, as our results will enable preparation of work guidelines for their fields of expertise (for example, risk assessment of the possible introduction of new virulent and multiple-resistant strains from the environment into hospitals). Utilization of antibiotics is no longer proportional to their effectiveness due to bacterial resistance and tolerance. Persisters may have been the main reason for the perseverance of chronic infections, mainly associated with hospitalization. Elucidation of their formation can enhance the efficiency of currently available antibiotics and expand the available targets in the search for new antimicrobial agents contributing to public health well being and the health care budget. The proposed research will proceed with broad international collaboration and transfer of knowledge between research institutions in Slovenia, Croatia and Spain. Groups with which we collaborate are foremost in their fields and such collaboration contributes to greater international recognition of Slovenia with integration of Slovene researchers into international research projects. At the same time the research collaborations will provide knowledge and use of techniques not yet established in Slovenia. As appropriate development of the microbial community is vital for optimal salt production the results of our investigations have significant potential for transfer to the technology of salt production. In view of the extent of Karst regions in Slovenia, as well as the pioneering role of Slovene scientists in Speleology, the development of the novel field of cave microbiology is of Slovene national interest.
Most important scientific results Annual report 2013, 2014, 2015, final report
Most important socioeconomically and culturally relevant results Annual report 2013, 2014, 2015, final report
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