Laboratory of Bacterial Genetics
RNDr. Irena Lichá, CSc.
Phone: +420 221 951 714, +420 221 951 747
The Laboratory of Bacterial Genetics is the youngest research group of the Department of Genetics and Microbiology (it was founded in 2010 as a detachment from the Laboratory of Bacterial Physiology). It mainly deals with the study of mechanisms that enable the soil bacteria to cope with various stressors, allowing them to survive in their natural environment. These bacteria are able to cope very well with rapidly changing environmental conditions, whether they are e.g. changes of temperature during the day and night or changes in osmolarity during drying and irrigating process of the soil. Moreover, there is constantly a struggle for territory and food sources among them. The bacteria are able to adapt to these conditions, changing not only the overall life strategy connected with the "switching on" and "shutting down" the expression of certain genes, but also by disposition to "re-arm", i.e. alter their genes.
Regarding the research on the action of various physical factors on bacterial cells in the Laboratory, the molecular nature of general stress response regulation is primarily studied in the model soil bacterium Bacillus subtilis. During their research, the members of the Laboratory use a variety of molecular genetic approaches, monitoring the changes in the expression profiles of genes responsible for stress adaptation (Petrovová et al., 2014). According to recent studies, the triggering of stress responses does not occur across the whole cell population, but is activated only stochastically in subpopulations; therefore, the research of the Laboratory starts with the study of the expression of genes in subpopulations using techniques such as flow cytometry and fluorescence microscopy with time-lapse observation.
Another research topic which is currently dealt with in the Laboratory of Bacterial Genetics is the study of bacterial persistence, i.e. the ability of bacteria to survive an antibiotic treatment without genetically determined resistance to a given antibiotic. This phenomenon is closely associated with stress adaptation and the stochastic character of its induction, but it is also an important phenomenon that complicates the treatment of chronic diseases. We study this phenomenon on the bacterium Staphylococcus aureus, which is phylogenetically related to a model bacterium Bacillus subtilis, and is also an important opportunistic pathogen causing chronic infections in immunosuppressed patients.
A further research topic of the Laboratory is the study of the ability of bacteria to adapt to chemical contaminants in the soil arising from various human activities. This problem is closely related to the major problem of today, which is the introduction of antibiotics into the soil, causing the subsequent selection of resistant potential pathogens. We monitor the abilities of the bacteria belonging to the Stenotrophomonas genus to spread the various determinants of antibiotic resistance to other species of bacteria.
PUsing bioinformatic methods, we also succeeded in demonstrating a direct relationship between the REP (Repetitive Extragenic Palindromes) elements and the newly-discovered tyrosine type of bacterial transposases (including the presence of these elements depending on the presence of tyrosine transposase in the particular genome), as well as to significantly expand our knowledge of the taxonomic occurrence, structural diversity and characteristics of the REP elements (Nunvář et al., 2010) and the evolution of REP diversity (Nunvář et al. 2013). We have also developed a method that uses these patterns to specify the clonal characterization of bacterial strains which contain the REP elements (Nunvář et al. 2012). This research was performed as part of the "Centre of the Environmental Microbiology" project in the framework of the Centers of Basic Research funded by the Ministry of Education and Sport of the Czech Republic. Currently, the structure of tyrosine transposase it is studied in cooperation with the Laboratory of Biomolerular Recognition (Institute of Biotechnology, Czech Academy of Sciences).
During their research, the members of the Laboratory use a variety of molecular genetic approaches as well as a bioinformatics analysis of whole genomes and their sequencing (Nunvář et al. 2014).