INFLUENCE OF ADAMANTANE DERIVATIVE KVM-97 ON cidA GENE EXPRESSION IN STAPHYLOCOCCUS AUREUS
Hrynchuk N1, Boiko I1, Vrynchanu N1, Zelena L2, Ishchenko L3, Korotkij Yu.4
1SI «Institute of Pharmacology and Toxicology of the NAMS of Ukraine»
2D.K. Zabolotny Institute of Microbiology and Virology of the NAS of Ukraine
3Ukrainian Laboratory of Quality and Safety of Agricultural Products, National University of
Life and Environmental Sciences of Ukraine
4Institute of organic chemistry of NAS of Ukraine
Introduction. Biofilm formation is the preferred lifestyle for many microorganisms, including human bacterial and fungal pathogens (Santos ALSD et al., 2018). Biofilm bacteria are enclosed in a self-produced extracellular matrix composed of extracellular DNA (eDNA), proteins, lipids and exopolysaccharides. Extracellular DNA (eDNA) is a key structural component of biofilms that protects resident bacteria from the host’s immune system and antimicrobial agents. DNA is adsorbed on the cell surface and spreads away from it, promoting adhesion to abiotic surfaces due to acid-base interactions. Cell lysis and eDNA release are regulated by the cidA gene. Inhibition of cidA expression reduces the ability of Staphylococcus aureus to form biofilms in vitro and in vivo biofilm growth models (Kelly C. Rice et. Al., 2007).
The aim of the study was to determine the expression of gene that regulate the production of eDNA in S. aureus under the action of an adamantane derivative 1-[4-(1-adamantyl)phenoxy]-3-(N-benzyl,N-dimethylamino)-2-propanolchloride.
Materials and methods. In this study bacterial strain S. aureus 222, resistant to oxacillin, chloramphenicol, ciprofloxacin, erythromycin, tetracycline, tobramycin was used. A derivative of adamantane KVM-97, used in the experiments, was investigated in concentration 0.5 × minimum inhibitory concentration (MIC). The effect of the compound on expression of cidA gene was determined using real-time PCR. The relative gene expression level was
calculated with 2-ΔΔСt method (Livak K. J., Schmittgen T. D., 2001). The expression of 16S rRNA gene was considered as an internal control. The data obtained were compared by NewmanKeuls test (p<0.05) (program «StatSoft «Statistica 6.0»).
Results. In previous studies, it was found that the compound KVM-97 exhibits antimicrobial activity against planktonic cells of S. aureus 222 and biofilms (N.O. Vrynchanu, N.I. Hrynchuk et. al., 2021). The KVM-97 treatment at a concentration of 0.5 MIC led to the considerable inhibition of the expression of cidA gene. The quantitative real-time PCR experiments demonstrated that the transcriptional activity of cidA gene was 7-fold less in S. aureus exposed to KVM-97 relative to control (p<0.05).
Conclusions. The obtained data suggest that adamantane derivative KVM-97 exhibited anti-biofilm activity and reduced transcriptional activity of cidA gene in S. aureus 222 at subinhibitory concentration.