Marek Straka

Mr. Marek Straka

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
Verified
Journal Article
Open access
PDF file
AMAndrej Minich
Andrej Minich
Zdenko LevarskiZdenko Levarski
Zdenko Levarski
MMMária Mikulášová
Mária Mikulášová
MSMarek Straka
Marek Straka
Adriána LiptákováAdriána Liptáková
Adriána Liptáková
Stanislav StuchlíkStanislav Stuchlík
Stanislav Stuchlík
The presence of Staphylococcus epidermidis biofilms on medical devices is a major cause of nosocomial diseases and infections. Extensive research is directed at inhibiting the formation and maturation of such biofilms. Natural plant-derived phenolic compounds have promising antimicrobial effects against drug-resistant bacteria. The anti-biofilm activity of two selected phenolic compounds (vanillin and syringic acid) was tested against three biofilm-forming methicillin-resistant S. epidermidis strains with different genotypes. Resazurin assay combining crystal violet staining and confocal microscopy was used for biofilm and extracellular polymer substance (EPS) inhibition tests. Effects on EPS compounds such as proteins, extracellular DNA, and polysaccharides were also examined. Combined with quantitative real-time PCR of selected agr quorum-sensing systems and biofilm genetic determinants, our complex analysis of vanillin and syringic acid showed similar biofilm and EPS inhibition effects on S. epidermidis strains, reducing biofilm formation up to 80% and EPS up to 55%, depending on the genotype of the tested strain. Natural antimicrobial agents are thus potentially useful inhibitors of biofilms.

12 July 2021 in Viruses
Verified
Journal Article
Open access
PDF file
LSLivia Slobodnikova
Livia Slobodnikova
BMBarbora Markusková
Barbora Markusková
MKMichal Kajsik
Michal Kajsik
MAMichal Andrezál
Michal Andrezál
MSMarek Straka
Marek Straka
HDHana Drahovská
Hana Drahovská
Urinary tract infections (UTIs) are among the events that most frequently need medical intervention. Uropathogenic Escherichia coli are frequently their causative agents and the infections are sometimes complicated by the presence of polyresistant nosocomial strains. Phage therapy is a tool that has good prospects for the treatment of these infections. In the present study, we isolated and characterized two bacteriophages with broad host specificity against a panel of local uropathogenic E. coli strains and combined them into a phage cocktail. According to genome sequencing, these phages were closely related and belonged to the Tequatrovirus genus. The newly isolated phages showed very good activity on a panel of local clinical E. coli strains from urinary tract infections. In the form of a two-phage cocktail, they were active on E. coli strains belonging to phylogroups B2 and D, with relatively lower activity in B1 and no response in phylogroup A. Our study is a preliminary step toward the establishment of a national phage bank containing local, well-characterized phages with therapeutic potential for patients in Slovakia.

20 March 2020 in Molecules
Verified
Journal Article
Open access
PDF file
ETEva Trajčíková
Eva Trajčíková
EKElena Kurin
Elena Kurin
LSLivia Slobodnikova
Livia Slobodnikova
MSMarek Straka
Marek Straka
ALAneta Lichvariková
Aneta Lichvariková
Silvia Bittner FialováSilvia Bittner Fialová
Silvia Bittner Fialová
The compositions of leaf infusions of three genotypes of Lycopus europaeus L. with origins in central Europe, namely L. europaeus A (LeuA), L. europaeus B (LeuB), and L. europaeus C (LeuC), and one genotype of L. exaltatus (Lex), were examined by LC-MS-DAD (Liquid Chromatography Mass Spectrometry and Diode Array Detection) analysis. This revealed the presence of thirteen compounds belonging to the groups of phenolic acids and flavonoids, with a predominance of rosmarinic acid (RA) and luteolin-7-O-glucuronide (LGlr). The antimicrobial activity of leaf infusions was tested on the collection strains of Gram-positive and Gram-negative bacteria, and on the clinical Staphylococcus aureus strains. We detected higher activity against Gram-positive bacteria, of which the most susceptible strains were those of Staphylococcus aureus, including methicillin-resistant and poly-resistant strains. Furthermore, we examined the antioxidant activity of leaf infusions using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods, and on NIH/3T3 cell lines using dichlorodihydrofluorescein diacetate (DCFH-DA). We also studied the mutual interactions between selected infusions, namely RA and/or LGlr. In the mixtures of leaf infusion and RA or LGlr, we observed slight synergism and a high dose reduction index in most cases. This leads to the beneficial dose reduction at a given antioxidant effect level in mixtures compared to the doses of the parts used alone. Therefore, our study draws attention to further applications of the Lycopus leaves as a valuable alternative source of natural antioxidants and as a promising topical antibacterial agent for medicinal use.

6 July 2022 in Microorganisms
Verified
Journal Article
Open access
PDF file
MSMarek Straka
Marek Straka
MDMartina Dubinova
Martina Dubinova
Adriána LiptákováAdriána Liptáková
Adriána Liptáková
Treatment of infections caused by bacteria has become more complex due to the increasing number of bacterial strains that are resistant to conventional antimicrobial therapy. A highly promising alternative appears to be bacteriophage (phage) therapy, in which natural predators of bacteria, bacteriophages, play a role. Although these viruses were first discovered in 1917, the development of phage therapy was impacted by the discovery of antibiotics, which spread more quickly and effectively in medical practice. Despite this, phage therapy has a long history in Eastern Europe; however, Western countries are currently striving to reintroduce phage therapy as a tool in the fight against diseases caused by drug-resistant bacteria. This review describes phage biology, bacterial and phage competition mechanisms, and the benefits and drawbacks of phage therapy. The results of various laboratory experiments, and clinical cases where phage therapy was administered, are described.

Verified
Journal Article
Open access
PDF file
MSMarek Straka
Marek Straka
ZHZuzana Hubenáková
Zuzana Hubenáková
LJLucia Janošíková
Lucia Janošíková
ALAneta Lichvariková
Aneta Lichvariková
AMAndrej Minich
Andrej Minich
LSLivia Slobodnikova
Livia Slobodnikova
The treatment of infections caused by Staphylococcus aureus is currently complicated by the increasing number of strains resistant to antimicrobial agents. One promising way to solve this problem is phage therapy. Due to the lack of data on the effectiveness and safety of phage preparations, STAFAL® is the only registered phage preparation for the treatment of infectious diseases in the Slovak Republic and the entire European Union. The aim of this work was to determine the effectiveness of the STAFAL® phage preparation against S. aureus strains of different origins with variable sensitivity to antimicrobial substances and with different genetic backgrounds. For this purpose, 111 carrier strains, 35 clinical isolates from bloodstream infections, and 46 strains from skin and soft tissue infections were analysed. The effectiveness of STAFAL® was determined by the plaque forming method. STAFAL® was effective against 74.0% of the strains tested. Susceptibility to this phage preparation was significantly higher in strains resistant to methicillin (MRSA), erythromycin and clindamycin (p < 0.05). The high efficiency of the STAFAL® preparation was confirmed against spa types t003, t024 and t032, typical of the hospital environment. The in vitro results indicate high therapeutic potential of the STAFAL® antistaphylococcal phage preparation, especially against MRSA strains.

9 October 2026 in Bratislava Medical Journal
Verified
Journal Article
Open access
PDF file
MDMartina Dubinová
Martina Dubinová
MSMarek Straka
Marek Straka
ĽLĽudmila Lysá
Ľudmila Lysá
MHMartin Haas
Martin Haas
MPMarián Píš
Marián Píš
Adriána LiptákováAdriána Liptáková
Adriána Liptáková
The management of chronic wounds remains a major challenge in healthcare. Chronic wound infections are frequently associated with biofilm formation, which complicates accurate microbiological diagnosis and subsequent treatment. The diagnosis of wound infection relies predominantly on conventional wound swab sampling, a method with limited sensitivity. Consequently, alternative diagnostic approaches are being investigated. Ceramic dressings combined with sonication may represent a promising tool for improving the diagnosis of chronic wound infections. The present study evaluated the diagnostic and therapeutic potential of this approach. A total of 27 patients with 29 chronic wounds were enrolled. Commercially available ceramic dressings were applied to the wounds and subsequently subjected to sonication to recover causative microbial pathogens. Conventional wound swab sampling was performed in parallel for comparison. Wound status was assessed before and after treatment with the ceramic dressings. Ceramic dressings combined with sonication demonstrated significantly greater sensitivity for the detection of microbial pathogens than the conventional swab method (93.6% vs. 47.8%, p < 0.05). In addition, this approach identified significantly more antibiotic-resistant isolates than conventional swab sampling ( p < 0.05). Following treatment guided by microbiological findings obtained from ceramic dressing sonication and targeted antimicrobial therapy, significant improvements were observed across all evaluated clinical parameters of infected wounds. Complete wound healing was achieved in 18 of the 29 wounds (62.1%) in the monitored period. These findings support the incorporation of ceramic dressings combined with sonication into the diagnostic pathway for chronic wound infections and suggest that this approach may also contribute to improved therapeutic outcomes.