MICROBIAL PATHOGENESIS, cilt.196, ss.1-8, 2024 (SCI-Expanded)
Background: The increasing prevalence of antibiotic-resistant bacterial infections has led to the search for new
approaches.
Objective: This study aimed to evaluate the effects of carvacrol and N-acetyl cysteine, both individually and in
combination, on the planktonic cells and biofilm formations of Staphylococcus aureus, including methicillinresistant and methicillin-sensitive strains. Additionally, the study sought to perform cytotoxicity tests and
chemical characterization to further understand the properties and potential applications of these substances.
Methods: A total of 19 S. aureus strains were included in the study. Minimum inhibitory concentration and
minimum bactericidal concentration were determined by assays. Synergy analysis tests were carried out.
Cytotoxicity tests were conducted on the fibroblast cell line. Characterization test was performed.
Results: While Minimum inhibitory concentration and minimum bactericidal concentration values for carvacrol
varied between 250 and 500 μg/ml, these values were in the range of 32–64 mg/ml for N-acetyl cysteine. Biofilm
formation activities were identified. A total of eight strains, including six clinical and two standard strains with
the highest biofilm-forming ability, were selected for combination studies. The combination of Carvacrol and Nacetyl cysteine exhibited synergistic and partially synergistic effects on the tested planktonic and biofilm strains,
and these effects were dose-dependent. Carvacrol was found to be the most active drug at the end of 24, 48, and
72 h. Regarding the synergistic effect of N-acetyl cysteine + carvacrol, it was revealed to exhibit higher activity
than N-acetyl cysteine and lower activity than carvacrol.
Conclusion: The combination of carvacrol and N-acetyl cysteine demonstrated synergistic and partially synergistic
effects against both planktonic and biofilm forms of Staphylococcus aureus. These results suggest potential for
novel approaches in managing orthopedic infections, warranting further research to explore their therapeutic
applications.