• Thymol/Cefotaxime Synergism as a Promising Antibacterial Strategy Against Resistant Escherichia coli Strains
  • Mehrsa Karim,1,* Mina Shirmohammadpour,2 Sajjad jafari,3 Bahman Mirzaei,4 Faeze Khanizade,5
    1. Department of Microbiology and Virology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
    2. Department of Microbiology and Virology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
    3. Department of Microbiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, West Azerbaijan, Iran
    4. Department of Microbiology and Virology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
    5. Department of Microbiology and Virology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran


  • Introduction: This study looked into the antibacterial synergism of the thymol/cefotaxime against Escherichia coli (E. coli) bacteria.
  • Methods: The MIC-MBC method was used to assess the antimicrobial effects of thymol and cefotaxime, separately and in combination at varying doses, against E. coli ATCC25922. Using the MIC-MBC method, the antibacterial activity of a compound that exhibited a synergistic effect on twenty clinical strains of E. coli bacteria was assessed. Additionally, the FTIR device was utilized to analyze the substance's molecular interactions, chemical bonds, and functional groups. The checkered technique, the time killing curve and biofilm inhibition on the E. coli ATCC25922 bacteria, the hemolysis method, the MTT method, and the hemolysis method were used to investigate the cytotoxicity on human skin fibroblast cells (Ffk), and red blood cells (RBCs). There was a synergistic impact from the A3 compound.
  • Results: The study's findings demonstrated that when applied to E. coli ATCC25922, the antimicrobial activities of thymol, cefotaxime, and thymol/cefotaxime (A3 compound) were, respectively, 256, 32, and 128/16 (FICI: 1 µg/ml). The A3 compound exhibited antibacterial activity of 1024-16/256-4 µg/ml on clinical strains of E. coli, respectively. Compared to the individual modes, the combined mode had a longer time curve for eliminating E. coli. These compounds had chemical bonds OH carbohydrates proteins, polyphenols, C=O amide I band, C-O-C polysaccharide, and C-N amide III band, but C=C conjugated, C≡C compound shows the connection between thymol/cefotaxime. Thymol, cefotaxime, and other chemicals have biofilm inhibition rates of 29.69%, 16.28%, and 39.28%, respectively, against E. coli bacteria. The toxicity of thymol, cefotaxime, and A3 compound against human RBCs were 36.12, 8.33, and 8.38, and against human Ffk cells were 19.66, 7.08, and 9.03 respectively.
  • Conclusion: The findings of this investigation demonstrated the strong antibacterial and anti-biofilm qualities of thymol/cefotaxime, even in light of cefotaxime's resistance to treating illnesses brought on by E. coli. This compound can be examined later, and their toxicity on several cells was the same.
  • Keywords: Escherichia coli, Thymol, Cefotaxime, Synergistic