Synergistic interaction of polymyxin B with carvacrol: antimicrobial strategy against polymyxin-resistant Klebsiella pneumoniae.

ABSTRACT

Objective: The antimicrobial activities of the synergistic combination of carvacrol and polymyxin B against polymyxin-resistant Klebsiella pneumoniae were evaluated. Methods: The methods employed checkerboard assays to investigate synergism, biofilm inhibition assessment and membrane integrity assay. In addition, the study included in vivo evaluation using a mouse infection model. Results: The checkerboard method evaluated 48 combinations, with 23 indicating synergistic action. Among these, carvacrol 10 mg/kg plus polymyxin B 2 mg/kg exhibited in vivo antimicrobial activity in a mouse model of infection, resulting in increased survival and a significant decrease in bacterial load in the blood. Conclusion: Polymyxin in synergy with carvacrol represents a promising alternative to be explored in the development of new antimicrobials.

In this study, we wanted to find a new way to fight a bacteria called Klebsiella pneumoniae, which is not easily killed by medication. We mixed two drugs, carvacrol and polymyxin B, to see if they would work together to fight the bacteria. We found that the mixed treatment helped to kill the bacteria. We also tried this mixed treatment in sick mice, and they got better. Our study shows that this mixed treatment might be a new way to fight bacteria that are hard to kill with regular drugs. Next, we hope to learn more about how it works.