Biogenic Synthesis of Glycerol Tributyrate: A Selective Synergistic Agent Against Carbapenem-Resistant Klebsiella Pneumoniae
Abstract
The treatment of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant challenge in healthcare, with existing antibiotics often proving ineffective. In this study, we present a comprehensive biogenic route of synthesis method for glycerol tributyrate that can synergistically slow down the growth of CRKP with beta-lactam antibiotics. The synthesis of glycerol tributyrate was carried out using lipase mediated biogenic methods in a controlled laboratory setting. Characterization of the compound was performed using 1HNMR and MALDI-TOF-mass spectrometry techniques to confirm its structure and purity. Antibacterial activity was assessed by testing the compound against CRKP and Proteus vulgaris, with membrane potential measurements conducted to evaluate the effect on the bacteria. In silico docking study was performed with outer membrane protein A (OmpA) validated to altering membrane potential. The synthesized glycerol tributyrate demonstrated successful inhibition of CRKP when used in combination with beta-lactam antibiotics. Notably, the compound did not exhibit antibacterial activity against P. vulgaris. Membrane potential measurements revealed a substantial decrease with time in CRKP after treatment in comparison to P. vulgaris. Further analysis showed that the complex exhibited a strong binding affinity to outer membrane protein A (OmpA) of K. pneumoniae (-6.0 kcal/mol) compared to P. vulgaris (-4.9 kcal/mol). The obtained results demonstrated ineffectual behaviour against P. vulgaris but excellent effectiveness against K. pneumoniae which might be attributed the drop of membrane potential and higher binding affinity to OmpA in CRKP. Thus, the synthesized glycerol tributyrate leads to the blockage of porin channels, disrupting ion exchange with the external environment, preventing the uptake of essential nutrients for cell metabolism in CRKP and ultimately cell death.