Effect of Adaptive Changes of Lysophosphatidylethanolamine Content on Ampicillin Resistance of Yersinia Pseudotuberculosis

Most antibiotics are targeted at intracellular processes. Therefore, their effects are determined by an ability to penetrate bacterial membranes. Mechanism of reducing permeability of porin channels in Gram-negative bacteria is the least known one among the possible reasons of antibiotic resistance. The adaptive accumulation of lysophosphatidylethanolamine (LPE), which is observed under conditions typical for the parasitic phase (in particular, the availability of glucose) of Gram-negative bacteria Yersinia pseudotuberculsis is accompanied by rearrangements in conformation of outer membrane protein OmpF that may impede the porin channel permeability for s-lactam antibiotics. In present study, we report that adaptive accumulation of LPE in membranes of Y. pseudotuberculosis grown in the presence of glucose reduces antibacterial effect of ampicillin. In turn, polyphenol extract from buckwheat husks (PEBH) induces both the decrease in the level of LPE and resistance of bacteria to ampicillin. Therefore, PEBH acts synergistically with ampicillin in vivo by lowering its MICs and therefore can be used as antibiotic adjuvant to improve an antibiotic's ability to cross the outer membrane. These results showed that strategies for regulation of adaptive changes in lipid matrix of bacterial membranes is a new potentially effective way to increase the sensitivity of pathogens to known antibiotics.