Role of Membrane Architecture in Development of Sensitivity to Cephalosporin Group of Antibiotics

Abstract

Due to efficient adaptation process the spread of resistance among microbial pathogens is always a major problem to therapy. The resistance towards an antibiotic can be either biochemical or genetic. The molecular orientation of bacterial cell wall is responsible in determining drug resistance. The role of cephalosporins for e.g.: ceftriaxone & cefazolin was studied in relation to its toxicity to B. subtilis (Gram positive) & E. coli (Gram negative).In the presence of cefazolin an abnormally high level of protein release was observed when intact cells as well as membrane vesicles. In the presence of cefazolin protein release was observed to been enhanced in contrast to ceftriaxone. The protein export in case of intact bacterial cells was higher than membrane vesicles suggesting the involvement of membrane proteins in drug sensitivity/resistance. The extent of protein released was also found to be modulated when both the cells were subjected to temperature treatment. However, maximum protein export was seen when gram positive& gram-negative cells were subjected to EDTA concentrations. In contrast availability of Mg²⁺ ions in the medium resulted in slight fall in protein release indicating stabilization of membrane vesicles as well as bacterial cell wall, which might have resulted in lowered protein export due to involvement of transport system. From this study it can be concluded that outer membrane orientation determines the therapeutic value of cefazolin & ceftriaxone.

Keywords: Ceftriaxone sodium, Cefazolin sodium, Ethylene diamine tetra acetate, Proton motive force, Minimum Inhibitory Concentration