Antibacterial activity of Ionic Liquids based on ampicillin against resistant bacteria

Abstract

Antibacterial activities of novel Active Pharmaceutical Ingredient Ionic Liquids (API–ILs) based on ampicillin anion [Amp] have been evaluated. They showed growth inhibition and bactericidal properties on some sensitive bacteria and especially some Gram-negative resistant bacteria when compared to the [Na][Amp] and the initial bromide and chloride salts. For these studies were analysed the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBIC) against sensitive Gram-negative bacteria Escherichia coli ATCC 25922 and Klebsiella pneumoniae (clinically isolated), as well as sensitive Gram positive Staphylococcus Aureus ATCC 25923, Staphylococcus epidermidis and Enterococcus faecalis and completed using clinically isolated resistent strains such as E. coli TEM CTX M9, E. coli CTX M2 and E. coli AmpC MOX. From the obtained MIC values of studied API–ILs and standard [Na][Amp] were derived RDIC values (relative decrease of inhibitory concentration). High RDIC values of [C16Pyr][Amp] especially against two resistant Gram-negative strains E. coli TEM CTX M9 (RDIC >1000) and E. coli CTX M2 (RDIC >100) point clearly to a potential promising role of API–ILs as antimicrobial drugs in particular against resistant bacterial strains.