Particle-based immunochemical separation of methicillin resistant Staphylococcus aureus with indirect electrochemical detection of labeling oligonucleotides

Early detection of antibiotic-resistant bacteria causing inflammation in patients is a key for an appropriate and timely treatment. Classical microbiological cultivation methods are time-consuming and therefore it is necessary to discover a quick and effective method. The method used in this study is based on a sandwich immunoreaction of bacteria with IgG immobilized on streptavidin-coated polystyrene superparamagnetic particles and MRSA-specific antibody immobilized on gold non-magnetic nanoparticles labeled with oligonucleotides, which were detected by square wave voltammetry in combination with the adsorptive transfer technique. The assay is suitable for selective detection of methicillin-resistant Staphylococcus aureus in samples even at a concentration of 2 x 10(4) CFU mL(-1). The method can be flexibly modified for any other bacteria, depending on the antibodies used.