Viability study of clinical bacterial strains by capillary electrophoresis and flow cytometry approaches

One of the challenges medicine faces is the constantly growing resistance of pathogens to various classes of antibiotics. In this study, we investigated the use of capillary electrophoresis (CE) to characterize and assess the physiological states of three clinical bacterial strains-methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA), and Escherichia coli extended-spectrum β-lactamases (ESβL)-exposed to different antibiotics. All chosen bacteria are the leading causes of healthcare-associated and hospital-acquired invasive infections in adults. In the first part of the research, it was determined the optimal incubation time of the tested strains with antibiotics, represented as an optimal time of 24 h. In the second part, we have compared two approaches: flow cytometry (FC) as a standard method and CE as a proposed alternative approach. The viability of clinical strains treated with different class antibiotics calculated in CE measurements was strongly correlated (>0.83 for MSSA, >0.92 for ESβL and MRSA) with the viability obtained on the basis of FC measurements. As a result, CE has a chance to become a modern diagnostic method used in clinical practice. The CE cutoff was found to be 50%; above this value, the strain shows resistance to the action of the antibiotic.