Eur. Phys. J. Plus (2021) 136: 233
https://doi.org/10.1140/epjp/s13360-021-01152-1

Regular Article

Rapid detection of antibiotic sensitivity of Staphylococcus aureus by Raman tweezers

¹ Institute of Scientific Instruments of the Czech Academy of Sciences, v. v. i., Královopolská 147, 612 64, Brno, Czech Republic
² Department of Microbiology, Faculty of Medicine, Masaryk University and St. Anne’s Faculty Hospital, Pekařská 53, 656 91, Brno, Czech Republic

^a berns@isibrno.cz

Received: 17 November 2020
Accepted: 23 January 2021
Published online: 19 February 2021

Abstract

Methicillin-resistant Staphylococcus aureus is a bacterium pathogenic to humans and a leading cause of the hospital-acquired infections, causing significant increase in morbidity and mortality. Conventional antibiotic sensitivity testing requires culturing of the isolated pathogen in the presence of antibiotics, and it takes at least 48 hours. Comparatively faster determination of bacterial sensitivity to antibiotics can be achieved with Raman tweezers—an analytical method based on Raman spectroscopy and optical trapping. This article demonstrates the effectiveness of this approach for the discrimination between a methicillin-resistant and a methicillin-sensitive strain of Staphylococcus aureus in about 4 hours from a microliter volume of the bacterial sample. We found that the antibiotic-induced changes in the bacterial cells influenced the ratio of the Raman signals of nucleic acids to phenylalanine. This points to the antibiotic causing cell lysis and the associated loss of nucleic acids from the cytoplasm.