Staphylococci are a type of bacteria commonly found on the skin and hair of humans and mammals. They are usually harmless, however some strains, such as Staphylococcus aureus (S. aureus), can cause more serious infections if they are able to enter the body. The management of patients with bacterial infections relies on the early detection and identification of pathogens, as it enables the appropriate administration of antibiotics which saves lives. In the case of more serious conditions, such as sepsis, treatment should be started within an hour of the diagnosis. Unfortunately, current tests often take days to complete, putting lives at risk.
Dr. Ota Samek heads a Biophotonics and Optofluidics group at the Institute of Scientific Instruments within the Czech Academy of Sciences. The group has been using Raman spectroscopy to speed up the identification of bacterial infections and are hoping to introduce this method to hospitals as a tool for clinical diagnosis.
The team’s initial study focused on using Raman spectroscopy to identify staphylococci strains from bacterial colonies grown on an agar plate. Using a Renishaw inVia™ Raman microscope, the researchers acquired Raman spectra for 277 different staphylococcal strains and were able to differentiate between 16 species of staphylococci with almost 100% accuracy. This led to further research on the two most common infection-causing species of staphylococci – S. aureus and S. epidermidis. The team found that Raman spectroscopy techniques enabled them to rapidly and reliably distinguish between the strains.
The group’s success in identifying strains of staphylococci using Raman spectroscopy inspired further studies into whether the technique could also be used to investigate bacterial biofilms. Biofilms provide microorganisms with their own microenvironment that helps them survive within a host organism. They can be found on objects such as catheters, cannulas, artificial heart valves and even contact lenses. In this study, the team selected bacterium Staphylococcus epidermis and yeast Candida parapsilosis and used the inVia Raman microscope to distinguish between biofilm-positive- and biofilm-negative-strains directly from colonies grown on agar plates.
Dr. Samek has been using Renishaw Raman instruments to study staphylococci since 2007 when he spent two years at Swansea University, sponsored by a Marie-Curie Intra-European Fellowship. He noted the strong relationships between Renishaw and Swansea University and this encouraged him to connect with Renishaw on his return to the Czech Republic.
Published Papers on the Research
- K. Rebrosova, M. Siler, O. Samek, F. Ruzicka, S. Bernatova, V. Hola, J. Jezek, P. Zemanek, J. Sokolova, P. Petras: Rapid identification of staphylococci by Raman spectroscopy, Scientific Reports 7, 14846, 2017.
- K. Rebrosovsa, M. Siler, O. Samek, F. Ruzicka, S. Bernatova, J. Jezek, P. Zemanek, V. Hola: Differentiation between Staphylococcus aureus and Staphylococcus epidermidis strains using Raman spectroscopy, Future Microbiology 12, 881-890, 2017.
- K. Rebrošová, M. Šiler, O. Samek, F. Růžička, S. Bernatová, J. Ježek, P. Zemánek, V. Holá, Identification of ability to form biofilm in Candida parapsilosis and Staphylococcus epidermidis by Raman spectroscopy. Future Microbiology 14, 509–518, 2019