Metabolic fingerprinting of Staphylococcus aureus - A tool for characterization and epidemiological typing in bovine mastitis

GRUNERT T; DEUTSCH M; FRICKER M; WENNING M; SORDELLI DO; BUZZOLA FR; EHLING-SCHULTZ M

Lyon

Simposio; International Symposium on Staphylococcus and Staphylococcal Infections (ISSSI); 2012

. International Symposium on Staphylococcus and Staphylococcal Infections (ISSSI)

Staphylococcus aureus persistent and recurrent infections of the mammary gland are one of the major health problems in dairy cattle. Epidemiological studies on S. aureus occurrence in cattle herds suggest that certain strains are predominant, especially in case of subclinical mastitis. However, adaptation mechanism and properties of persisting strains are largely unknown and more data, especially from epidemiological studies, are needed to decipher the basis of S. aureus persistence in dairy cattle.  Most techniques for epidemiological typing rely on molecular-based methods, as for instance PFGE and MLST, which are highly discriminatory. However, the major drawback of these methods is that they are labour and cost intensive. Here we present a rapid and simple alternative method, based on metabolic fingerprinting by Fourier-transform infrared (FTIR) spectroscopy, for the monitoring of S. aureus in cows with recurrent or persistent udder infections. The entire biochemical composition of whole cells is recorded by the absorbance of mid-infrared light by the molecules present in the cells. Specific spectral windows can be assigned to particular cellular components, e.g. protein, carbohydrates and fatty acids. The generated spectral data can be classified using a variety of chemometric methods, like cluster and principal component analyses as well as supervised learning methods. Results from ongoing research will be reported and the potential and limits of FTIR spectroscopy for S. aureus characterisation and typing will be discussed.