Vitek2 ms system

Further testing of isolates was carried out at the Institute of Medical Microbiology and Infections Epidemiology, Leipzig University, Leipzig, Germany. Isolates were identified by matrix-assisted laser desorption/ionization time - off light (MALDI-TOF) Mass spectrometry using VITEK2 MS system (Biomerieux, France) and verified by specie specific enterococcal ddl PCR6 (link). MALDI TOF Mass spectrometry is a mass spectrometry based technology that offers accurate, rapid, and inexpensive identification of microorganisms. Briefly, bacterial colonies are removed from agar culture plates, mixed with an excess of UV-absorbing matrix, and dried on steel target plates. The dried preparations are exposed to laser pulses, resulting in energy transfer from the matrix to the nonvolatile analyte molecules, with desorption of analyte into the gas phase. The ionized molecules are accelerated by electric potentials through a flight tube to the mass spectrometer, with separation of the biomarkers determined by their mass/charge ratio. The profile of biomarkers is then compared with profiles of a collection of well characterized organisms7 . vanC genotype was determined by identification of organisms as E. gallinarum and E. casseliflavus since these species express the vanC genotype constitutively.