Lysozyme is an enzymatically stable 14-kda ...

New sample preparation method was developed for fresh, whole cells of gram-positive bacteria, which will be analyzed on a matrix with the assistance of laser desorption / ionization time-flight mass spectrometry (MALDI TOF MS). With fresh, tselnokletochnaya gram-negative bacteria of the family Enterobacteriaceae

, we previously achieved range, consisting of 50 vertices and mass range of 225 kDa. Since similar spectral quantity can not be achieved by gram-positive bacteria, using the same protocol, we investigated an alternative approach, focusing on a thick layer of peptidoglycan cell wall. Gram-positive bacteria incubated with 0. 050. 5 mg / mL lysozyme for 30 min before analyzed by MALDI TOF MS. Lysozyme is an enzymatically stable 14-kDa protein that specifically cleaves peptidoglycan between disaccharide units. A significant increase in the total number of peaks (50) to 214 kDa range observed without interference from the presence of lysozyme. We strattera dosing show that four different species (Staphylococcus aureus

,

S. haemolyticus,

Streptococcus pyogenes and S.

agalactiae) reproducible subset of peaks were found in the spectra of the reference strain and two independent clinical isolates. The data show that the preparation of samples may be useful to increase the total number of peaks in the spectra for the future development strategy of bacterial identification. .