Characterization of Micrococcus strains isolated from indoor air

The characterization of microbes, such as opportunists and pathogens (e.g., methicillin resistant Staphylococcus aureus [MRSA]), in indoor air is important for understanding disease transmission from person-to-person. Common genera found in the human skin microbiome include Micrococcus and Staphylococcus, but there only a limited number of tests to differentiate these genera and/or species. Both genera are believed to be released into indoor air from the shedding of human skin and are morphologically difficult to distinguish. In the current work, after the extraction of proteins from micrococci and the separation of these proteins on one dimensional electrophoretic gels, tryptic peptides were analyzed by MALDI TOF MS and the mass profiles compared with those of a reference strain (ATCC 4698). The results confirmed that all strains were consistent in identity with Micrococcus luteus.