Detection of externally induced impairments in single bacterial cells by laser microbe mass analysis.

Applying the laser microbe mass analyzer method (LAMMA), mass spectra (fingerprints) were taken from single bacterial cells not treated or treated with high temperature, X-irradiation, isonicotinic acid hydrazide (INH), or diaminodiphenylsulfone (DDS). Spectra of treated cells ("M. lufu," M. tuberculosis H37Ra, E. coli) differ from those of controls in that the K+/Na+ ratio was smaller and in that the intensities of peaks with m/e greater than 100 were lower. From the results with M. leprae the possible application of this new method for monitoring the effectiveness of leprosy therapy is proposed.