Pyrolysis Mass Spectrometry: A New Method to Differentiate Between the Mycobacteria of the "Tuberculosis Complex" and Other Mycobacteria

Pyrolysis mass spectrometry (p.m.s.) was applied to differentiate 91 coded mycobacteria as belonging to either the 'tuberculosis complex' (M. tuberculosis, M. bovis and M. bovis BCG) or to other species of Mycobacterium. Strains were analysed in batches; in each batch three strains each of M. tuberculosis, M. bovis and M. bovis BCG were included as references. Mass spectra were evaluated by computerized multivariate analysis. A 92% positive correlation with classical identification tests was found (2.2% false negative, 5.5% false positive). Approaches for further improvement of this score are indicated. High speed and complete automation of sample analysis, as well as computerized data-processing, make p.m.s. a potential tool for routine application. Sample transfer from peripheral laboratories to a p.m.s. facility is easy, as samples can be sterilized before shipping.