Differentiation of Salmonella serotypes by pyrolysis-gas-liquid chromatography of cell fragments

Abstract

Pyrolysis-gas-liquid chromatography (PGLC) of whole cells and cell fragments was used to differentiate 10 Salmonella serotypes. Lyophilized samples (200 μg) of whole cells, cell walls, flagella, and deoxyribonucleic acid from each serotype were analyzed in duplicate by PGLC. Pyrochromatograms recorded as pyrolytic elution patterns represented thermal fragmentation products of the samples. Mathematical expressions of percent similarity and percent conformity were calculated for all possible pair combinations of the 10 serotypes. Stepwise discrminant analysis of the PGLC data showed that 100% correct classification of the 10 serotypes was possible from the flagella or deoxyribonucleic acid pyrochromatograms. The classification matrix of the whole-cell data showed a 90% correct classification. PGLC of cell fragments may provide useful information for taxonomic studies of Salmonella and other microorganisms.