Differentiation of mycobacteria on the basis of chemotype profiles by using matrix solid-phase dispersion and thin-layer chromatography

Abstract

Because of the rising incidence of clinical mycobacterial infections and the difficulty in identification and characterization of mycobacteria at the subspecies and serovar levels, a technique for differentiation that could be performed quickly and with relatively little equipment and expense was developed. Lysis and fractionation of mycobacteria by matrix solid-phase dispersion followed by thin-layer chromatography were used to produce chemotype profiles of the lipid and glycolipid components of each isolate. Organisms tested included Mycobacterium scrofulaceum, Mycobacterium phlei, Mycobacterium smegmatis, Mycobacterium flavescens, Mycobacterium kansasii, Mycobacterium bovis, 11 isolates of Mycobacterium gordonae, 10 serovars of Mycobacterium avium, and four strains of Mycobacterium paratuberculosis. A relative retention (Rx) value was established for each visible band on the chromatographs by comparison with a band common to all organisms tested. The chemotype profiles produced were different for every separate species and serovar sampled. These findings suggest that matrix solid-phase dispersion and subsequent thin-layer chromatography may have the sensitivity and flexibility to characterize and identify mycobacteria at the species and subspecies levels and potentially to identify clinical isolates of mycobacteria that have been difficult to identify by standard means. The technique has certain advantages over current biochemical, immunologic, and genetic methods because it is relatively simple to perform, is inexpensive, and requires a small amount of bacterial sample.