Summary: introduction

Few simple and reliable tests are available for the differentiation of Mycobacterium, Nocardia and related taxa. There is some evidence to indicate that chemical markers will be useful for the identification of such actinomycetes (Goodfellow, 1973; Staneck & Roberts, 1974).

Lipids characteristic of nocardiae (LCN-As) can be detected by thin-layer chromatographic analysis of ethanol-diethyl ether (I: I, v/v) extracts of nocardiae, true corynebacteria and rhodochrous strains, but are generally absent from mycobacteria, rothiae and actinomadurae (Mordarska, Mordarski & Goodfellow, 1972; Goodfellow, 1973; Goodfellow et al. 1974). LCN-As have been identified as free mycolic acids (Goodfellow et al. 1973) with the general structural formula

where r+s+t+u lies between o and 4, and m, n, 0, p and q are all greater than I (Maurice, Vacheron & Michel, 1971; Minnikin, Pate1 & Goodfellow, 1974). The mycolic acids frommycobacteria also contain components with oxygen functions, e.g. >C=O, CH-OCH, COOH, in addition to the 3-hydroxyacid unit (Etkmadi, 1967). Thin-layer chromatography (t.1.c.) of the methyl esters of the total mycolic acids from mycobacteria can therefore be expected to produce a multiple spot pattern, while those from strains classified in the other taxa should only form a single spot.

This paper demonstrates that the pattern of spots corresponding to mycolic esters obtained on t.1.c. analysis of whole-organism methanolysates provides a means of distinguishing mycobacteria and other taxa containing mycolic acids. The technique is rapid, simple, requires no expensive equipment, and should be applicable in routine clinical laboratories.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error