Isoelectric focusing studies on Mycobacterium chelonei.

Analytical IEF has been used to give a direct visual comparison of beta-lactamases, down to extremely low levels, from very crude intracellular preparations. Identity and non-identity of strains could be proved by the pattern of bands produced by their beta-lactamases. Mycobacterial species gave a variety of beta-lactamase patterns. Identity was established between some strains of M. chelonei. IEF distinguished between enzymes within both the chelonei and abscessus sub-species that could not be differentiated by other methods. This technique could provide a means of identifying the source of a M. chelonei infection.