Supplementary report on the case of chronic ulceration of the foot due to a new pathogenic mycobacterium (MacCallum).

The American boy of six and one-half years, the son of missionaries to the Belgian Congo, whose case was reported in a preliminary way by Dr. E. van Oye and Dr. M. Ballion (1), was brought back home to the United States and was referred to us because of our interest in surgical infections. Although we were told acid-fast organisms had been found in this lesion, it had some of the characteristics of the undermining burrowing ulcers which are not infrequently seen in this country. Our bacteriological studies revealed not only the acidfast organisms but hemolytic streptococci, hemolytic staphy. lococci and several different aerobic Gram-negative bacilli. In any bacterial mixture the significance of anyone species cannot be immediately determined. The treatment was therefore directed at first toward the hemolytic streptococcus and the hemolytic staphylococcus. Because of the severity and the duration of the infection, the boy was given the maximum dose of systemic bacitracin, namely, 400 units per kilogram of body weight, every eight hours. On this regime the hemolytic streptococcus and the Staphylococcus aureus disappeared from the wound and there was some immediate improvement in the appearance of the ulcer, but bacitracin had to be discontinued after six days because of early signs of nephrotoxicity. This rapidly cleared after stopping the drug, which proved to be from a toxic lot. Thereafter penicillin, streptomycin, aureomycin and chloromycetin were tried, both alone and in combination, but there was no real evidence of healing over a period of several weeks. The acid-fast organisms were still present in enormous numbers. The smears stained with the Ziehl-Neelsen