The Primary Isolation ofMycobacterium ulcerans

The first reported primary isolation of Mycobacterium ulcerans in the United States is presented. The organism was recovered from an ulcer of a Peace Corps worker who spent some time in Nigeria. The specimen was muscle tissue which was ground, immediately inoculated into tubes containing Lowenstein-Jensen medium, and incubated at 37 C, 35 C, 33 C, and 22 C. Growth occurred 8 weeks later on the tubes incubated at 33 C. only. The organisms were acid-fast and were found to be peroxidase negative, catalase positive, and cytochrome neutral red very positive. The importance of inoculating a valid specimen directly onto Lowenstein-Jensen media and incubating at 33 C. is stressed.