A simplified hyaluronic acid based culture medium for mycobacteria isolated from human lepromata.

Acid-fast bacilli multiplied in liquid culture media containing hyaluronic acid when inoculated with mycobacteria from a lepromatous leprosy nodule. The culture was readily subcultured at ten day intervals in the homologue media, but failed to grow in the Dubos, Middlebrook and Lowenstein media. These findings confirm the results of Skinsnes et al (1975). Identification of this culture is not yet available, however it gives positive immunofluorescence with authentic anti-M. leprae serum. The obtained culture also grows as a chromogenic culture at 34 degrees C on a simple medium prepared from trypsin digested human umbilical cord, yeast extract powder and glycerol. This medium can be sterilized in an autoclave, but filter sterilized sheep, bovine or horse serum must be added aseptically as an essential ingredient. The medium does not differ considerably from the hyaluronic acid medium proposed by Skinsnes et al, but it is easier to prepare, it is inexpensive and permits a logarithmic growth within seven days of the so far unidentified culture isolated from leprotic nodules.