A case of lung infection caused by an unusual strain of Nocardia farcinica.

A case of lung infection caused by an unusual strain of Nocardia farcinica is reported. This is the third case of the N. farcinica infection in this country. The strain failed to utilize rhamnose as sole carbon source, but could be identified by a numerical identification method. The mycolic acids contained 1-3 double bonds and the numbers of the carbon atoms of the mycolic acids were 50 to 60, average 56.