Observations on the ubiquity of the Mycobacterium tuberculosis sulfatides in mycobacteria

Recent publications claimed improved selective extraction and recovery of the sulfatides ("sulfolipids") from Mycobacterium tuberculosis, and alleged their distribution among "all mycobacteria." Our evidence denies the selectivity, suggests that some ubiquitous mycobacterial glycolipid was mistaken for sulfatide, and that its occurrence in saprophytic species has not yet been unequivocally demonstrated.