Purine analogue sensitivity and lipase activity of leptospires.

The genus Leptospira can be divided into three groups based on purine analogue sensitivity and lipase (trioleinase) activity. Group 1 contains members of the "parasitic complex" of leptospires which initially cannot grow in media containing 10 mug of 2,6-diaminopurine (DAP) per ml or 200 mug of 8-azaguanine per ml. In addition, leptospires in this group possess lipase activity. Group 2 also contains members of the "parasitic complex" of leptospires. Although these leptospires are similarly sensitive to 8-azaguanine, they differ from group 1 leptospires in that they grow in media containing 10 mug of DAP per ml, and they do not possess detectable lipase activity. Group 3 consists of leptospires belonging to the "biflexa complex." These leptospires are resistant to both purine analogues and have lipase activity.