Enhancement by lysozyme of the sensitivity of Treponema pallidum immobilization tests.

The addition of lysozyme to the survival medium has been shown (Metzger, Hardy, and Nell, 1961) to increase the rate of immobilization of Treponema pallidum by syphilitic serum and complement; this might allow T. pallidum immobilization (TPI) tests to be completed in a working day. But, more important from the point of view of diagnosis, was the possibility of increasing the sensitivity of the standard 18-hr TPI test and, perhaps also, of the already highly sensitive 40-hr test (Rosenau and Kent, 1958; Kent and DeWeerdt, 1961).