Evaluation of the leptospiral protein-free medium.

Bey and Johnson's leptospiral protein-free medium is evaluated and some modifications to it are introduced. Different serovars have shown good growth in this medium, but generally it is necessary to adapt it before obtaining success. When adapted, the serovars, subcultured serially, have a long term survival, with a good bacterial density. Some serovars, such as tarassovi and grippotyphosa exhibited irregular results.