A Simple Medium for Identification and Maintenance of the Gonococcus and Other Bacteria

The media generally used for the cultivation of the gonococcus have certain disadvantages. Most of them are unable to maintain freshly isolated cultures in a viable state for more than a few days. They may require ingredients likely to be variable in quality (e.g., meat infusion) or not readily available (e.g., horse serum). Moreover, the incorporation of such materials as ascitic fluid (Carpenter, 1945; Mahoney, Van Slyke, Cutler, and Blum, 1946) or serum (Peizer, 1942) in fermentation media requires special procedures for sterilization or aseptic handling that may be difficult to manage in the small laboratory. The medium here described has none of these drawbacks. It is composed of available and relatively stable materials, can be sterilized in the autoclave, and supports continued growth of freshly isolated gonococci if transferred at intervals of 10 days, or even longer for many of the strains tested. In addition, it is a reliable base medium for the performance of fermentation tests. Its chief constituent is pancreatic casein digest, which has been shown (Vera, 1944) to be useful in the identification of clostridia.