Improved media for the culture of Neisseria gonorrhoeae.

MANY attempts have been made to devise liquid culture media that can support the growth of Neisseria gonorrhoeae. These media can be divided into two main categories: the chemically defined but complicated media such as NCDM (new chemically defined medium) (Kenny et al., 1967) and NEDF (new defined fluid medium) (Catlin, 1973), and the simpler liquid media such as ESP (enriched single phase) (Chan, Wiseman and Caird, 1975) and BP (biphasic) (Gerhardt and Heden, 1960) which are based on an early formulation for Bacto GC Medium Base. Some of the chemically defined media have produced excellent results but are much too complex for routine use. Conversely, most of the simpler media have failed to support vigorous growth of all strains of N. gonorrhoeae from small inocula. These problems seemed to have been overcome by Hafiz and McEntegart (1976) who devised a new medium (ANM), based on the GCBD solid medium (Difco GC base + supplements) of Kellog et al. (1963), and with which they obtained excellent results. However the performance of ANM in our laboratory was disappointing and some of the possible reasons for this were investigated. This has led to the development of a modified liquid medium (G77L) and a corresponding solid medium (G77S) which have given better results than other gonococcal media commonly used.