Evaluation of four methods for isolation of Neisseria gonorrhoeae.

Bio-Bag (Marion Laboratories, Kansas City, Mo.) type C is made up of a ziplock plastic bag which contains a Thayer-Martin plate and a crushable CO2-generating ampoule. This system was compared with the candle extinction jar, Gono-Pak (Nasco, Fort Atkinson, Wis.), and JEMBEC (GIBCO Diagnostics, Lawrence, Mass.) systems to determine their efficiency and reliability for the isolation of Neisseria gonorrhoeae. A total of 191 anal and 130 urethral specimens were tested. There were 104 isolates of N. gonorrhoeae (24 anal and 80 urethral). The candle jar and Bio-Bag systems each detected 98 (94%) of the isolates. The Gono-Pak and JEMBEC systems detected 102 (98%) and 100 (96%) of the 104 isolates, respectively. These differences are not statistically significant. The Bio-Bag has the advantage of immediate CO2 release as compared with the Gono-Pak and JEMBEC systems, where CO2 production is dependent on the release of moisture from the medium. The Bio-Bag is a useful system, especially in situations where it is not convenient to use a candle jar.