An evaluation of New York City transport medium for the detection of Neisseria gonorrhoeae in clinical specimens.

New York City (NYC) transport medium was compared with Transgrow and Amies charcoal medium for the recovery of N. gonorrhoeae from clinical material. All three transport media were comparable within one day in transit. None of them consistently preserved N. gonorrhoeae for 3 days. However, for 2 days in transit NYC yielded 50% more gonococci than Transgrow and 22% more than Amies. It has been claimed that NYC transport medium does not require the addition of atmospheric CO2 for the preservation and growth of N. gonorrhoeae. We observed that the survival rate of N. gonorrhoeae on NYC transport medium was markedly improved by the presence of ambient CO2. It was found practical to transport specimens on 5 cm diameter petri plates containing NYC transport medium in sealed plastic bags with chemically generated CO2; such an environment was also suitable for incubation. Over 90% of N. gonorrhoeae present in clinical specimens survived for 48 h under these conditions. Petri plates are more practical to process for isolation and identification than medium sloped in screw-capped bottles as recommended for Transgrow.