The isolation of Neisseria gonorrhoeae: a comparison of three culture transport systems.

Endocervical swabs for the culture of Neisseria gonorrhoeae from 417 patients attending a pelvic infections clinic were evaluated. Three swabs were obtained from each patient. One swab was plated directly onto Thayer-Martin medium and taken shortly thereafter to a microbiology laboratory for evaluation. A second swab was inoculated into modified Stuart's transport media and transported soon afterward to the hospital microbiology laboratory. The third specimen was plated onto Transgrow media and transferred according to routine transportation protocols to the Maryland State Health Department for evaluation. The prevalence of Neisseria gonorrhoeae infection in this population was 14.6% (61/417). The sensitivities of the direct plating and modified Stuart's systems with on-site evaluation were 87% (53/61) and 85% (51/61), respectively, while the sensitivity of Transgrow plating with off-site evaluation was only 64% (39/61). These findings argue against the use of a system of Transgrow plating and off-site processing of culture specimens to screen for infections with Neisseria gonorrhoeae.