Diagnosis of Gonorrhea Using a Genetic Transformation Test on Mailed Clinical Specimens

Abstract

The genetic transformation test (GTT), a technique used for the detection of gonococcal DNA in clinical specimens, was compared with culture testing for the diagnosis of gonorrhea. At the De Kalb County Venereal Disease Clinic, Decatur, Ga., 454 cervical and 160 rectal specimens from women and 191 urethral specimens from men were collected in duplicate. One of each of the two specimens from each anatomic site was immediately plated on Martin-Lewis medium and incubated; the other specimen was mailed to Philadelphia for a GTT. Using culture results as a standard, the GTT had a specificity of 98.1% although some "false-positive" GTT results were probably a reflection of false-negative culture results. The sensitivity of the GTT was greater than 96% except when specimens were collected with Culturettes (Marion Laboratories, Kansas City, Mo.). In situations where Gram staining is not appropriate or where on-site culture facilities are not available, GTT may be the method of choice for the diagnosis of gonorrhea.

Duration of Persistence of Gonococcal DNA Detected by Ligase Chain Reaction in Men and Women following Recommended Therapy for Uncomplicated Gonorrhea

“…Urethral specimens (men) or cervical swab specimens (women) were collected for testing for gonorrhea by culture on Thayer-Martin agar or Gonostat (Sierra Diagnostics, Sonora, Calif.) and for testing for C. trachomatis by cell culture techniques. Cultures for N. gonorrhoeae and C. trachomatis and Gonostat testing were performed as described previously (9,10,13). Patients were then asked to submit either a urine specimen alone (men) or a urine specimen plus a self-obtained vaginal swab specimen (women) for testing for N. gonorrhoeae by LCR at the initial visit and each day during the study period.…”

Methods, Reagents and Media New Technology in Clinical Microbiology

“…If transformation occurs due to the presence of wild-type DNA the mutant strain will grow at 37°C. A field test of this method was described by Jaffe et al 6 Two other exciting reports describing the use of molecular biology techniques to analyze clinical micro-biology problems point to the future developments in the field. Falkow's group described the identification of enterotoxigenic Escherichia coli by colony hybridization using enterotoxin gene probes.…”