Real-time PCR assay may be used to verify suspicious test results of Ureaplasmas spp. from the liquid culture method

Abstract

Ureaplasma spp. are associated with female genital tract infections and are mainly tested by liquid culture in developing countries. To evaluate the accuracy of liquid culture, 686 vaginal swabs were collected and tested by using the Mycoplasma Culturing, Identification, Enumeration, and Susceptibility (IES) Kit. Then these culture broths were verified using real-time PCR. Among 368 Ureaplasma positive broths, 263 contained Ureaplasma parvum, 30 contained Ureaplasma urealyticum, 57 contained both, and 18 were negative by real-time PCR. In 318 Ureaplasmas negative broths, 78 were found to be Ureaplasma positive by real-time PCR. Using real-time PCR as the reference, the false positive rate of the liquid culture was 7.0%. It has been suggested that the liquid culture positive broth should be inoculated onto solid agar to eliminate false-positives. However, solid culture is rarely used due to low sensitivity and being time consuming. Real-time PCR may be performed to replace solid culture to verify suspicious liquid culture results.