Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by ligase chain reaction-based assays with clinical specimens from various sites: implications for diagnostic testing and screening

Abstract

Ligase chain reaction (LCR)-based tests for the diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae infections in men and women attending a sexually transmitted disease clinic were evaluated. LCR testing of urethral swab and urine specimens from men and cervical swab and urine specimens from women was compared with culture of male urethral swabs and female cervical and urethral swabs, respectively. An expanded "gold standard" was defined as a positive culture or at least one specimen confirmed to be positive by LCR testing. The prevalence of C. trachomatis infection as detected by cell culture was 7.0% among 614 men and 5.0% among 602 women. By LCR, these values increased to 11.4 and 9.9% with urethral swabs and urine, respectively, for men and 9.6 and 9.1% with cervical swabs and urine, respectively, for women. Relative to the expanded gold standard, the sensitivity of cell culture with male urethral swabs or female cervical swabs was 57.3 and 45.5%, respectively, compared with corresponding values of 93.3 and 87.9% for LCR. The sensitivity of LCR with urine specimens was 77.3 and 78.8% for men and women, respectively. The prevalence of N. gonorrhoeae infection as detected by culture was 5.9% among 220 men and 2.9% among 383 women. The corresponding values were 8.2 and 5.5%, respectively, by LCR testing of swabs. Prevalence values by LCR testing of urine were 7.3% for men and 2.9% for women. The sensitivity of culture was 72.2% for men and 50.0% for women. The sensitivities of LCR were 100% with male urethral swabs, 95.4% with female cervical swabs, 88.9% with male urine, and 50.0% with female urine. These results indicate that the LCR-based assays represent a major improvement in C. trachomatis and N. gonorrhoeae diagnostics. The sensitivity of testing of urethral or cervical swabs by LCR was markedly greater than that by culture. The sensitivity of testing female or male urine specimens was equal to or greater than that of culturing cervical or urethral specimens. LCR testing of urine specimens may prove useful for screening for C. trachomatis.

Discrete Proportional Hazards Models for Mismeasured Outcomes

“…As part of the study protocol, endocervical swab specimens were taken monthly, and were cultured to test for Neisseria gonorrhoeae. While specificity of culture is very high, the sensitivity of testing for Neisseria gonorrhoeae by culture relative to a gold standard of ligase chain reaction (LCR) has been estimated to be between 50% (Buimer et al, 1996) and 58.3% (Carroll et al, 1998). We applied the APH method to these data setting the sensitivity and specificity, respectively, at 55% and 100%.…”

Advances in ligase chain reaction and ligation-based amplifications for genotyping assays: Detection and applications

“…Detection of Neisseria gonorrhoeae [120][121][122][123][124][125]. Traditional detection methods were time consuming with a minimum of 24 h. LCR provided a rapid and effective diagnostic approach which is essential for disease control [120].…”

“…Traditional detection methods were time consuming with a minimum of 24 h. LCR provided a rapid and effective diagnostic approach which is essential for disease control [120]. LCR has been used for diagnosis of Chlamydia trachomatis infection [123][124][125][126][127] [130]. Mycobacterium tuberculosis complex was detected by LCR directly in clinical specimens [131].…”

“…It is robust with high capability for high-throughput applications and has been commercialized by Abbott Diagnostics company as Abbott LCx 1 which was FDA approved since 1994 [62,63]. It has been widely applied for detection of various microorganisms such as Mycobacterium tuberculosis, Chlamydia trachomatis and Neisseria gonorrhea [49,[120][121][122][123][124][125][126][127]131]. The main disadvantage for this version is that it is not suitable for multiplexing applications due to false positive results obtained and therefore it was taken off the market in 2002 [63].…”

The use of a genetic amplification technique (LCx MTB) to diagnose extrapulmonary tuberculosis

“…The use of DNA amplification methods for the detection of Mycobacter-ium tuberculosis in respiratory samples has yielded encouraging results, even in children [24], but there is little reported experience with clinical samples other than sputum. The LCx MTB system h m Abbott Diagnostic, Chicago, Il, USA, is based on the ligase chain reaction to detect DNA and has already been used to i d e e various microorganisms, including M. tuberculosis, h m sputum [7][8][9][10]. The amplified hgment corresponds to the gene encoding the b antigen (38-kDa protein), specific for M. tuberculosis [ll].…”