A real-time PCR assay for the detection of Neisseria gonorrhoeae in genital and extragenital specimens

Whiley, David M.; Buda, Philip P.; Freeman, Kate; Pattle, Neville; Bates, John; Sloots, Theo P.

doi:10.1016/j.diagmicrobio.2004.12.011

Cited by 29 publications

(31 citation statements)

References 14 publications

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“…other than N. gonorrhoeae as well (2,17,29). The pap assay that detects the porA pseudogene has reportedly a greater specificity for N. gonorrhoeae but slightly lower analytical sensitivity than the cppB assay (29,30). In this study, we compared the NsppID assay with these two previously published real-time PCR confirmatory assays; studies of real-time confirmatory assays based on a third target that is also used commercially for N. gonorrhoeae detection (the opa gene) were recently published but not included in this comparison (9,22,29,30).…”

Section: Discussionmentioning

confidence: 99%

Neisseria Species Identification Assay for the Confirmation of Neisseria gonorrhoeae -Positive Results of the COBAS Amplicor PCR

Mangold

Regner

Tajuddin³

et al. 2007

J Clin Microbiol

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Screening assays for Neisseria gonorrhoeae exhibit low positive predictive values, particularly in low-prevalence populations. A new real-time PCR assay that detects and identifies individual Neisseria spp. using melt curve analysis was compared to two previously published supplementary assays. NsppID, a 16S rRNA real-time PCR/melt curve assay developed to distinguish N. gonorrhoeae from other Neisseria spp., was compared to real-time PCR assays targeting genes reportedly specific for N. gonorrhoeae, the cppB gene and the porA pseudogene. A total of 408 clinical specimens (324 female endocervical swabs and 84 male urine or urogenital swab specimens) were screened using the COBAS Amplicor assay for Chlamydia trachomatis and N. gonorrhoeae (CT/NG) (Roche Diagnostics, Indianapolis, IN) followed by confirmatory testing via real-time PCR. The NsppID assay detected Neisseria spp. in 150/181 COBAS-positive specimens (82%), including six dual infections, and identified N. gonorrhoeae in 102 (56%) specimens. Sixty-nine of 181 (38%) specimens were positive for N. gonorrhoeae by porA pseudogene, and 115/181 (64%) were positive for cppB. However, cppB was also positive in 15% of COBAS-negative specimens, more than either NsppID (4%) or porA pseudogene (2%) assays. The porA pseudogene assay had the highest specificity for both genders but the lowest sensitivity, especially in female specimens. NsppID had a slightly lower specificity but greater sensitivity and overall accuracy. The least desirable confirmatory assay was cppB, due to poor specificity. The NsppID assay is an accurate confirmatory assay for N. gonorrhoeae detection. In addition, the NsppID assay can identify the non-N. gonorrhoeae species responsible for the majority of false-positive results from the COBAS Amplicor CT/NG assay.Neisseria gonorrhoeae is the second most prevalent sexually transmitted bacterium after Chlamydia trachomatis (4). Many N. gonorrhoeae infections are asymptomatic, especially in women, and if left untreated can develop long-term consequences, including chronic pelvic pain, pelvic inflammatory disease, and ascending infection of the fallopian tubes. Accurate diagnosis of symptomatic and asymptomatic infection is required to prevent these complications and to control the transmission of infection.Molecular assays such as the COBAS Amplicor CT/NG have high sensitivity and specificity in detecting both C. trachomatis and N. gonorrhoeae infections, and screening of high-prevalence populations results in positive predictive values (PPVs) of Ͼ80%. However, even with very specific assays, screening of low-prevalence populations lowers the positive predictive value of any test. For N. gonorrhoeae analysis of low-prevalence populations performed by the COBAS Amplicor CT/NG assay (6, 12, 32), unacceptable positive predictive values have been reported, particularly when the optical density (OD) reading is in the gray-zone of Ն0.2 to Ͻ3.5 (6). Repeat testing of the gray-zone and positive specimens has been shown to improve the specificity of the COBA...

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Section: Discussionmentioning

confidence: 99%

Neisseria Species Identification Assay for the Confirmation of Neisseria gonorrhoeae -Positive Results of the COBAS Amplicor PCR

Mangold

Regner

Tajuddin³

et al. 2007

J Clin Microbiol

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“…43,78,79 These results are supported by a more recent study using an N. gonorrhoeae porA pseudogene PCR assay. 80 The lower sensitivity of bacterial culture in the extragenital sites may be attributed to the heavy colonization of these sites by a broad range of other organisms, including other Neisseria species, which may interfere with N. gonorrhoeae isolation. 43 In general, pharyngeal and rectal gonorrhea are considered to be higher in MSM, and STDs are generally prevalent in these populations.…”

Section: Diagnosis Of Pharyngeal and Rectal Gonorrheamentioning

confidence: 99%

“…80,88,[101][102][103] With the exception of cppB gene-based assays, limited performance data are available for these in-house assays, with most only investigated in a single study. Briefly, Chaudhry et al 101 reported sensitivity, specificity, and positive predictive values of 100, 98.7, and 99.7%, respectively, using an ORF1-based PCR method on 489 urogenital specimens collected from an STD clinic in India.…”

Section: In-house Assaysmentioning

confidence: 99%

“…103 This assay was evaluated using 135 clinical samples and a panel of 173 microorganisms, including 73 nongonococcal Neisseria strains, and reported 100% sensitivity and specificity. Also, Whiley et al 80 investigated the use of the N. gonorrhoeae porA pseudogene as a target for a realtime PCR assay and reported 100% sensitivity and 100% specificity for 636 genital and extragenital specimens. This assay did not cross-react with the 102 commensal Neisseria strains tested.…”

Section: In-house Assaysmentioning

confidence: 99%

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Nucleic Acid Amplification Testing for Neisseria gonorrhoeae

Whiley

Tapsall

Sloots

2006

The Journal of Molecular Diagnostics

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178

163

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Nucleic acid amplification tests (NAATs) for the detection of Neisseria gonorrhoeae became available in the early 1990s. Although offering several advantages over traditional detection methods, N. gonorrhoeae NAATs do have some limitations. These include cost, risk of carryover contamination, inhibition, and inability to provide antibiotic resistance data. In addition, there are sequence-related limitations that are unique to N. gonorrhoeae NAATs. In particular, falsepositive results are a major consideration. These primarily stem from the frequent horizontal genetic exchange occurring within the Neisseria genus, leading to commensal Neisseria species acquiring N. gonorrhoeae genes. Furthermore, some N. gonorrhoeae subtypes may lack specific sequences targeted by a particular NAAT. Therefore, NAAT false-negative results because of sequence variation may occur in some gonococcal populations. Overall, the N. gonorrhoeae species continues to present a considerable challenge for molecular diagnostics. The need to evaluate N. gonorrhoeae NAATs before their use in any new patient population and to educate physicians on the limitations of these tests is emphasized in this review.

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“…Nucleic acid amplification testing (NAAT) has demonstrated efficacy in the detection of Chlamydia trachomatis and Neisseria gonorrhoeae from extraurogenital sources, including the rectum (12)(13)(14)(15)(16) and oropharynx (13)(14)(15)(16)(17)(18). A number of studies have reported increased pharyngeal and rectal detection rates of these agents via TMA compared to DNA-based amplification modalities (12,(14)(15)(16)18).…”

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confidence: 99%

Retrospective Assessment of Transcription-Mediated Amplification-Based Screening for Trichomonas vaginalis in Male Sexually Transmitted Infection Clinic Patients

Munson

Wenten²,

Phipps³

et al. 2013

J Clin Microbiol

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Transcription-mediated amplification (TMA) enhances detection of Neisseria gonorrhoeae and Chlamydia trachomatis from rectal and pharyngeal sources. The utility of TMA for detection of Trichomonas vaginalis has recently been described. We report on the performance of TMA for detection of sexually transmitted infection (STI) agents from extraurogenital sources, with a focus on T. vaginalis. Within a 21-month interval, 1,314 consecutive male patient encounters at an STI clinic resulted in collection of 2,408 specimens for C. trachomatis, N. gonorrhoeae, and T. vaginalis TMA screening. A total of 471 encounters were managed with a single specimen collection (94.9% urine), with 12.7% positive for at least one STI agent. This detection percentage increased to 14.4% with collection of specimens from two sources and to 20.3% with collection from three sources (P ‫؍‬ 0.03 versus single-source sampling). A total of 44.4% of encounters were managed by collection of urine and pharyngeal specimens and 19.1% by the addition of a third (rectal) collection. While procurement of urine and rectal specimens resulted in greater detection of C. trachomatis (6.1% and 11.3% rates, respectively) than of other STI agents, 858 pharyngeal specimens yielded a 2.9% T. vaginalis detection rate compared with 2.1% for N. gonorrhoeae and 1.6% for C. trachomatis. All T. vaginalis pharyngeal detections were confirmed by TMA-based alternative target testing. A total of 38.1% of T. vaginalis-positive pharyngeal specimens were derived from symptomatic patient encounters. A total of 85.7% of males with T. vaginalis-positive pharyngeal collections indicated strictly heterosexual preference. Additional specimen source sampling is necessary to make STI screening comprehensive. Incorporation of extraurogenital sources into assessment for T. vaginalis detection may identify additional symptomatic and asymptomatic male STI carriers.

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A real-time PCR assay for the detection of Neisseria gonorrhoeae in genital and extragenital specimens

Cited by 29 publications

References 14 publications

Neisseria Species Identification Assay for the Confirmation of Neisseria gonorrhoeae -Positive Results of the COBAS Amplicor PCR

Neisseria Species Identification Assay for the Confirmation of Neisseria gonorrhoeae -Positive Results of the COBAS Amplicor PCR

Nucleic Acid Amplification Testing for Neisseria gonorrhoeae

Retrospective Assessment of Transcription-Mediated Amplification-Based Screening for Trichomonas vaginalis in Male Sexually Transmitted Infection Clinic Patients

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