LCX NEISSERIA GONORRHOEAE ASSAY

K935833 · Abbott Laboratories · LSL · May 6, 1996 · Microbiology

Device Facts

• Record ID: K935833
• Device Name: LCX NEISSERIA GONORRHOEAE ASSAY
• Applicant: Abbott Laboratories
• Product Code: LSL · Microbiology
• Decision Date: May 6, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3390
• Device Class: Class 2

Intended Use

The LCx Neisseria gonorrhoeae Assay uses LCR™ (Ligase Chain Reaction) amplification technology in the LCx Probe System for the direct, qualitative detection of a specific target nucleic acid sequence in the Opa gene of Neisseria gonorrhoeae in female endocervical and male urethral swab specimens or in male and female urine specimens from symptomatic and asymptomatic males and females.

Device Story

The LCx Neisseria gonorrhoeae Assay utilizes Ligase Chain Reaction (LCR) amplification technology to detect specific target nucleic acid sequences within the Opa gene of N. gonorrhoeae. The device processes clinical specimens—specifically endocervical swabs, urethral swabs, and urine—to identify the presence of the pathogen. It serves as an in vitro diagnostic tool, providing qualitative results that assist clinicians in diagnosing gonococcal infections. By detecting DNA rather than relying on whole-organism culture, the assay offers an alternative diagnostic pathway for both symptomatic and asymptomatic patients. The system is designed for laboratory use, where it provides objective molecular evidence of infection, facilitating timely clinical decision-making and patient management.

Clinical Evidence

Clinical performance was evaluated at four U.S. sites comparing the LCx assay to culture. Data included both frozen and fresh specimens from symptomatic and asymptomatic patients. For frozen specimens, overall sensitivity was 89.4% (asymptomatic) and 98.8% (symptomatic), with specificities of 98.6% and 97.7%, respectively. For fresh specimens, sensitivity was 100% (asymptomatic) and 97.0% (symptomatic), with specificities of 98.6% and 98.7%. Analytical sensitivity was 10 CFU per reaction across 6 auxotrophs. Specificity was confirmed against 91 non-gonococcal organisms.

Technological Characteristics

Uses Ligase Chain Reaction (LCR) amplification technology. Targets the Opa gene of Neisseria gonorrhoeae. Analytical sensitivity is 10 CFU per reaction. Designed for use with the LCx Probe System.

Indications for Use

Indicated for the qualitative detection of Neisseria gonorrhoeae DNA in female endocervical swabs, male urethral swabs, and male/female urine specimens from both symptomatic and asymptomatic individuals.

Regulatory Classification

Identification

Neisseria spp. direct serological test reagents are devices that consist of antigens and antisera used in serological tests to identify Neisseria spp. from cultured isolates. Additionally, some of these reagents consist of Neisseria spp. antisera conjugated with a fluorescent dye (immunofluorescent reagents) which may be used to detect the presence of Neisseria spp. directly from clinical specimens. The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Neisseria, such as epidemic cerebrospinal meningitis, meningococcal disease, and gonorrhea, and also provides epidemiological information on diseases caused by these microorganisms. The device does not include products for the detection of gonorrhea in humans by indirect methods, such as detection of antibodies or of oxidase produced by gonococcal organisms.

Submission Summary (Full Text)

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K935833

510 (k) SUMMARY

MAY -6 1996

LCx® Neisseria gonorrhoeae Assay

SUMMARY OF SAFETY AND EFFECTIVENESS INFORMATION SUPPORTING A SUBSTANTIAL EQUIVALENCE DETERMINATION

The following information as presented in the Premarket Notification (510(k) for LCx Neisseria gonorrhoeae Assay) constitutes data supporting a substantially equivalent determination.

The LCx Neisseria gonorrhoeae Assay uses LCR™ (Ligase Chain Reaction) amplification technology in the LCx Probe System for the direct, qualitative detection of a specific target nucleic acid sequence in the Opa gene of Neisseria gonorrhoeae in female endocervical and male urethral swab specimens or in male and female urine specimens from symptomatic and asymptomatic males and females.

The LCx Neisseria gonorrhoeae Assay is substantially equivalent to the culture method.

The two methods are similar in that:

- Both assays detect the presence of N. gonorrhoeae.

- Both assays are in vitro tests.

The two methods differ in that:

- The LCx Neisseria gonorrhoeae Assay detects the DNA of N. gonorrhoeae organisms, while the culture method detects the whole organism.

- The LCx Neisseria gonorrhoeae Assay detects the DNA of N. gonorrhoeae in male and female urine.

In four U.S. sites, the performance characteristics of the LCx Neisseria gonorrhoeae Assay were determined by comparing assay results to results of culture for Neisseria gonorrhoeae. The overall results presented by specimen type and storage condition are shown in the table below.

Performance Summary Compared to Culture: Frozen Specimens

| Sample Type | Symptomatology | Total | LCx Culture | Pos Pos | Pos Neg | Neg Pos | Neg Neg | Sensitivity (95% C.I.) | Specificity (95% C.I.) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Female Endocervical | Asymptomatic | 623 | | 24 | 11 | 3 | 585 | 88.9% (24/27)
(70.8-97.6) | 98.2% (505/596)
(96.7-99.1) |
| | Symptomatic | 332 | | 47 | 8 | 0 | 277 | 100.0% (47/47)
(92.5-100.0) | 97.2% (277/205)
(94.5-98.8) |
| Female Urine | Asymptomatic | 140 | | 23 | 1 | 2 | 114 | 92.0% (23/25)
(74.0-99.0) | 99.1% (114/115)
(95.3-100.0) |
| | Symptomatic | 237 | | 43 | 0 | 2 | 192 | 95.6% (43/45)
(84.9-99.5) | 100.0% (192/192)
(98.1-100.0) |
| Male Urethra | Asymptomatic | 172 | | 6 | 2 | 1 | 163 | 85.7% (6/7)
(42.1-99.6) | 98.8% (163/165)
(95.7-99.9) |
| | Symptomatic | 412 | | 155 | 6 | 2 | 249 | 98.7% (155/157)
(95.5-99.8) | 97.6% (249/255)
(94.9-99.1) |
| Male Urine | Asymptomatic | 234 | | 6 | 1 | 1 | 226 | 85.7% (6/7)
(42.1-99.6) | 99.6% (226/227)
(97.1-100.0) |
| | Symptomatic | 466 | | 170 | 10 | 1 | 285 | 99.4% (170/171)
(96.8-100.0) | 96.6% (285/295)
(93.5-98.4) |
| Total | Asymptomatic | 1169 | | 59 | 15 | 7 | 1088 | 89.4% (59/66) | 98.6% (1088/1103) |
| | Symptomatic | 1447 | | 415 | 24 | 5 | 1003 | 98.8% (415/420) | 97.7% (1003/1027) |

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Performance Summary Compared to Culture: Fresh Specimens

| Sample Type | Symptomatology | Total | LCx Culture | Pos Pos | Pos Neg | Neg Pos | Neg Neg | Sensitivity (95% C.I.) | Specificity (95% C.I.) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Female Endocervical | Asymptomatic | 78 | | 10 | 3 | 0 | 65 | 100.0% (10/10) (69.2-100.0) | 95.6% (65-68) (87.6-95.1) |
| | Symptomatic | 132 | | 20 | 1 | 0 | 111 | 100.0% (20/20) (83.2-100.0) | 99.1% (111/113) (95.1-100.0) |
| Female Urine | Asymptomatic | 74 | | 9 | 1 | 0 | 64 | 100.0% (9/9) (66.4-100.0) | 98.5% (64/65) (91.7-100.0) |
| | Symptomatic | 129 | | 17 | 1 | 3 | 108 | 85.0% (17/20) (62.1-96.8) | 99.1% (108/109) (95.0-100.0) |
| Male Urethra | Asymptomatic | 74 | | 1 | 0 | 0 | 73 | 100.0% (1/1) (2.5-100.0) | 100.0% (73/73) (95.1-100.0) |
| | Symptomatic | 92 | | 47 | 1 | 0 | 44 | 100.0% (47/47) (92.5-100.0) | 97.8% (44/45) (88.2-99.9) |
| Male Urine | Asymptomatic | 74 | | 1 | 0 | 0 | 73 | 100.0% (1/1) (2.5-100.0) | 100.0% (73/73) (95.1-100.0) |
| | Symptomatic | 93 | | 47 | 1 | 1 | 44 | 97.9% (47/48) (88.9-99.9) | 97.8% (44/45) (88.2-99.9) |
| Total | Asymptomatic | 300 | | 21 | 4 | 0 | 275 | 100.0% (21/21) | 98.6% (275/279) |
| | Symptomatic | 446 | | 131 | 4 | 4 | 307 | 97.0% (131/135) | 98.7% (307/311) |

The analytical sensitivity of this assay (limit of detection) is 10 Colony Forming Units (CFU) of any of the 6 auxotrophs of *Neisseria gonorrhoeae*. The analytical sensitivity of this assay was determined by a serial dilution study on all 6 auxotrophs (auxotype 1, 5, 9, 12, 16, and 23) of *Neisseria gonorrhoeae*. Each auxotroph was diluted to less than 10 CFU per reaction and tested in the LCx *Neisseria gonorrhoeae* Assay. In all cases, each replicate of a dilution giving 10 CFU per test (100 ul specimen volume) was positive by the LCx *Neisseria gonorrhoeae* Assay.

91 bacteria, parasites, viruses, yeast and fungi, including organisms that are commonly found in the urogenital tract and 12 non-gonococcal Neisseria species were tested by the LCx *Neisseria gonorrhoeae* Assay. All gave negative results indicating the specificity of the test.

In conclusion the LCx *Neisseria gonorrhoeae* Assay is substantially equivalent to culture for detection of *Neisseria gonorrhoeae* in endocervical, male urethral, female and male urine specimens.

Prepared and submitted April 1, 1996
Mary Spiewak
847-937-5376
Abbott Laboratories
200 Abbott Park Road
Abbott Park, IL 60064-3537