DIRECTIGEN MENINGITIS COMBO TEST

K952791 · Bd Becton Dickinson Vacutainer Systems Preanalytic · GTJ · May 30, 1996 · Microbiology

Device Facts

• Record ID: K952791
• Device Name: DIRECTIGEN MENINGITIS COMBO TEST
• Applicant: Bd Becton Dickinson Vacutainer Systems Preanalytic
• Product Code: GTJ · Microbiology
• Decision Date: May 30, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3390
• Device Class: Class 2

Indications for Use

The Directigen® Meningitis Test Kits are a presumptive latex agglutination test for the direct qualitative detection of antigens to H. influenzae type b, S. pneumoniae, group B Streptococcus, N. meningitidis groups A, B, C, Y or W135 and E. coli K1 in cerebrospinal fluid (CSF), serum, urine, or blood culture media. Visible agglutination occurs when a sample containing any of these bacterial antigens is reacted with its respective antibody-coated latex beads. This 510(k) was submitted to add colony confirmation and serotyping claims to the Intended Use Statement.

Device Story

Directigen® Meningitis Test is a latex agglutination assay for bacterial antigen detection. Input: clinical samples (CSF, serum, urine, blood culture) or bacterial colonies. Principle: specific antibodies bound to latex beads; presence of target bacterial antigens causes visible particle aggregation (agglutination). Output: qualitative visual result (positive/negative). Used in clinical microbiology laboratories by trained technicians. Results provide rapid presumptive identification of pathogens, aiding clinical decision-making for meningitis and systemic infection management. Benefits: faster pathogen identification compared to traditional culture methods, facilitating timely targeted antibiotic therapy.

Clinical Evidence

Two external studies evaluated colony confirmation and serogrouping performance. Total sample sizes ranged from 94 to 129 per organism group. Relative sensitivity ranged from 85% (N. meningitidis Group B) to 100% (H. influenzae type b, Group B Strep, N. meningitidis Group A/Y). Relative specificity ranged from 79% (S. pneumoniae) to 100% (N. meningitidis Group A/Y and B). Uninterpretable results occurred in 0% to 11.7% of initial tests. Limitations noted regarding potential cross-reactivity with S. viridans and non-specific agglutination with certain morphologically similar isolates.

Technological Characteristics

Latex agglutination assay. Components: latex beads coated with specific antibodies. Principle: visual agglutination upon antigen-antibody binding. Manual test format. No electronic or software components.

Indications for Use

Indicated for presumptive qualitative detection of H. influenzae type b, S. pneumoniae, group B Streptococcus, N. meningitidis (groups A, B, C, Y, W135), and E. coli K1 antigens in CSF, serum, urine, blood culture media, or from suspected bacterial colonies for confirmation and serotyping.

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.

Predicate Devices

• Phadebact® S.pneumoniae and H.influenzae co-agglutination tests
• Phadebact® Streptococcus Test (A,B,C,G)
• Strep A Test
• Strep B Test
• Strep D Test
• Strep F Test
• Bacto Antisera for N.meningitidis groups A,B,C,D,X,Y,Z,Z', and W135

Submission Summary (Full Text)

{0}

MAY 29 '96 01:08PM BDMS/33
K952791
MAY 30 1996 May 29, 1996

# SUMMARY OF SAFETY AND EFFECTIVENESS

SUBMITTED BY:

Judith J. Smith
Becton Dickinson Microbiology Systems
P O Box 243
Cockeysville, MD 21030-0243

NAME OF DEVICE:

Trade Name: *Directigen® Meningitis Combo Test*
*Directigen® Neisseria meningitidis* Test

Common Name/Description: Latex agglutination antigen detection kit

Classification Name: Antisera, All groups; N.meningitidis

PREDICATE DEVICE: Phadebact® *S.pneumoniae* and *H.influenzae* co-agglutination tests; Phadebact® Streptococcus Test (A,B,C,G) and Strep A Test, Strep B Test, Strep D Test, and Strep F Test; Bacto Antisera for *N.meningitidis* groups A,B,C,D,X,Y,Z,Z', and W135.

DEVICE DESCRIPTION:

**INTENDED USE:** The *Directigen® Meningitis Test* Kits are a presumptive latex agglutination test for the direct qualitative detection of antigens to *H. influenzae* type b, *S. pneumoniae*, group B *Streptococcus*, *N. meningitidis* groups A, B, C, Y or W135 and *E. coli* K1 in cerebrospinal fluid (CSF), serum, urine, or blood culture media. Visible agglutination occurs when a sample containing any of these bacterial antigens is reacted with its respective antibody-coated latex beads. This 510(k) was submitted to add colony confirmation and serotyping claims to the Intended Use Statement.

**KIT DESCRIPTION:** Specific antibodies are bound to the surface of latex beads. In the presence of specific antigens, latex particle aggregation becomes large enough to allow visualization of positive agglutination. These specific soluble polysaccharide antigens accumulate in CSF, serum, urine or blood as a result of infection by *H. influenzae* type b, *S. pneumoniae*, group B *Streptococcus*, *N. meningitidis* groups A, B, C, Y or W135 and *E. coli* K1.

B-1

{1}

P.3/3

# PERFORMANCE DATA:

**Clinical Correlation:** Two external studies were conducted to enable the addition of a claim for the *Directigen®* Meningitis Test Kits by providing colony confirmation and serogrouping capabilities from suspected colony growth for *S. pneumoniae*, *H. influenzae* type b, group B *Streptococcus*, *N. meningitidis* groups A, B, C, Y, or W135.

**Conclusion:** The *Directigen®* Meningitis Test Kits demonstrated acceptable performance for all latex reagents for serologic identification of each respective pathogen from culture plates.

| Suspected Organism | # Tested | Relative Sensitivity (95% Confidence Interval) | Relative Specificity (95% Confidence Interval) | % Uninterpretable Initial Testing |
| --- | --- | --- | --- | --- |
| *H. influenzae* type b | 112 | 100% (92-100) | 98.5% (92-100)^{2} | 3.6% |
| *S. pneumoniae* | 124 | 93% (84-98) | 79% (66-88)^{1} | 0% |
| Group B Streptococcus | 129 | 100% (95-100) | 90.5% (80-96)^{1} | 0% |
| *Neisseria meningitidis* Group A/Y | 106 | 100% (83-100) | 100% (96-100)^{2} | 10.4% |
| *Neisseria meningitidis* Group C/W135 | 94 | 96% (82-100) | 98.5% (92-100)^{2} | 11.7% |
| *Neisseria meningitidis* Group B | 106 | 85% (55-98) | 100% (96-100)^{2} | 4.7% |

1- Refer to Limitations of the Procedure
2 - Results after repeat testing with 1:10 dilution

Based on the clinical trial data, a footnote has been added to the data summary table referring the user to the Limitations of the Procedure regarding the possibility of cross-reactivity with some strains of *S. viridans* group with the *S. pneumoniae* latex reagent. Additional tests may be needed to differentiate *S. viridans* from *S. pneumoniae*. In addition, certain bacterial isolates obtained from blood culture plates which are morphologically similar to, but gram stain inconsistent with the suspect colony, may exhibit non-specific agglutination and/or false positive reactions (ie. beta-hemolytic nonpathogenic Neisseria species with the Group B Strep latex). Therefore, a gram stain result should be performed prior to use with the colony confirmation procedure.

B-2