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Detection of meningitis antigens in buffer and body fluids by ultrasound-enhanced particle agglutination
P Jenkins1, R A Barnes, W T Coakley
1School of Pure and Applied Biology, University of Wales Cardiff, UK.
Abstract:
The standard test card agglutination of antibody-coated latex by Neisseria meningitidis. Streptococcus group B, Haemophilus influenzae type b and Streptococcus pneumoniae antigens has been compared with a technique involving local concentration of the coated latex in an ultrasonic standing wave. The detection of positive control antigen was enhanced, compared with the test-card procedure, over a 16 to 64 fold range on exposure to ultrasound. Sample filtration eliminated non-specific agglutination on ultrasonic exposure of latex in control serum, urine or concentrated urine. Tests of meningitis patient body fluids showed increased detection of antigen with ultrasound for CSF (11/14 > 7/14) serum (8/13 > 3/13) and concentrated urine (8/17 > 2/17) compared to test card assays. The ultrasound detection of antigen in serum or concentrated urine was comparable to that achieved with CSF on test cards. Serum dilution experiments showed that ultrasound could detect antigen in serum over a 1000 fold concentration range.
Insights
Ultrasonic standing waves enhance latex agglutination tests for detecting bacterial meningitis antigens. This improved method increases sensitivity for crucial pathogens like Neisseria meningitidis in patient samples.
Area of Science:
- Microbiology
- Immunology
- Biotechnology
Background:
- Standard latex agglutination tests are used for detecting bacterial antigens.
- Sensitivity limitations exist in current diagnostic methods for meningitis pathogens.
Purpose of the Study:
- To evaluate an enhanced latex agglutination technique using ultrasonic standing waves.
- To compare the sensitivity of ultrasound-enhanced agglutination with standard test cards for meningitis-causing bacteria.
Main Methods:
- Antibody-coated latex particles were concentrated using ultrasonic standing waves.
- Detection of antigens from Neisseria meningitidis, Streptococcus group B, Haemophilus influenzae type b, and Streptococcus pneumoniae was assessed.
- Patient cerebrospinal fluid (CSF), serum, and concentrated urine samples were tested.
Main Results:
- Ultrasonic concentration enhanced antigen detection 16- to 64-fold compared to standard test cards.
- Sample filtration effectively eliminated non-specific agglutination.
- Ultrasound improved antigen detection in CSF (11/14 vs 7/14), serum (8/13 vs 3/13), and concentrated urine (8/17 vs 2/17).
Conclusions:
- Ultrasonic standing wave concentration significantly improves the sensitivity of latex agglutination assays for bacterial meningitis antigens.
- This technique offers a promising enhancement for rapid and sensitive pathogen detection in clinical samples, comparable to CSF test card results even in serum and urine.