Selective mycobacterial capture with ultraviolet-polymerized poly-dimethyldiallyl chloride functionalized surfaces.

Area of Science:

• Microbiology
• Materials Science
• Medical Diagnostics

Background:

• Tuberculosis (TB) remains a leading infectious cause of death globally.
• Current direct smear microscopy for TB diagnosis has limited sensitivity (~50%).
• Molecular diagnostics like Cepheid GeneXpert MTB/RIF are effective but not universally accessible.

Purpose of the Study:

• To develop and characterize a novel polymer-coated material for enhanced mycobacterial capture.
• To improve the analytical performance of smear microscopy for TB detection.
• To assess the efficacy of this new diagnostic platform in a clinical setting.

Main Methods:

• UV photopolymerization of Polydiallyldimethylammonium chloride (PDADMAC) on functionalized polystyrene (PS).
• Plasma activation of PS for monomer engraftment.
• Testing the platform on sputum samples from presumptive TB cases in Uganda (n=50).

Main Results:

• The novel polymer-coated platform demonstrated increased sensitivity of 81.8% compared to fluorescent smear microscopy (57%).
• Performance was validated against the Cepheid GeneXpert MTB/RIF molecular standard.
• The diagnostic innovation is rapid and requires no specialized instrumentation.

Conclusions:

• The PDADMAC-engrafted polystyrene platform significantly enhances TB smear microscopy sensitivity.
• This frugal diagnostic innovation presents a promising solution to address the global TB diagnostic gap.
• The technology offers a rapid, low-cost method for improved TB detection in resource-limited settings.