(718e) Rapid Bacteria Isolation and Recovery Using Biodegradable Layer-By-Layer Film Coated Hollow Glass Microspheres

Isolation, recovery and detection of Salmonella from food samples and bodily fluids is essential for elimination or significant reduction of such infections. Currently used traditional isolation techniques such as culture-based isolation are time consuming and take 4-5 days for Salmonella confirmation. Newly developed rapid isolation techniques such as microfluidics and immunomagnetic nanoparticles mediated isolation need sophisticated lab equipment, tedious microfabrication or may impact cell viability, function and phenotype due to nanoparticle interaction and magnetic forces. These limitations of the established Salmonella isolation techniques make them inaccessible in resource limited areas. Here, we present a rapid yet simple method for specific Salmonella isolation and recovery from mixed bacterial populations using self-floating hollow glass microspheres (HGMS), coated with biodegradable layer-by-layer (LbL) biomaterial films and Salmonella specific antibodies. This method bypasses the limitations posed by established isolation techniques mentioned earlier as it does not require any sophisticated laboratory equipment, trained personnel or external force (electric, magnetic or optical). Salmonella were captured due to antigen antibody interactions on the surface of HGMS and allowed to float to the top. Then HGMS were washed and subjected to enzymatic degradation of the LbL films for recovery of captured bacteria. The whole process took less than two hours. Recovered Salmonella were then allowed to further grow by inoculation on agar plates for further analysis. To validate our method, we do an extensive characterization of LbL film formation and enzymatic degradation, capture and recovery at various concentrations and in different food and bodily fluid matrices, simulation of motion of the HGMS during capture process and fluorescent confirmation of Salmonella. This method is expected to provide an alternative to traditional isolation techniques in resource limited areas.