Bacteriophage Activity on Paper Depends on Paper Properties and Immobilization Method

Bacteriophages are an excellent choice of substrate for detecting bacteria because of their specificity in binding to bacterial cells. Bacteriophages can be immobilized onto a surface which in turn can be used as a dip-stick test to detect concentration of bacterium. However, a problem with using phages for bacterial detection is finding an economical and producer friendly method for immobilizing the virions onto a surface. Some methods which have been utilized include direct addition, adsorption, and chemical binding of phage to a surface. Although, direct addition and adsorption have been successful in immobilizing phage there is still some question about the strength of adhesion of the viruses and whether or not they will remain adhered especially for long storage time or in harsh environmental conditions. On the other hand, chemical binding has proven to be a surer way to maintain immobilized phages on a surface. However, much of the chemical-binding research has been focused on utilizing smooth surfaces. The object of this study was to determine a method of chemically binding bacteriophage onto a porous surface, e.g. filter paper, and to determine the relative advantages and disadvantages of chemically binding bacteriophage versus merely adsorbing or directly adding bacteriophage to filter paper. We were able to utilize the 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/ N-Hydroxysuccinimide (NHS) cross-linker reaction to create amide bonds between the phage and the paper by coating the paper with chitosan and carboxymethyl cellulose (CMC) which provided the necessary carboxyl and primary amine groups needed. The results suggest that the use of polymer treatments and/or using the EDC/NHS cross-linker reaction for immobilization of the bacteriophage can increase the strength of immobilization of bacteriophage on a surface.