Submitted to: Journal of Microbiological Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 11, 2007
Publication Date: January 1, 2007
Citation: Mclaughlin, M.R. 2007. Simple colorimetric microplate test of phage lysis in Salmonella enterica. Journal of Microbiological Methods. 69:394-398.
Interpretive Summary: Special media and micro methods were used to detect surviving Salmonella cells following treatment with a Salmonella-killing bacteriophage (phage). A colorless additive in the media affects only living cells, staining them red for faster detection. Michael McLaughlin, an ARS research scientist in the Waste Management and Forage Research Unit at Mississippi State, MS developed the microplate method incorporating the media additive. The method was used to describe the interactions of phage and bacteria in very small volumes of test media. The effects of phage concentrations on Salmonella growth and survival were determined. This method should be useful in defining phage-host interactions, testing phage biocontrol treatments, and prescribing phage mixtures for pathogen prevention and control applications.
A colorimetric microplate method for characterizing phage-host interactions was developed, described, and applied in a Salmonella phage system. Combinations of phage and host concentrations were examined and tetrazolium was used to assess cell survival. The test was simple, used only liquid media and produced qualitative and quantitative results. Monitoring in a microplate reader enhanced quantitative potential and allowed more precise interpretation of results. The method should be useful in defining phage-host interactions, testing phage biocontrol treatments, and specifying phage cocktails for pathogen prevention, suppression, and elimination.