Melons and glowing eggs

By Siouxsie Wiles 20/08/2012

Yesterday’s post on the current melon Salmonella outbreak reminded me of an old paper I read once. Alas, its not open access so it will cost you US$37 (+ tax it says…) if you want to read it, but you can get the gist from the abstract.

To summarise, bacteria can fall victim to viruses just like us. These viruses are often called phage or bacteriophage. The interaction between phage and host is very specific with a particular phage only infecting a single or very closely related species of bacteria. Jinru Chen and Mansel Griffiths added the genes for bioluminescence to a phage that specifically infects Salmonella.

Because viruses highjack the machinery of the invaded cell to make their proteins, the phage don’t produce light until they have infected a Salmonella bacterium. The authors showed that this elegant system could be used to detect Salmonella from within contaminated eggs – just inject in a preparation of the phage and if the bacteria are present the eggs glow!

Reference: Chen, J & Griffiths, MW. (1996). Salmonella Detection in Eggs Using Lux+ Bacteriophages. Journal of Food Protection, 59 (9): 908-914.