The School of Chemistry congratulates Prof. Doron Shabat on winning the Kadar Family Award for Outstanding Research in the Senior Category

Congratulations to Prof. Doron Shabat for winning the Kadar Family Award. The award has been given for an Outstanding Research in the Senior Category.

A team led by Prof. Shabat at the University of Tel Aviv, Nemis Technologies AG (Zurich, Switzerland), and Biosynth AG (Staad, Switzerland) have introduced a new and efficient method for the ultrasensitive and significantly faster detection of salmonella and listeria. The method is based on chemiluminescence – the emission of light resulting from a chemical process. The simplicity of the tests allows for both enrichment of the bacteria and their detection in a test tube, with no further sample preparation, so no containment laboratory is required. The chemiluminescence probes have proven to be about 600 times more sensitive than conventional fluorescence probes. The success of this technique is due to two specially developed probe molecules made by combining a luminescent substance with a “trigger”. In this form, the probe does not light up. The trigger is tailored to the bacteria to be detected: it is recognized by a specific enzyme produced by the pathogen – a special esterase in the case of salmonella and a special phospholipase C for listeria – that splits it from the luminescent part. This initiates a chemical reaction that causes the luminescent molecule to split off more pieces. The energy released by the reaction is emitted in the form of a very intense green glow. Tests with various bacteria demonstrated that the probe tailored for salmonella only reacts to salmonella, and the listeria test only reacts to Listeria monocytogenes, not to other, non-pathogenic, strains of listeria. The intensity of the glow can be used to quantify the concentration of bacteria. The tests are so sensitive that, for example, a count of ten salmonella can be detected within six hours of enrichment. Even dried bacteria can be swabbed from surfaces and detected. The new method developed by Prof. Shabat and his research team can be used more broadly to develop specific chemiluminescence probes for detection of other bacteria.