Development of an artificial zinc finger – Luciferase fusion protein for the rapid detection of Salmonella typhimurium

A novel artificial Zinc finger – luciferase fusion protein was successfully developed for rapid detection of Salmonella typhimurium, a worldwide-distributed foodborne pathogen. The designed Zinc finger (ZF) protein bound specifically to a 12 bp region of the Salmonella spp invasion gene invA. While the luciferase from Gaussia princeps called Gaussia luciferase (Gluc) was for the first time fused with the artificial ZF domain to improve the detection sensitivity. The fusion protein successfully recognized and bound to the synthesized invA dsDNA with high specificity and sensitivity. The detection limit was as low as 10 fmol of dsNDA. Then, the bacteria PCR products were subsequently used to assess the zinc finger – luciferase fusion protein. The final results indicated that the ZF-Gluc fusion protein system could detect S. typhimurium as low as 1 CFU/mL in 2 h after the PCR. Therefore, this study provided us with a novel artificial zinc finger fusion protein and an efficient method to accomplish the rapid detection of the major foodborne pathogen S. typhimurium. In addition, the specific artificial ZF proteins that bund to particular dsDNA sequences could be easily designed, the ZF-Gluc might has broad application prospects in the field of rapid pathogenic bacteria detection.