SMELLING PSEUDOMONAS AERUGINOSA INFECTIONS USING A WHOLE-CELL BIOSENSOR

Igor Kviatkovski ¹ Sagit Shushan ^2,4 Idan Frumin ² Daniel Amir ² Lavi Secundo ² Eitan Livne ² Aharon Weissbrod ² Tali Yarnitzky ³ Noam Sobel ² Yael Helman ¹

¹Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot
²Department of Neurobiology, Weizmann Institute of Science, Rehovot
³Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot
⁴Ear, Nose and Throat Department, Edith Wolfson Hospital, Holon

Improved easy-to-use diagnostic tools for infectious diseases are in strong demand worldwide. Despite dramatic advances in diagnostic technologies, the gold-standard remains culturing. This method is prone to contamination and requires specialized laboratories for analyses. The presented study describes the use of a luminescent bacterial biosensor for detection of Pseudomonas aeruginosa infections. Detection was based on specific binding between a LuxR receptor and 2-aminoacetophenone (2-AA), a volatile molecule produced in high amounts by P. aeruginosa.

Pus samples collected from infected ears of subjects exhibiting symptoms of otitis externa were analyzed with a luxR based biosensor. Results demonstrated >90% accuracy in comparison to the gold-standard culturing assay, and >95% accuracy in comparison to gas-chromatograph mass-spectrometry (GC-MS) analyses of 2-AA in pus sample head-space. Further, a modified LuxR receptor was generated by replacing three amino acids in the binding pocket of the receptor. The modified receptor exhibited higher specificity and sensitivity towards 2-AA, thereby improving the ability to detect low amounts of 2-AA. Despite recent developments in bacterial whole-cell biosensors, they have not been extensively applied in the medical arena. Here we first demonstrated that the volatile molecule 2-AA serves as an effective biomarker for P. aeruginosa in ear infections, and that 2-AA activation of the biosensor provides a unique opportunity to design an easy-to-use device that can “smell” P. aeruginosa infections.