title: Combined phage typing and amperometric detection of released enzymatic activity for the specific identification and quantification of bacteria.
abstract: Here, we describe a novel electrochemical method for the rapid identification and quantification of pathogenic and polluting bacteria. The design incorporates a bacteriophage, a virus that recognizes, infects, and lyses only one bacterial species among mixed populations, thereby releasing intracellular enzymes that can be monitored by the amperometic measurement of enzymatic activity. As a model system, we used virulent phage typing and cell-marker enzyme activity (beta-D-galactosidase), a combination that is specific for the bacterial strain Escherichia coli (K-12, MG1655). Filtration and preincubation before infecting the bacteria with the phage enabled amperometric detection at a wide range of concentrations, reaching as low as 1 colony-forming unit/100 mL within 6-8 h. In principle, this electrochemical method can be applied to any type of bacterium-phage combination by measuring the enzymatic marker released by the lytic cycle of a specific phage.
authors.affiliation: Department of Molecular Microbiology and Biotechnology, Tel-Aviv University, Ramat-Aviv 69978, Israel.
authors.forename: T
authors.initials: T
authors.lastname: Neufeld
authors.forename: A
authors.initials: A
authors.lastname: Schwartz-Mittelmann
authors.forename: D
authors.initials: D
authors.lastname: Biran
authors.forename: E Z
authors.initials: EZ
authors.lastname: Ron
authors.forename: J
authors.initials: J
authors.lastname: Rishpon
mesh_terms: D001419:Bacteria / Q000166:cytology* / Q000201:enzymology; D001434:Bacteriophage Typing / Q000379:methods*; D004563:Electrochemistry; D004798:Enzymes / Q000032:analysis*
chemical_list: D004798:Enzymes