Rapid Visual Detection of Trace Pseudomonas aeruginosa in Packaged Drinking Water Using Nucleic Acid Test Strips

Abstract

Objective: To establish a new method for the rapid detection of Pseudomonas aeruginosa in packaged drinking water using colloidal gold-based lateral flow immunochromatographic strips. Methods: 1 mg/mL sheep anti-mouse antibody and 1 mg/mL streptavidin (SAV) were sprayed onto a nitrocellulose (NC) membrane by using a membrane sprayer at a rate of 0.5 μL/cm, and then the antibody labeled with fluorescein isothiocyanate (FITC) was conjugated to the surface of colloidal gold by electrostatic adsorption, and the resulting conjugate was added dropwise to the gold standard pad. The amplification products were added dropwise to the fully assembled lateral flow immunochromatographic strip, and the results were judged based on the positions of the control (C) and test (T) lines generated. Results: The method was able to specifically identify P. aeruginosa in packaged drinking water in 3 min with a detection limit of 1 CFU/250 mL, which was more sensitive than agarose gel electrophoresis. Conclusion: The lateral flow immunoassay method was characterized by high sensitivity, high specificity, simplicity and portability, and was suitable for real samples.

Keywords

• pseudomonas aeruginosa; packaging drinking water; lateral flow immunochromatographic strip; rapid detection