Rapid detection of Pseudomonas aeruginosa by cross priming amplification

Abstract

Pseudomonas aeruginosa (PA) is an opportunistic pathogen of humans and animals and a common source of nosocomial infections especially of the respiratory tract. Pseudomonas aeruginosa is also a major bacterial disease of poultry and in particular, eggs and newly hatched chicks. In this study, we developed a simple, accurate and rapid molecular detection method using cross priming amplification (CPA) with a nucleic acid test strip to detect P. aeruginosa. The assay efficiently amplified the target gene within 45 min at 62°C only using a simple water bath. The detection limit of the method was 1.18×10² copies μL⁻¹ for plasmid DNA and 4.4 CFU mL⁻¹ for bacteria in pure culture, and was 100 times more sensitive than conventional PCR. We screened 83 clinical samples from yellow-feather broiler breeder chickens and hospitalized/treated dogs and cats using CPA, PCR and traditional culture methods. The positive-sample ratios were 15.3% (13/83) by CPA, 13.3% (11/83) by PCR and 12.1% (10/83) by the culture method. The established CPA method has significant advantages for detecting P. aeruginosa. The method is easy to use and possesses high specificity and sensitivity without the requirements of complicated experimental equipment. The PA-CPA assay is especially fit for outdoor and primary medical units and is an ideal system for the rapid detection and monitoring of P. aeruginosa.