Abstract: A polymerase chain reaction (PCR) assay for the detection of Pseudomonas fluorescens in foods was developed in this study. Six pairs of detection primers were designed for the 16－23S rDNA internal transcribed spacer sequence, the gyrB gene and 4 specific genes obtained by bioinformatics, respectively. Primary specificity experiments were used to screen the best primer pair out of them. A PCR amplification system targeting the gyrB gene was constructed and evaluated. The results indicated that the developed assay could specifically detect Pseudomonas fluorescens. The specificity was 14.9 fg/μL for pure DNA, 2.8 × 102 CFU/mL for pure culture and 0.28 CFU/ 25 g for soybean milk with 15 h enrichment.

Key words: Pseudomonas fluorescens, gyrB gene, polymerase chain reaction (PCR) , detection, food