An Improved Pre-culture Procedure for the Detection of Salmonella in Frozen Chicken Meat by Duplex Polymerase Chain Reaction
WEI-TANG CHEN1, SHU-JEAN TSAI2, DANIEL YANG-CHIH SHIH2, YUEH-JONG CHUNG WANG2 AND CHU-YING LOU CHYR1*
1. Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan (R.O.C.)
2. Bureau of Food and Drug Analysis, Department of Health, Executive Yuan, Taipei, Taiwan (R.O.C.)
(Received: January 25, 2008; Accepted: May 24, 2008)
ABSTRACT
An improved 18-hour pre-culture procedure coupling with duplex polymerase chain reaction (PCR) method capable of detecting Salmonella in frozen chicken meat is herein reported. Two pairs of primers (TS5/TS11 and S18/S19) were used for the PCR method. Positive PCR results were obtained after the 18-hour preculture (6 h in lactose broth at 37°C followed by 12 h in Rappaport-Vassiliadis broth at 42°C) for spiked raw and irradiated meats with or without freezing treatment. The applicability of this improved procedure was tested in 50 retail frozen and 50 non-frozen chicken drumstick samples, and the results were compared with those obtained with the BAM standard culture method. No significant difference was found (p ^ 0.05) between these two methods.
Key words: pre-culture, duplex PCR, Salmonella, frozen chicken meat