Evaluation of different DNA extraction procedures for the detection of Salmonella from chicken products by polymerase chain reaction.
Polymerase chain reaction (PCR) was used after a short pre-enrichment culture to detect Salmonella subspecies in chicken fillets. A direct PCR assay performed with chicken meat inoculated with Salmonella Typhimurium produced no PCR products. Six different DNA extraction protocols were tested to recover efficiently Salmonella DNA after a short incubation period. Three of them gave results that were reliable, rapid and sensitive. Successful protocols used Proteinase K and/or a centrifugation step to concentrate the samples. For reliable detection of Salmonella subspecies, a few thousand bacterial cells per ml must be present. To obtain this number of bacterial cells with an inoculation of about one cell in 25 g of ionized food products, it was necessary to incubate samples for at least 10 h before PCR. A larger inoculum of approximately 10 cells in 25 g of ionized food products, required 8 h in culture broth to give positive results by PCR-based assay.
Soumet
C
C
Laboratoire Central de Recherches Avicole et Porcine, Ploufragan, France.
Ermel
G
G
Fach
P
P
Colin
P
P
D000818:Animals; D002645:Chickens; D004269:DNA, Bacterial / Q000302:isolation & purification*; D008460:Meat / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012475:Salmonella / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
D004269:DNA, Bacterial