Interlaboratory diagnostic accuracy of a Salmonella specific PCR-based method.
A collaborative study involving four European laboratories was conducted to investigate the diagnostic accuracy of a Salmonella specific PCR-based method, which was evaluated within the European FOOD-PCR project (http://www.pcr.dk). Each laboratory analysed by the PCR a set of independent obtained presumably naturally contaminated samples and compared the results with the microbiological culture method. The PCR-based method comprised a preenrichment step in buffered peptone water followed by a thermal cell lysis using a closed tube resin-based method. Artificially contaminated minced beef and whole broiler carcass-rinse resulted in a detection limit of less than 5 cells per 25 g meat or 100 ml broiler rinse. A total of 435 samples from four countries, including pig carcass swabs (n = 285), whole broiler carcass-rinse (n = 25), various raw meat (n = 33), and environmental samples (n = 92) were investigated. The interlaboratory diagnostic accuracy, i.e. diagnostic specificity and sensitivity, was shown to be 97.5%. The co-amplification of an internal amplification control indicated possible inhibitory substances derived from the sample. This work can contribute to the quality assurance of PCR-based diagnostic methods and is currently proposed as international standard document.
Malorny
Burkhard
B
Federal Institute for Risk Assessment, Diedersdorfer Weg 1, D-12277 Berlin, Germany. b.malorny@bfr.bund.de
Hoorfar
Jeffrey
J
Hugas
Marta
M
Heuvelink
Annet
A
Fach
Patrick
P
Ellerbroek
Lüppo
L
Bunge
Cornelia
C
Dorn
Christina
C
Helmuth
Reiner
R
D000818:Animals; D002417:Cattle / Q000382:microbiology; D002645:Chickens / Q000382:microbiology; D008461:Meat Products / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D012475:Salmonella / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013552:Swine / Q000382:microbiology