The development of a combined surface adhesion and polymerase chain reaction technique in the rapid detection of Listeria monocytogenes in meat and poultry.
A procedure combining enrichment surface adhesion and polymerase chain detection (SA-PCR) was developed and applied in the detection of Listeria monocytogenes in meat products. Minced beef samples were inoculated with L. monocytogenes (log(10)3 cfu g(-1)) and incubated for 10 h at 30 degrees C in buffered peptone water. L. monocytogenes was recovered from the culture by attachment to a polycarbonate membrane immersed for 15 min in the enriched meat culture. The membrane and attached bacteria were removed from the culture and the membrane dissolved in phenol:chloroform. The DNA was extracted from the bacteria and a PCR assay was carried out using primers directed against the listerolysin O gene of L. monocytogenes. The combined (SA-PCR) technique had a detection limit of log10 4.0 cfu ml(-1) in enriched meat cultures. The rapid technique was applied to a small number of retail samples (n = 100) and was found to compare favourably to the standard cultural method. A total of 12 samples were confirmed positive for L. monocytogenes using the standard cultural method and the SA-PCR assay. No false positives or negatives were recorded by either method.
Duffy
G
G
The National Food Centre, Teagasc, Dunsinea, Castleknock, Dublin, Ireland.
Cloak
O M
OM
Sheridan
J J
JJ
Blair
I S
IS
McDowell
D A
DA
D000818:Animals; D002417:Cattle; D002645:Chickens; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D008461:Meat Products / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D013499:Surface Properties