Details

Autor(en) / Beteiligte

• HOUGH, Angela J
• HARBISON, Sally-Ann
• SAVILL, Marion G
• MELTON, Laurence D
• FLETCHER, Graham

Titel

Rapid enumeration of Listeria monocytogenes in artificially contaminated cabbage using real-time polymerase chain reaction

Ist Teil von

• Journal of food protection, 2002-08, Vol.65 (8), p.1329-1332

Ort / Verlag

Des Moines, IA: International Association of Milk, Food and Environmental Sanitarians

Erscheinungsjahr

2002

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• A quantitative real-time polymerase chain reaction (PCR) detection method specific for Listeria monocytogenes was developed, and studies involving pure culture showed that the response of the assay was linear over 7 log10 (log) cycles. The method was then applied to the detection of L. monocytogenes artificially inoculated onto cabbage, a vegetable chosen because it is a major component of coleslaw, which has been associated with an outbreak of listeriosis. After being allowed to attach to the food, cells were washed from the cabbage leaf surface and recovered by centrifugation. The DNA was purified by an organic solvent extraction technique and analyzed by real-time PCR. In this matrix, the method again produced a linear response over 7 log cycles from 1.4 x 10(2) to 1.4 x 10(9) CFU of L. monocytogenes in 25 g of cabbage, and analysis of the reproducibility of the system showed that log differences in L. monocytogenes numbers added to cabbage could be reliably distinguished. The system allowed quantitative results to be obtained within 8 h and was relatively inexpensive, showing good potential for routine analytical use.