RAPID PCR WITH NESTED PRIMERS FOR DIRECT-DETECTION OF CAMPYLOBACTER-JEJUNI IN CHICKEN WASHES

Rapid detection of Campylobacter jejuni by PCR directly from foods, wi thout prior growth steps, would be beneficial for the poultry industry . We have previously reported a PCR assay that allows detection of thi s bacterium after 48 h growth on Campy cefex agar. We have now develop ed a more rapid nested PCR assay that specifically detects C. jejuni i n chicken washes that have not undergone any lengthy growth steps prio r to PCR. For the nested reaction, an external set of primers, C-l and C-4, are used for 24 cycles. At this time, 1 mu l of the PCR product is removed and added to a second reaction. The second PCR assay is run with C-l and an internal primer, C-2, for 24 cycles. A single band on a 4% NuSieve agarose gel at 122 bp was apparent with C. jejuni cells at a sensitivity of 10(2) cfu ml(-1). With this method chicken carcass es can be washed and C. jejuni identified all within 1 day. We detecte d C. jejuni in approximately 80% of four groups of chickens using this method. The identifications have been confirmed by standard microbiol ogical techniques. (C) 1997 Academic Press Limited.