Detection of Campylobacter jejuni in naturally contaminated chicken skin by melting peak analysis of amplicons in real-time PCR.
Contamination of poultry by Campylobacter spp. is a significant source of human diarrheal diseases. Traditional methods currently used to detect Campylobacter in foods are time-consuming and labor-intensive. In this study, primers designed for the Campylobacter jejuni cadF gene sequence were used in a SYBR Green I real-time PCR assay as an alternative to a conventional bacteriological method for the rapid detection of C. jejuni from poultry. Twelve portions of chicken purchased from two local grocery stores and 39 portions obtained from a commercial processing plant were examined. Samples of the skin were enriched in Bolton broth at 37 degrees C for 3 h and then at 42 degrees C for 9, 21, or 45 h under microaerobic conditions. DNA was extracted from 1-ml aliquots of the enrichment cultures using 1% Triton X-100. The DNA was used as the template in a real-time polymerase chain reaction (PCR) assay. After 24 h of enrichment, C. jejuni was isolated from 13 samples and all of the positive cultures were also detected by the real-time PCR procedure. C. jejuni was detected by both methods from samples artificially contaminated with 1 or 10 CFU of C. jejuni per 10 g, after 24 h of enrichment. The real-time PCR method was found to be sensitive and specific. It significantly reduced the time required for the detection of C. jejuni in poultry following enrichment of samples.
Oliveira
Tereza C R M
TC
Department of Food and Drug Technology, University of Londrina, Londrina, Parana, Brazil.
Barbut
Shai
S
Griffiths
Mansel W
MW
D000818:Animals; D016123:Campylobacter jejuni / Q000302:isolation & purification*; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D008460:Meat / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D012867:Skin / Q000382:microbiology; D013997:Time Factors