Detection of Campylobacter jejuni added to foods by using a combined selective enrichment and nucleic acid sequence-based amplification (NASBA).
An assay to detect Campylobacter jejuni in foods that uses a short selective enrichment culture, a simple and rapid isolation procedure, NASBA amplification of RNA, and a nonradioactive in solution hybridization was studied. The presence of high numbers of indigenous flora affected the sensitivity of the assay. However, detection of C. jejuni was possible up to a ratio of indigenous flora to C. jejuni of 10,000:1. Interference by food components was eliminated by centrifugation following the enrichment step. Fourteen food samples artificially inoculated with C. jejuni (1 to 1,000 CFU/10 g) were analyzed with the NASBA assay and the conventional culture method with Campylobacter charcoal differential agar (CCDA). A few false-negative results were obtained by both NASBA (1.42%) and CCDA (2.86%) isolation. Yet the use of enrichment culture and NASBA shortened the analysis time from 6 days to 26 h. The relative simplicity and rapidity of the NASBA assay make it an attractive alternative for detection of C. jejuni in food samples.
Uyttendaele
M
M
Department of Food Technology and Nutrition, Faculty of Agricultural and Applied Biological Sciences, University of Ghent, Belgium.
Schukkink
R
R
van Gemen
B
B
Debevere
J
J
D000818:Animals; D001431:Bacteriological Techniques / Q000706:statistics & numerical data; D016123:Campylobacter jejuni / Q000235:genetics / Q000302:isolation & purification*; D003470:Culture Media; D015342:DNA Probes; D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D005516:Food Microbiology; D005784:Gene Amplification; D009693:Nucleic Acid Hybridization; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012680:Sensitivity and Specificity
D003470:Culture Media; D015342:DNA Probes; D012336:RNA, Ribosomal, 16S