Factors affecting the recovery of Campylobacter spp. from  retail packs of raw, fresh chicken using ISO 10272-1:2006.
OBJECTIVE
This study sought to determine the most effective protocol for the detection of Campylobacter spp. in retail packs of fresh, raw chicken based on ISO 10272-1:2006.


RESULTS
Three sample preparation protocols were studied; two based on excision and one combining excision with a rinse of the remaining sample. Enrichment cultures were incubated both in closed bottles and microaerobically, and sub-cultured at 24 and 48 h. Packs of chicken (110) were analysed and only two yielded no Campylobacter spp. Subculturing enrichment broths at 24 h gave the same prevalence as at 48 h, P > 0.4 but microaerobic incubation yielded approximately 50% more positive samples than did incubation in closed bottles. Sampling based on excision plus rinsing gave the highest Campylobacter prevalence (92.7%).


CONCLUSIONS
To isolate Campylobacter spp. from retail packs of chicken, enrichment cultures must be incubated in a microaerobic atmosphere and sub-cultured at 24 h and, possibly, 48 h. Sampling packs by excision plus rinsing maximized recoveries.


CONCLUSIONS
ISO 10272-1:2006 permits the use of inefficient protocols which markedly underestimate the true prevalence of Campylobacter spp. in retail, fresh chicken. Equivalent results could be obtained 24 h earlier, with consequent savings. Its revision is essential.
Food Microbiology Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast, UK.
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Moran
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Kelly
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Madden
D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods*; D002167:Campylobacter / Q000235:genetics / Q000302:isolation & purification*; D002645:Chickens; D005506:Food Contamination / Q000032:analysis* / Q000706:statistics & numerical data; D007390:International Agencies / Q000592:standards; D008460:Meat / Q000382:microbiology*