Factors affecting the recovery of Campylobacter spp. from retail packs of raw, fresh chicken using ISO 10272-1:2006

Authors


Robert H. Madden, Food Microbiology Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK. E-mail: bob.madden@afbini.gov.uk

Abstract

Aims:  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.

Methods and 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, > 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.

Significance and Impact of the Study:  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.

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