A UK survey of campylobacter and salmonella contamination of fresh chicken at retail sale

A UK-wide survey was undertaken by the Agency between May 2007 and September 2008 to determine campylobacter and salmonella prevalence on fresh chicken at retail. A total of 3,274 samples were tested using presence/absence methods for the detection of campylobacter and salmonella. Between April 2008 and August 2008 a subset of 927 samples were also tested using a campylobacter enumeration method.

It is well recognised that campylobacter can be a difficult organism to isolate in the laboratory and that the presence/absence method has limitations. Recent literature suggests that using a combination of presence/absence and enumeration testing provides a more robust measure of campylobacter prevalence. The overall prevalence figure for this survey was determined by combining the campylobacter positive results from the 927 samples tested by both presence/absence and enumeration methods.

The prevalence of campylobacter in chicken at retail in the UK was 65.2% based on the combined methods for the 927 samples tested.

Overall, Campylobacter jejuni accounted for 52.9% of the campylobacter isolates found in the survey, compared with 47.1% for C. coli.

A total of 197 (13%) campylobacter isolates were sensitive to all the antimicrobial drugs that were screened for, representing an increase in the frequency of antimicrobial resistance compared to the 2001 survey. Resistance to quinolones also increased.

Salmonella prevalence in chicken at retail remained low at 6.6%.

Thirty different salmonella serotypes were isolated during the survey. Salmonella Kentucky and Salmonella Bredeney were found most frequently, accounting for 11.5% and 9.7% of the isolates respectively.

There has been a decrease in antimicrobial resistance of salmonella isolates compared with the 2001 survey. However, there has been an increase in cephalosporin and fluoroquinolone resistance and in the range of salmonella serotypes showing multi-drug resistance.

A significant proportion of fresh chicken on sale in the UK remains contaminated with campylobacter. Therefore, working with industry to reduce these levels, and consequently the associated risk of foodborne disease, continues to be a high priority for the Agency.

The survey has also shown that there have been shifts in the Campylobacter spp. and Salmonella serotypes isolated since the 2001 survey. Antimicrobial resistance levels have also changed. However, human salmonella and campylobacter infections are rarely treated with antibiotics and the primary concern is the presence of these organisms in food.

The full technical report is available on foodbase at the link below.