Simple steps to stem killer bacteria - News & Features

24 March 2017
Simple steps to stem killer bacteria

The School of Veterinary Science at the University of Bristol has published the results from its 3-year survey of factors influencing campylobacters in chicken broiler houses.

Campylobacter is the most common cause of food poisoning in the UK and the bacteria is responsible for more than 280,000 cases of food poisoning each year.

Costly killer

It’s invisible to the naked eye, odourless and cannot be tasted on food, yet Campylobacter can kill and costs the UK economy approximately £900 million. About four in five cases of Campylobacter poisoning in the UK come from contaminated poultry.

Results from samples taken between 2013 and 2016 have now been published in the Journal of Applied Microbiology, which also includes the findings presented by an earlier EU-wide survey identifying that some slaughterhouses were better at removing Campylobacter species from broiler carcasses compared with others.

Chicken choices

The research published in Journal of Applied Microbiology outlines how reductions in campylobacter levels could be made through cost effective changes in farming best practice. For the independent farms, bird gender, age at slaughter, shed size and the shed frame construction material were significant predictors of numbers of Campylobacter in litter. 

Farm findings

•   Houses containing exclusively female birds had lower Campylobacter levels compared with sheds containing male gender birds.  Mixed gender sheds also tended to have significantly lower counts.

•   If prebiotics were fed to birds, the mean log10 count was increased by 1.400 (p < 0.001).

•   It is also established that freezing chickens (Haughton et al. 2012) and chicken meat (Harrison et al. 2013) can lower numbers of Campylobacter.

•   The presence of darkling beetles in the litter was significantly correlated with elevated Campylobacter numbers

•  Farmers that excluded their dogs from the houses had significantly decreased numbers of Campylobacter species in the litter

•   Increasing the frequency of dipping boots in disinfectant was significantly correlated with lowered numbers of Campylobacter species in house litter

Mike Hutchison, who managed the study at the University of Bristol School of Veterinary Sciences said:  

“An initial model to predict numbers of campylobacters on broiler carcass neck skins after chilling determined that more than three times the variance observed in slaughterhouses was explained by on-farm factors. Therefore, it is likely that farm-based interventions would be more financially and practically effective in lowering flock colonisations by campylobacters”

Key interventions

Clare Taylor, Senior Lecturer in Medical Microbiology at Edinburgh Napier University and General Secretary of the Society for Applied Microbiology (SfAM) said:

“In recent years we have seen reports that campylobacters are present in around 75% of supermarket chickens. And with an increasing focus on the reduction of the use of antibiotics in animal husbandry, it is clear that hygienic practices in poultry processing can play a key role in reducing contamination. The authors of this study have identified a number of key interventions that could reduce Campylobacter contamination and improve food safety.”