Hygiene control during broiler processing:technological and managerial aspects

Poultry can be a source of biological hazards for consumers. Campylobacteriosis, for example, has been the most frequently reported zoonosis in European Union since 2005. Annually the number of campylobacteriosis cases in humans in the EU is estimated at 9 million cases. To diminish this number, risk assessment studies suggest that reducing the number of Campylobacter on chicken meat is needed. Potentially, such interventions could be effective for other hazards as ESBL/AmpC producing E. coli, and the level of process control could be measured by generic E. coli. However concentrations of Campylobacter, ESBL/AmpC producing E. coli and generic E. coli along the processing were not yet known. The aim of this thesis was to study changes in the contamination of broiler chicken carcasses with Campylobacter, ESBL/AmpC producing E. coli and generic E. coli through the broiler processing line, and to identify and quantify factors related to processing technology and management that might influence these changes. The results obtained in this thesis can be relevant for processing plants, equipment manufacturers and governments and serve as a background to develop interventions. The results obtained in this thesis demonstrated that bacterial levels at the end of processing are affected by the initial bacterial contamination, which varies between incoming batches. Moreover they are affected by changes in the concentration of bacteria during processing that are specific for each slaughterhouse. Bacterial concentrations in excreta and caeca were the most prominent risk factors, because they were associated with concentration on carcasses at various processing steps. This thesis reveals for the first time, that processing hygiene may be affected by the practices of food handlers. The presence of that are visibly contaminated carcasses with faeces may be associated with compliance with prescribed procedures. As such carcasses carried higher E. coli concentrations, it suggests that compliance influences food safety. In the near future the European slaughterhouses may have to comply with a process hygiene criterion (PHC) for Campylobacter. To achieve this limit, they will need to implement improvements using technological solutions e.g. cleaning the exterior of carcasses at the first processing steps. This intervention was tested and was shown potential to diminish the bacterial concentration on carcasses. Further interventions could aim at minimising contamination during subsequent processing steps, especially during defeathering and evisceration. Slaughterhouses may also implement managerial interventions, such as revisions of procedures and measures to ensure the compliance of food handlers. A combination of both technological and managerial approaches might reduce the bacterial concentrations most efficiently. Different slaughterhouses might need different interventions because contamination patterns were found to differ between slaughterhouses. To determine which risk factors and measures are most relevant, slaughterhouses will need to monitor bacterial contamination throughout their processing line. This monitoring could be based on generic E. coli because similarities in the effect of processing steps have been identified between this organism and ESBL/AmpC producing E. coli and Campylobacter at most of the tested processing steps. Once the risk factors are determined, and interventions are in place, those might effectively reduce the levels of multiple hazards on broiler carcasses, thus contributing to public health protection.