Effect of Bacteriophage Application on Campylobacter jejuni Loads in Commercial Broiler Flocks

Abstract

ABSTRACTCampylobacteriosis is the most frequent food-borne human enteritis. The major source for infection withCampylobacterspp. is broiler meat. Risk assessments consider the reduction ofCampylobacterin primary production to be most beneficial for human health. The aim of this study was to test the efficacy of a bacteriophage application under commercial conditions which had proved to be effective in previous noncommercial studies under controlled experimental conditions. A phage cocktail forCampylobacterreduction was tested on three commercial broiler farms each with a control and an experimental group. Colonization ofCampylobacterwas confirmed prior to phage application in fecal samples. Subsequently, a phage cocktail was applied via drinking water in the experimental group (log105.8 to 7.5 PFU/bird). One day after phage application,Campylobactercounts of one experimental group were reduced under the detection limit (<50 CFU/g,P= 0.0140) in fecal samples. At slaughter, a significant reduction of >log103.2 CFU/g cecal content compared to the control was still detected (P= 0.0011). No significant reduction was observed in the experimental groups of the other trials. However, a significant drop in cecalCampylobactercounts occurred in a phage-contaminated control. These results suggest that maximum reduction ofCampylobacterat the slaughterhouse might be achieved by phage application 1 to 4 days prior to slaughter.