REDUCTION OF FECAL SHEDDING AND EGG CONTAMINATION OF SALMONELLA-ENTERITIDIS BY INCREASING THE NUMBER OF HETEROPHIL ADAPTATIONS

Serial passage of Salmonella enteritidis (SE) in chicken heterophils r esulted in heterophil-adapted SE (HASE). We now report that an additio nal five heterophil passages have further reduced the number and frequ ency of fecal shedding of HASE. Eleven-times HASE (11x HASE) given to 12 laying hens for three consecutive days reduced fecal shedding of 11 x HASE to three isolations from fecal samples during the 70-day postex posure observation period. Hens were exposed to challenge SE 74 days a fter treatment with 11x HASE. Three of 12 11x HASE-treated hens were p ositive for challenge SE (11/396 fecal samples, or 2.8%) between days 5 and 40 postchallenge, whereas all 12 challenge control birds were po sitive (118/420 fecal samples, or 28.1%) for SE. None of 12 11x HASE-t reated hens was fecal positive from day 9 postchallenge, whereas 10 of 12 challenge control hens (82/372 fecal samples, or 22.0%) remained p ositive until day 40, the termination of the experiment. None of 525 e ggs and eggshells cultured after 11x HASE exposure was positive for Sa lmonella, and none of 422 eggs and eggshells cultured after challenge SE exposure was positive for Salmonella. Eggs or eggshells from challe nge control hens were positive for Salmonella in 12/479 (2.5%) cases a fter challenge SE exposure.