Thesis (Ph.D.) - Cairo University - Faculty of Veterinary Medicine- Department of Animal Diseases

Cronobacter sakazakii (C.sakazakii) 94 isolates were identified from 800 collected samples (11.75%). C.sakazakii inoculation to SPF chicken embryos infected by dipped or Intra-yolk; each with 1.5 {u00D7}108 cfu/ml. where 20% or 50% of embryos were died after 24 hr.; respectively. The reared obtained chicks after hatching showed mortality rate 12.5% or 30%. C.sakazakii was reisolated from all dead embryos and chicks. Clinical signs on survival chicks were dullness, depression, sleepy, ruffled feather and diarrhea. Gradual developed diarrhea to become brownish .Intermittent shedding of C sakazakii in dropping was confirmed.C.sakazakii infection to 1-day old SPF chicks raveled that s.c infected chicks showed 50% mortality at the 1st day post infection (3rd day of age) and 20% mortality at 6th day of age . The Intra-crop infected chicks showed 20% mortality at the 1st day of infection and 12.5% at 7th day of age. Two weeks native breed chick{u2019}s s.c injected or infected orally mortality rate was 12.5% or 9.2%; respectively. Infection with C.sakazakii decrease weekly BWG, main weekly BW and FCR than control. Total FCR it was found that s.c, intra- crop show lower values (1.84 and 1.79) than control (1.75). Enrofloxacin and /or hydroenzyme can be used to control C.sakazakii in infected chicks and reduce signs, mortalities, and histopathological lesions and improve FCR

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