7:1,7,8 WITHIN TURKEY HATCHING EGGS

SUMMARY After incubation for ten days, embryonated turkey eggs were infected with Arizona 7:1,7,8. Injection of a penicillin-streptomycin mixture or spectinomycin several days prior to artificial infection failed to protect the eggs, and injection of dihydrostreptomycin, kanamycin, penicillin-streptomycin, or spectinomycin two days after infection failed to destroy the arizona in ovo. Such antibiotic treatments cannot be recommended for the eradication of arizonae in turkey hatching eggs. Drug levels were detectable in blended embryonated eggs throughout the incubation period, although arizona cultures reisolated from embryos and poults demonstrated little resistance to the test antibiotics. The concurrent use of tetrathionate broth at 35 C and selenite F broth at 43 C for 48 hr yielded significantly more isolations than were obtained from either medium separately (P<0.01).