Effect of Moisture and Temperature on Ability of Salmonellae to Infect Shell Eggs

Human salmonellosis is one of today’s major public health problems. Shell eggs have sometimes been responsible for food borne outbreaks of this illness (Philbrook et al., 1960; Bowmer, 1965 ; Adler, 1965). It is important that the means by which Salmonellae infect the egg be understood and prevented. For the purpose of this paper, the word “infect” shall mean to invade and proliferate in the egg contents to more than 1,000 viable cells per gram. Although Salmonellae can enter the egg from an infected ovary (Van Roekel, 1965; Board, 1966), the most common route of infection is considered to be by penetration through the shell (Mundt and Tugwell, 1958; Adler, 1965). The ability of Salmonellae to invade the egg shell has been demonstrated by Bigland and Papas (1953), Stokes et al. (1956), Brown et al. (1965), Rizk et al. (1966) and others.…