SalmonellaTyphimurium andSalmonellaSofia: Growth in and Persistence on Eggs under Production and Retail Conditions

摘要

Salmonellosis in Australia has been linked to eggs and egg products with specific serotypes associated with outbreaks. We compared attachment to and survival on egg shells and growth in eggs of twoSalmonellaserotypes, an egg outbreak associatedSalmonellaTyphimurium and a non-egg-associatedSalmonella entericassp. II 1,4,12,27:b:[e,n,x] (S. Sofia). Experiments were conducted at combinations of 4, 15, 22, 37 and 42°C. No significant differences occurred between the serotypes in maximum growth rates, which were significantly greater (P<0.001) in egg yolk (0.427 log10 CFU/mL/h) compared to whole egg (0.312 log10 CFU/mL/h) and egg white (0.029 log10 CFU/mL/h). Attachment to egg shells varied by time (1 or 20 min) and temperature (4, 22 and 42°C), withS. Typhimurium isolates attaching at higher levels (P<0.05) thanS. Sofia after 1 min at 4°C andS.Typhimurium ATCC 14028 attaching at higher (P<0.05) levels at 22°C. Survival on egg shells was not significantly different across isolates.Salmonellaserotypes behaved similarly regarding growth in egg contents, attachment to egg shells and survival on eggs, indicating that other factors more likely contributed to reasons forS.Typhimurium being implicated in multiple egg-associated outbreaks.