title: Salmonella Typhimurium and Salmonella Sofia: Growth in and Persistence on Eggs under Production and Retail Conditions.
abstract: 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 two Salmonella serotypes, an egg outbreak associated Salmonella Typhimurium and a non-egg-associated Salmonella enterica ssp. 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), with S. Typhimurium isolates attaching at higher levels (P < 0.05) than S. Sofia after 1 min at 4 °C and S. Typhimurium ATCC 14028 attaching at higher (P < 0.05) levels at 22 °C. Survival on egg shells was not significantly different across isolates. Salmonella serotypes behaved similarly regarding growth in egg contents, attachment to egg shells and survival on eggs, indicating that other factors more likely contributed to reasons for S. Typhimurium being implicated in multiple egg-associated outbreaks.
authors.affiliation: CSIRO Food and Nutrition, Private Bag 16, Werribee, VIC 3032, Australia.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: McAuley
authors.affiliation: CSIRO Food and Nutrition, P.O. Box 745, Archerfield BC, QLD 4108, Australia.
authors.forename: Lesley L
authors.initials: LL
authors.lastname: Duffy
authors.affiliation: Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC 3010, Australia.
authors.forename: Nela
authors.initials: N
authors.lastname: Subasinghe
authors.affiliation: Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC 3010, Australia.
authors.forename: Geoff
authors.initials: G
authors.lastname: Hogg
authors.affiliation: Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC 3010, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Coventry
authors.affiliation: CSIRO Food and Nutrition, Private Bag 16, Werribee, VIC 3032, Australia.
authors.forename: Narelle
authors.initials: N
authors.lastname: Fegan
mesh_terms: D000818:Animals; D004528:Egg Shell / Q000382:microbiology; D004531:Eggs / Q000382:microbiology*; D005516:Food Microbiology; D006801:Humans; D050296:Microbial Viability; D012480:Salmonella Infections / Q000382:microbiology; D019779:Salmonella enterica / Q000472:pathogenicity* / Q000502:physiology; D012486:Salmonella typhimurium / Q000472:pathogenicity* / Q000502:physiology