Invasion of Chicken Reproductive Tissues and Forming Eggs Is Not Unique to Salmonella enteritidis

Abstract

Experiments were conducted in which Salmonella enteritidis Phage Type 8, Phage Type 2, and RDNC (reaction does not conform) or three isolates of Salmonella typhimurium of diverse origin were fed to adult laying hens to determine if S. enteritidis has a selective advantage over S. typhimurium, which is now rarely isolated from chicken eggs, in its capacity to invade reproductive tissues. The results revealed that S. enteritidis and S. typhimurium may be equal in their potential to colonize the tissues of the reproductive tract and eggs that are forming in the oviduct prior to oviposition. S. enteritidis, but not S. typhimurium, was isolated from egg contents after oviposition. The degree to which intestinal, hepatic, splenic, or reproductive tissues were colonized by either serotype was not seen to affect the rate of colonization of eggs forming in the oviduct or the contamination of eggs after oviposition. Virulence factors related to the difference in the association of S. enteritidis and S. typhimurium with egg-borne salmonellosis remain to be defined.

Characteristics of Persistent Salmonella Enteritidis Strains in Two Integrated Broiler Chicken Operations of Korea

“…Vertical transfer of infections from breeding hens to progeny has been an important aspect of the epidemiology of Salmonella species infections within the poultry industry [1,7,8,12,30].…”

Scientific Opinion on the public health risks of table eggs due to deterioration and development of pathogens

“…As the follicles are particularly rich in nutrients, Salmonella grows extensively in them at a chicken body temperature of 42 °C, and this can lead to degeneration of the contaminated follicle before the production of the egg (Gantois et al, 2009). In studies involving experimental infections of laying hens, the presence of Salmonella in the ovaries did not necessarily correspond to the production of contaminated egg contents (Barrow and Lovell, 1991;Keller et al, 1997).…”

“…Studies have shown that some S. Enteritidis phage types (PTs) are more invasive than others (Hinton et al, 1990;Roy et al, 2001), but other similarly designed studies could not identify any difference in the invasiveness or colonisation ability between different phage types (Barrow, 1991). Despite its peculiar affinity for the reproductive tract of hens, S. Enteritidis is not the only serotype able to colonise ovaries and oviducts and contaminate forming eggs (Keller et al, 1997;Okamura et al, 2001a;Gast et al, 2004;Gantois et al, 2008).…”

“…Other S. Typhimurium DTs, such as DT104 and DT49, can infect chickens and cause egg contamination Williams et al, 1998;Okamura et al, 2010). The virulence and invasiveness of S. Typhimurium are also determined by the bacterial strain (Barrow et al, 1987;Keller et al, 1997;Okamura et al, 2010;Wales and Davies, 2011). For example, a study investigating the invasiveness and egg contamination potential of 10 S. Typhimurium DT104 strains has shown that they differed in their ability to cause ovarian infection and egg contamination (Okamura et al, 2010).…”

“…Several studies have demonstrated that Salmonella can colonize the reproductive tract and colonize eggs (Gast, 1994;Keller et al, 1997;Okamura et al, 2001a;Okamura et al, 2001b).…”