Submitted to: Western Poultry Disease Conference
Publication Type: Proceedings
Publication Acceptance Date: 11/18/2009
Publication Date: 3/1/2010
Citation: Holt, P.S., Vaughn, L.E., Gast, R.K., Anderson, K.E. 2010. Comparing in vitro lymphocyte reactivity to Salmonella enterica serovar Enteridis (SE) antigens 5 commercial white egg and 3 commercial brown egg strains of laying hens following SE infection. Western Poultry Disease Conference. p. 107. Interpretive Summary:
Technical Abstract: Different chicken breeds have been shown to exhibit varying susceptibility to infection with paratyphoid salmonellae. The current study was undertaken to compare the course of infection with SE in crops and intestines of 5 commercial white egg strains (W1-W5) and 3 commercial brown egg strains (B1-B3) of laying hens and attempt to correlate these infections with the ability of lymphocytes from the infected hens to respond to respond in vitro to SE lipopolysaccharide (LPS) and SE flagella. Hens were orally challenged with 108 SE and crop lavage and fecal samples were collected weekly. Weeks 2 and 4 post infection (PI), 5 hens from each strain were sacrificed, spleens removed, splenocytes purified and incubated with LPS or flagella, and proliferation measured 72 hours later. All of the white egg hens were 80-100% crop SE positive at one and two weeks PI and then levels decreased thereafter. This is in contrast to hen strain B3 and B1 which were 20% and 40% crop positive, respectively. However, examination of fecal shedding showed that all strains of hens were similar, with 80-100% of all the hens exhibiting fecal SE at week 1 PI. Lymphocyte response to LPS and flagella were generally low at week 2 PI and strongly increased at week 4. Hen strain W4, however, exhibited high lymphocyte activity to both antigens prior to infection and this increased 2 weeks PI before decreasing at week 4. This high activity did not appear to impact crop or intestinal SE colonization as both sites were 100% SE+ at 1 week PI. The hen strain that exhibited low crop SE colonization, B3, responded strongly in vitro to both antigens and exhibited the highest response of all the strains at week 4 PI. These results indicate that different hen strains vary in their crop colonization by SE but this cannot be extended to gut colonization. The highest specific in vitro response to SE antigen was observed in lymphocytes taken from the hen strain that exhibited the lowest crop SE colonization but more studies need to be conducted before any conclusions can be drawn from these observations.