Antibody responses in the serum and gut of chicken lines differing in cecal carriage of Salmonella enteritidis.

Salmonella frequently causes human foodborne infections. Contaminated products from poultry infected with Salmonella enteritidis are mainly involved. This serovar is able to colonize the gastrointestinal tract and generally produces a chronic asymptomatic carrier state in poultry, except in very young birds.

Reliable ELISAs showing differences between resistant and susceptible lines in hens orally inoculated with Salmonella Enteritidis.

Reliable ELISAs were investigated with the aim to select hen lines resistant to Salmonella Enteritidis and producing high levels of antibodies. In the first experiment, the relation between the humoral response and the bacteriological results was assessed on hens from the Y11 resistant line and the L2 susceptible line, orally inoculated with 10(8) CFU S. Enteritidis per animal.

Variability in the resistance of four chicken lines to experimental intravenous infection with Salmonella enteritidis phage type 4.

The capacity of four chicken lines (Y11, L2, B13, PA12) to control Salmonella enteritidis (SE) phage type 4 (PT4) systemic colonization was investigated. Thirteen-week-old chickens were intravenously inoculated with 10(6) SE colony-forming units, and the levels of SE colonization were determined at various time intervals after inoculation in liver, spleen, genital organs, and ceca. The course of SE infection showed a rapid contamination of liver, spleen, and genital organs, whereas the ceca were infected later.

Estimated heritability of the resistance to cecal carrier state of Salmonella enteritidis in chickens.

Previously, we have shown differences in susceptibility to the cecal carrier state in chicks orally infected with Salmonella enteritidis (SE) at 1 wk of age for four outbred lines: L2, B13, PA12, and Y11. The egg-type line L2 was one of the most susceptible lines and presented a large variability in cecal SE colonization. The heritability (h2) of the resistance to SE colonization in ceca was estimated in L2 chickens to determine whether genetic factors might be involved in its control.

Differences in frequency, level, and duration of cecal carriage between four outbred chicken lines infected orally with Salmonella enteritidis.

Four chicken lines, L2, B13, PA12 (egg-type), and Y11 (meat-type), were tested for experimental carrier state of Salmonella enteritidis (SE) in two identical trials. After oral inoculation of SE at 1 wk of age with 5 x 10(4) SE colony-forming units (CFU), 10 chickens per line were necropsied weekly for 6 wk and then every 8 or 15 days until the 12th week postinoculation (PI). Liver, spleen, ovary, and ceca were examined for level of SE colonization.