Investigation of the Potential of Aerosolized Salmonella Enteritidis on Colonization and Persistence in Broilers from D 3 to 21

Authors: PAL, AMRIT - Auburn University; RIGGS, MONTANA - Auburn University; OSBORNE, RACHEL - Auburn University; GIRON, ANDREA - Auburn University; JACKSON, ALLY - Auburn University; BAILEY, MATTHEW - Auburn University; MACKLIN, KEN - Auburn University; PRICE, STUART - Auburn University; Buhr, Richard - Jeff; BOURASSA, DIANNA - Auburn University

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/7/2021
Publication Date: 7/19/2021
Citation: Pal, A., Riggs, M.R., Osborne, R., Giron, A., Jackson, A., Bailey, M.A., Macklin, K.S., Price, S.B., Buhr, R.J., Bourassa, D.V. 2021. Investigation of the Potential of Aerosolized Salmonella Enteritidis on Colonization and Persistence in Broilers from D 3 to 21. Poultry Science Association. Meeting Abstract.

Interpretive Summary: n/a

Technical Abstract: The presence of Salmonella in air of poultry houses has been confirmed through published research. Therefore, it is important to investigate the transmission of Salmonella to chickens via air. The present study aimed to evaluate the potential of different doses of aerosolized Salmonella Enteritidis inoculation, in day-old broilers, on colonization of ceca, liver/spleen, and trachea of broilers over time. For each of the three independent trials, a total of 112 1-d old birds were randomly divided into four groups (n=28/group). On d 1 of bird age, group 1 (control) was exposed to aerosolized sterilized saline and remaining groups were exposed to one of three doses, 10^3 CFU/mL (group 2), 10^6 CFU/mL (group 3), 10^9 CFU/mL (group 4), of aerosolized Salmonella Enteritidis. Aerosolized exposure time was 30 min/group and was performed using a nebulizer. Nebulizer generated aerosol particles were <5 µm and the average nebulizing rate was 0.20 mL/min. Following nebulization, birds were reared in separate battery cages up to 21 d of age. On d 3, 7, 14, and 21 of age, ceca, liver/spleen, and trachea of 6 birds/group/trial were aseptically removed following euthanasia. Tissues were cultured for Salmonella prevalence and ceca for Salmonella counts (log10 CFU/g). Salmonella counts were analyzed by two-way ANOVA with Tukey’s HSD for means separation. Prevalence data were analyzed using Fisher’s exact test. All sampled tissues from the control group were Salmonella negative. On sampling d 3 and 7, ceca Salmonella counts were highest from group 4 (5.14 and 5.11, P=0.0281). No differences for Salmonella counts were observed among groups on d 14 or 21 (P=0.5666). In group 2, ceca Salmonella counts increased (P=0.0188) from d 3 (2.43) to d 7 (4.43) and then remained constant. Ceca Salmonella counts decreased over time for groups 3 and 4 (P = 0.0005, 4.56 to 2.59 group 3, 5.14 to 2.81 group 4). For each tissue, Salmonella prevalence increased with increasing inoculum levels at all sampling timepoints (P=0.0213). Salmonella prevalence was low (0/18 to 4/18) and did not change over time in sampled tissues for group 2 (P=0.2394). For groups 3 and 4, Salmonella prevalence decreased over time in ceca (17/17 to 8/18 group 3, 18/18 to 12/18 group 4) and liver/spleen (17/18 to 5/18 group 3, 18/18 to 14/18 group 4) (P=0.0483). For group 4, trachea prevalence increased from d 3 (11/18) to d 14 (18/18) and then decreased at d 21 (10/18) (P=0.0015). Overall, this study demonstrated Salmonella colonization and persistence in chickens following aerosol inoculation is dependent on Salmonella challenge levels and sample time post exposure.