For the study, investigators assessed the various routes that S. Heidelberg might infect broilers and eventually pose a food-safety risk. They inoculated birds either via the trachea, orally, the eyes, the cloaca or subcutaneously.

When comparing inoculation routes, the recovery of S. Heidelberg was greatest with tracheal exposure — 64% — compared to 32% for oral, 19% for ocular, 11% for cloacal and 10% for subcutaneous inoculation, reported Elle Chadwick, a graduate research assistant at Auburn University.

One thousand day-old chicks were used in this study, carried out at the university’s poultry farm. The chicks were inoculated with S. Heidelberg before placement on the farm.

The results indicate that inhalation of S. Heidelberg-contaminated particles and dust can increase colonization of the pathogen, she said.

Chadwick and colleagues also sought to determine the best organs to sample for S. Heidelberg and found the ceca yielded the highest recovery as compared to crop or cloacal swabs.

The poultry industry lacks a standardized sampling method for S. Heidelberg at the pre-harvest level, and the results of this research can help point the way to the establishment of such a method, Chadwick said.

1. Chadwick E, et al. Environmental influences of Salmonella Heidelberg colonization in commercial broilers. 2017 International Poultry Scientific Forum. Atlanta, Georgia.