Quantification of Salmonella Infantis transfer from transport drawer flooring to broiler chickens during holding

Authors: REINA, MARCO - Auburn University; MCCONNELL, ABIGAIL - Auburn University; FIGUEROA, JUAN - Auburn University; RIGGS, MONTANA - Auburn University; Buhr, Richard - Jeff; PRICE, STUART - Auburn University; MACKLIN, KENNETH - Auburn University; BOURASSA, DIANNA - Auburn University

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/12/2023
Publication Date: 11/20/2023
Citation: Reina, M.A., Mcconnell, A., Figueroa, J.C., Riggs, M.R., Buhr, R.J., Price, S.B., Macklin, K.S., Bourassa, D.B. 2023. Quantification of Salmonella Infantis transfer from transport drawer flooring to broiler chickens during holding. Poultry Science. 103(2). Article 10377. https://doi.org/10.1016/j.psj.2023.103277.
DOI: https://doi.org/10.1016/j.psj.2023.103277

Interpretive Summary: Transportation is a potential point of cross-contamination before broiler chickens arrive at the processing plant for slaughter. Previous studies have associated using uncleaned transport containers with the introduction of pathogenic bacteria onto uncontaminated chickens. The objective of this study was to quantify the transfer of Salmonella from transport drawer flooring to chickens during different holding times. For traceability, the flooring of each drawer was inoculated with Salmonella in feces. Three drawers per treatment were used, and each drawer was subjected to one of the following treatments: pressure wash, disinfectant, and pressure wash (A), pressurized steam followed by forced hot air (B), or no cleaning (C). Drawers were classified as top, middle, or bottom based on their relative position with each other. After treatment, chickens were introduced to each drawer and held for 2, 4, or 6 h. At each timepoint, chickens were removed from drawers, euthanized, and carcasses rinsed to obtain Salmonella counts. Samples under the limit of direct plating detection were enriched, plated, and later confirmed positive or negative. Differences were observed per treatment, holding time, and drawer relative position. Chickens placed in transport containers that underwent a cleaning procedure (A or B) had lower levels of Salmonella when compared to broilers placed in non-cleaned containers. However, most of the samples under the limit of detection were positive after enrichment, indicating that both procedures evaluated need improvement for efficient pathogen inactivation. A decrease in Salmonella transfer was observed after 6 h in rinsates obtained from broilers placed in non-cleaned containers (C). Rinsates obtained from top drawers had less Salmonella than the middle or bottom drawers when broilers were placed in transport containers that underwent a cleaning procedure (A and B). The application of pressurized steam and forced hot air was comparable to the use of water washes and disinfectant indicating a potential role in cleaning poultry transport containers.

Technical Abstract: Transportation is a potential point of cross-contamination before broiler chickens arrive at the processing plant for slaughter. Previous studies have associated the use of uncleaned transport containers with the introduction of pathogenic bacteria onto uncontaminated broilers. The objective of this study was to quantify the transfer of Salmonella from transport drawer perforated flooring to broiler chickens during different holding times. For traceability, the flooring of each drawer was inoculated with fecal content slurry containing a marker strain of Salmonella Infantis. Three drawers per treatment were used, and each drawer was subjected to one of the following treatments: pressure wash, disinfectant, and pressure wash (A), pressurized steam followed by forced hot air (B), or no cleaning (C). Drawers were classified as top, middle, or bottom based on their relative position with each other. After treatment, broilers were introduced to each drawer and held for 2, 4, or 6 h. At each timepoint, broilers were removed from drawers, euthanized, and carcasses rinsed to obtain Salmonella counts. Samples under the limit of direct plating detection were enriched, plated, and later confirmed positive or negative. Differences were observed per treatment, holding time, and drawer relative position (P<0.0001). Broilers placed in transport containers that underwent a cleaning procedure (A or B) had lower levels of Salmonella when compared to broilers placed in non-cleaned containers. However, most of the samples under the limit of detection were positive after enrichment, indicating that both procedures evaluated need improvement for efficient pathogen inactivation. A decrease in Salmonella transfer was observed after 6 h in rinsates obtained from broilers placed in non-cleaned containers (C). Rinsates obtained from top drawers had less Salmonella than the middle or bottom drawers when broilers were placed in transport containers that underwent a cleaning procedure (A and B). The application of pressurized steam and forced hot air was comparable to the use of water washes and disinfectant indicating a potential role in cleaning poultry transport containers.