Abstract
Human cases of salmonellosis are frequently liked with the consumption of contaminated table eggs. Recently, there has been an increase in consumer demand for cage-free eggs precipitating the need for a greater understanding of Salmonella dynamics in free-range production systems. A longitudinal study was conducted to determine the points in production where birds are most likely to be exposed to Salmonella and where the risk of egg contamination is highest. In this study, two free-range flocks were sampled from hatch to the end of production. At hatch, all chicks were Salmonella negative and remained negative during rearing. During production, the proportion of positive samples was low on both farms. Salmonella positive samples were detected intermittently for Flock A. Dust, nest box, and egg belt swabs had the highest proportion of positive samples and highest overall loads of Salmonella. The egg grading floor was swabbed at different points following the processing of eggs from Flock A. Only the suction cups that handle eggs prior to egg washing tested positive for Salmonella. Swabs collected from machinery handling eggs after washing were Salmonella negative. During production, positive samples from Flock B were observed at only single time point. Dust has been implicated as a source of Salmonella that can lead to flock to flock contamination. Bulk dust samples were collected and tested for Salmonella. The proportion of positive dust samples was low and is likely due to physical parameters which are not likely to support the survival of Salmonella in the environment.
Highlights
Salmonella in the food supply chain represents a significant public health threat
While many food items can become contaminated with Salmonella, raw eggs and foods containing raw eggs are frequently identified as the bacterial source during trace back epidemiological investigation of human salmonellosis [2, 3]
Prevalence of Salmonella during rearing Flock A was reared on the floor and pre-population litter and dust samples all tested negative for Salmonella
Summary
Non-typhoidal Salmonella enterica serotypes have been estimated to cause over 80 million cases of foodborne human gastrointestinal disease worldwide [1]. Due to the implementation of strict egg safety regulations, the total number of egg related cases of salmonellosis has been decreasing in the US and UK [4]. In Australia, during the period spanning 2000–2013, a steady increase in the number of egg-related salmonellosis has been observed [3, 5, 6]. S. Enteriditis has not been widely detected on Australian commercial egg farms and human infection with this serotype has been predominantly linked epidemiologically with overseas travel [9]. S. Typhimurium definitive types (DT) are most commonly isolated during outbreak investigation of Australian egg-related cases of salmonellosis [5, 7]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
