The Detection of Enteritidis on German Layer Farms after Cleaning and Disinfection.

The presence of Enteritidis in poultry houses after cleaning and disinfection can pose a potential risk to public health, as remains one of the most important causes of foodborne diseases. This study focused on ten German layer farms (including floor-reared and free-range systems) with a recent history of Enteritidis, and samples were collected from July 2018 to March 2021 after the cleaning and disinfection process. A total of 244 swab samples were tested for the presence of using real-time PCR, followed by a culture of positive samples. Results revealed that 61 out of the 244 swab samples tested positive for , indicating a prevalence of 25% in the samples examined. Among the -positive swab samples identified with the PCR assay, 65.6% (40 out of 61) were confirmed by the culture. Of the 40 isolates obtained from the culture, 36 were identified as Enteritidis, while 4 were categorized as rough strains. This study emphasizes the importance of both the surrounding area of the poultry houses in terms of infection carry-over and the meticulous implementation of cleaning and disinfection procedures to eliminate any remaining infection within the houses. To mitigate the risk of further spread on layer farms, additional investigations are recommended to focus on the existing transmission pathways of and their genetic diversity.