Comparative study of Salmonella enterica serovar Enteritidis genes expressed within avian and murine macrophages via selective capture of transcribed sequences (SCOTS)
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Salmonella enterica serovar Enteritidis (SE) is a communicable zoonotic bacterium. Macrophages are essential for Salmonella survival, transmission, and infection. In this study, selective capture of transcribed sequences (SCOTS) was used to screen genes preferentially expressed by SE during contact with macrophages from different hosts. We found 57 predicted genes and 52 genes expressed by SE during interaction with avian HD-11 and murine RAW264.7 cells, respectively. These expressed genes were involved in virulence, metabolism, stress response, transport, regulation, and other functions. Although genes related to survival or metabolic pathways were needed during SE infection, different gene expression profiles of SE occurred in the two macrophage cell lines. qRT-PCR results confirmed that most screened genes were upregulated during infection in contrast to the observation during in vitro cultivation, with different expression levels in infected avian macrophages at 2-h and 7-h post-infection. In addition, in vitro and in vivo competition assays confirmed that SEN3610 (a putative deoR family regulator) and rfaQ (related to LPS synthesis) were closely related to SE virulence in both mice and chickens. Three putative transcriptional regulators, SEN2967, SEN4299, and rtcR, were related to SE colonization in mice, while the ycaM mutation caused decreased infection and survival of SE in HD-11 cells without influencing virulence in mice or chicken. Genes showing differential expression between SE-infected avian and murine macrophages indicate specific pathogen adaptation to enable infection of various hosts.
KeywordsSalmonella enterica serovar Enteritidis (SE) Macrophage HD-11 RAW264.7 Gene expression profile
We thank all of the staffs for their helpful suggestions and work during this project. We would like to thank the editor for the helpful comments on the manuscript.
Qiuchun Li and Yu Yuan contributed equally to this article.
This work was funded by the National Natural Science Foundation of China (31320103907, 31730094), the Special Fund for Agro-scientific Research in the Public Interest (201403054), the National Key Research and Development Program of China (2017YFD0500705,2017YFD0500105); the Jiangsu Province Agricultural Science and Technology Independent Innovation Funds (CX(16)1028), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All animal experiments were approved by the Jiangsu Administrative Committee for Laboratory Animals (Approval No. SYXK 2016-0020) and conducted in accordance with the guidelines approved by Yangzhou University’s Institutional Animal Care and Use Committee. This article does not contain any studies with human participants performed by any of the authors.
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