Transcriptome Analysis of the Cecal Tonsil of Jingxing Yellow Chickens Revealed the Mechanism of Differential Resistance to Salmonella.

Fei Wang,Qinghe Li,Jie Wang,Bo Zhu,Qiao Wang,Jin Zhang,Jie Wen,Guiping Zhao,Maiqing Zheng

doi:10.3390/genes10120979

Abstract

Salmonella is one of the most common food-borne pathogens. It can be transmitted between chickens, as well as to people by contaminated poultry products. In our study, we distinguished chickens with different resistances mainly based on bacterial loads. We compared the cecal tonsil transcriptomes between the susceptible and resistant chickens after Salmonella infection, aiming to identify the crucial genes participating in the antibacterial activity in the cecal tonsil. A total of 3214 differentially expressed genes (DEGs), including 2092 upregulated and 1122 downregulated genes, were identified between the two groups (fold change ≥ 2.0, padj < 0.05). Many DEGs were mainly involved in the regulation of two biological processes: crosstalk between the cecal tonsil epithelium and pathogenic bacteria, such as focal adhesion, extracellular-matrix–receptor interaction, and regulation of the actin cytoskeleton and host immune response including the cytokine–receptor interaction. In particular, the challenged resistant birds exhibited strong activation of the intestinal immune network for IgA production, which perhaps contributed to the resistance to Salmonella infection. These findings give insight into the mRNA profile of the cecal tonsil between the two groups after initial Salmonella stimulation, which may extend the known complexity of molecular mechanisms in chicken immune response to Salmonella.

Highlights

Salmonella is an important cause of food-borne and zoonotic disease, which can colonize in chickens
To choose that candidate individuals of the chickens for RNA sequencing (RNA-seq), the liver bacterial load was measured by counting the number of colonies on the MacConkey agar
Apart from clinical symptoms, the bacterial burden in the livers and the lysozyme content in the serum were taken into consideration to evaluate the susceptibility and the lysozyme content in the serum were taken into consideration to evaluate the susceptibility and resistance of the chickens

Summary

Introduction

Salmonella is an important cause of food-borne and zoonotic disease, which can colonize in chickens. It poses a serious threat to people’s health via the consumption of contaminated meat and eggs [1]. Many measures have been taken to reduce salmonellosis during poultry production, including the improvement of the breeding environment, sterilization and vaccination [2]. Cases of salmonellosis happen occasionally [3]. New efficient and permanent strategies are necessary to control this disease. These strategies require an understanding of the interaction between chickens and bacteria

Results

Discussion

Conclusion