The Small Non-coding RNA Contributes to the Environmental Adaptation and Pathogenicity of .

INTRODUCTION

(LM) is an important food-borne pathogen, and the risk of its ingestion is a serious public health issue. The better its environmental adaptation mechanisms and pathogenicity are understood, the better the risk it poses can be countered. The regulatory role of the small non-coding RNA (sRNA) in the environmental adaptation and pathogenicity of LM is still unclear and this study investigated that role through its biological function.

MATERIAL AND METHODS

An LM- gene deletion strain and an LM- gene complementation strain were constructed using the homologous recombination technique. Then, the adaptation of these strains to temperature, alkalinity, acidity, salinity, ethanol and oxidative stressors, their biofilm-forming ability and their pathogenicity in mice were investigated to show the regulatory roles of sRNA in LM. The target gene of was also predicted, and the interaction between it and was verified by a two-plasmid co-expressing system based on and Western blot analysis.

RESULTS

The adaptation of LM- to environmental stressors of pH 9, 5% NaCl and 8% NaCl, 3.8% ethanol and 5 mM HO was significantly reduced when compared to the parental (LM EGD-e) and complementation strains. Also, the biofilm formation, cell adhesion, invasion, intracellular proliferation and pathogenicity of LM- in mice were significantly reduced. The results of two-plasmid co-expression and Western blot showed that can interact with the mRNA of the predicted target gene.

CONCLUSION

The sRNA may positively regulate the expression of the gene in LM. This study sheds light on its regulatory roles in environmental adaptation and pathogenicity, providing new insights into the molecular mechanism of sRNA mediation in LM .