ABSTRACT
Small RNAs(sRNAs) play a significant role in the regulation of bacterial growth.When sensing certain environmental cues such as fluctuation of nutrient concentration, temperature, pH, and osmolarity, sRNAs can influence the expression of target genes.The formation of biofilms is initiated by bacteria transitioning from the planktonic to the surface-associated mode of growth, which is a self-produced extracellular matrix composed of proteins, polysaccharides, and DNA.Recent evidences have shown that small RNA plays an important role in the regulation of bacterial biofilm formation.sRNAs have key roles in biofilm formation process by base pairing with target mRNAs or interaction with modulating proteins.This review discussed the regulation mechanism and pathway of sRNAs in bacterial biofilms formation, and summarized three classical regulatory models of sRNAs in bacterial biofilms formation, this review also gives the research status and development direction of sRNAs in bacterial biofilms formation.
ABSTRACT
Objective To identify small non-coding RNAs encoded by plasmid pPCP1 and investigate their roles in biofilm formation, stress tolerance and/or virulence in Yersinia pestis.Methods Seven plasmid pPCP1-encoded sRNAs were identified by RNA-seq results in Y.pestis in our previous studies.Northern blot was used to validate the presence of the seven sRNAs.The sRNA-deletion mutants were constructed via λ-Red homologous recombination system.The biofilm formation, high salt tolerance and virulence of the phenotypes were compared between Y.pestis WT strain and sRNA mutants.Results and Conclusion The expression of seven pPCP1-encoded sRNAs was validated and the transcript length detected by Northern blotting corresponded to the length observed by RNA-seq.On this basis, five sRNA-deletion mutants were obtained.The capacity of biofilm formation was weakened upon deletion of sR3446.The tolerance of sR3446, sR3457, sR4338 and sR4340 mutants was found weakened in vitro compared to that of wild-type strain,but the tolerance of sR6143 was found increased.Slight virulence attenuation was found in two sRNA mutants ( sR4338 and sR4340 ) .The results suggest that pPCP1-deriving sRNA might be implicated in stress response, biofilm and virulence in Y.pestis.