Alteredyersinia Pestisvirulence Is Associated With The Small Regulatory Rna Hmsa Encoded On The Plasmid Ppcp1

Aim:The aim of this study was to access the effect of HmsA, a 65-nt small regulatory RNA encoded by the pPCP1 plasmid, onYersinia pestisvirulence.Materials & methods:Survival and the competition index were determined in mice infected with wild-type Y. pestisand anhmsAdeletion mutant. RNA-seq was used to identify HmsA-regulated genes.Results:HmsA deletion enhancedY. pestisvirulence. However, there was no overlap between 18 upregulated genes associated with pathogenicity and potential direct HmsA targets, based on gene expression screening after HmsA-pulse overexpression.Conclusion:HmsA inhibitsY. pestisvirulence, but this effect may be mediated by indirect effects on pathogenesis, iron homeostasis and/or other cellular processes.