Novel Non-Coding Small sRNA002 Targets the Virulence-Related Genes mrkA and mrkB of Carbapenem-Resistant Klebsiella pneumoniae.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a substantial public health threat worldwide. This trend is undoubtedly exacerbated by biofilm formation, which is closely related to bacterial virulence. Small RNAs (sRNAs) are post-transcriptional regulators of many biological processes in bacteria, including biofilm formation and virulence. The purpose of this study was to investigate the regulatory mechanisms of a novel sRNA (sRNA002) on biofilm formation and the virulence of CRKP. Through the CRISPR-Cas9 gene editing system, proteomic sequencing, real-time quantitative polymerase chain reaction (RT-qPCR), crystal violet staining, scanning electron microscopy, hydrophobicity assay, a mouse intraperitoneal infection model, and the green fluorescent protein reporter system, we confirmed that the knockout of sRNA002 significantly downregulated the expression of the mrkA and mrkB genes, and weakened the virulence and biofilm formation ability of CRKP.