gene involved in curli amyloids and fimbriae production in : exploring pathways to inhibit biofilm and amyloid formation.

Background: Biofilm formation is a complex phenomenon of bacterial cells, involved in several human infections. Its formation is regulated and controlled by several protein factors. The BolA-like proteins ( gene) are conserved in both prokaryotes and eukaryotes. The BolA protein is a transcription factor involved in bacterial cell motility and biofilm formation. This study was initiated to elucidate the role of the gene in the curli biogenesis and amyloid production as well as to observe changes in the expression of , a fimbriae gene.

Methods: Knockdown mutants of MG1655 gene - were generated using CRISPR interference. The results obtained, were validated through gene expression using RT-PCR, microscopic analysis and different biofilm and amyloid assays.

Results: The knockdown mutants showed a decrement in curli amyloid fibers, in fimbriae production and biofilm formation. We have also observed a reduction in EPS formation, eDNA production and extracellular protein content. Gene expression data showed that downregulation caused the suppression of and of curli that led to the reduction in curli fiber and the amyloid formation and also the suppression of , leading to the loss of fimbriae.

Conclusions: Curli fibers and fimbriae are found to be involved in biofilm formation leading to the pathogenicity of the bacterial cell. BolA is a conserved protein and is found to play a significant role in curli and fimbriae formation in This study further proved that CRISPRi mediated suppression of the A gene leads to inhibition of biofilm formation through curli and fimbriae inhibition. Hence, it may be proposed as a possible target for intervention of biofilm mediated infections.