Multi-omics Analysis of Klebsiella pneumoniae Revealed Opposing Effects of Rutin and Luteolin on Strain Growth.

The emergence of pathogenic bacteria resistant to conventional antibiotics is becoming increasingly challenging. Plant-derived flavonoids are potential alternatives to antibiotics, owing to their antimicrobial properties. However, the molecular mechanisms through which they inhibit the growth of pathogenic microorganisms remain unclear. Therefore, Klebsiella pneumoniae ATCC700603 was separately incubated in two flavonoids to elucidate their inhibitory mechanism. Metabolomic and transcriptomic analyses were performed after 4-h incubation. In total, 5483 genes and 882 metabolites were identified. Compared to the untreated control, rutin and luteolin activated 507 and 374 differentially expressed genes (DEGs), respectively. However, the number of differential abundant metabolites (DAMs) remained the same. The top 10 correlated DEGs and DAMs were identified within each comparative group after a correlation analysis. Rutin induced the accumulation of unique metabolites and suppressed gene expression whereas luteolin did not. Our results explain the disparate effects of these two flavonoids and demonstrate the inhibitory mechanism of rutin on strain growth.