Quorum sensing inhibition and tobramycin acceleration in Chromobacterium violaceum by two natural cinnamic acid derivatives.

Quorum sensing inhibition and tobramycin acceleration in Chromobacterium violaceum by two natural cinnamic acid derivatives. Appl Microbiol Biotechnol. 2020 Apr 04;: Authors: Cheng WJ, Zhou JW, Zhang PP, Luo HZ, Tang S, Li JJ, Deng SM, Jia AQ Abstract Chromobacterium violaceum, one free-living Gram-negative bacterium, is abundantly presented in tropics and sub-tropics soil and aquatic environment; it is also an opportunistic human pathogen. Here, two cinnamic acid derivatives, i.e., 4-dimethylaminocinnamic acid (DCA) and 4-methoxycinnamic acid (MCA), were identified as potential quorum sensing (QS) and biofilm inhibitors in C. violaceum ATCC12472. Both DCA (100 μg/mL) and MCA (200 μg/mL) inhibited the levels of N-decanoyl-homoserine lactone (C10-HSL) and reduced the production of certain virulence factors in C. violaceum, including violacein, hemolysin, and chitinase. Metabolomics analysis indicated that QS-related metabolites, such as ethanolamine and L-methionine, were down-regulated after treatment with DCA and MCA. Quantitative real-time polymerase chain reaction (qRT-PCR) demonstrated that DCA and MCA markedly suppressed the expression of two QS-related genes (cviI and cviR). In addition, DCA and MCA also inhibited biofilm formation and enhanced the susceptibility of biofilms to tobramycin, which was evidenced by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Our results indicated that DCA ...
Source: Applied Microbiology and Biotechnology - Category: Microbiology Authors: Tags: Appl Microbiol Biotechnol Source Type: research