Molecular Basis for Luteolin as a Natural TatD DNase Inhibitor in Trueperella pyogenes

Abstract

TatD960 and TatD825 are DNases that contribute to biofilm formation and virulence in Trueperella pyogenes (T. pyogenes). Luteolin is a natural flavonoid commonly found in plants that exhibits antimicrobial capacity. Our study aims to investigate the effects of luteolin on TatD DNases as a natural inhibitor. In this research, the expression of tatD genes and TatD proteins in T. pyogenes treated with luteolin was detected, and then the effect of luteolin on the hydrolysis of DNA by TatD DNases was analyzed using agarose gel electrophoresis. Moreover, the interactions between luteolin and TatD DNases were tested using surface plasmon resonance (SPR) assays and molecular docking analysis. After 1/2 MIC luteolin treatment, the transcription of tatD genes and expression of TatD proteins appeared to be reduced in 80–90% of T. pyogenes (n = 20). The gel assay revealed that luteolin can inhibit the activity of TatD DNases. The SPR assay showed that the KD values of luteolin to TatD960 and TatD825 were 6.268 × 10−6 M and 5.654 × 10−6 M, respectively. We found through molecular docking that hydrogen bonding is predominant in the interaction of luteolin and TatD DNases. Our data indicate that luteolin inhibited the ability of TatD DNases by decreasing their binding to DNA. The current study provides an insight into the development of luteolin as a DNase inhibitor in preventing biofilm formation and virulence in T. pyogenes.

Molecular Characterization of Resistance and Virulence Factors of Trueperella pyogenes Isolated from Clinical Bovine Mastitis Cases in China

“…27 T. pyogenes produces a number of extracellular or surface-exposed proteins involved in the infections caused by this bacterium. 38 Plo is a primary virulence factor with cytolytic activity related to transmembrane pore formation and considered as an important marker in the definitive diagnosis of T. pyogenes. 39,40 Similar to previous reports of bovine mastitis conducted in China and other countries, 6,7,11,29 plo was observed in all tested isolates, indicating it's a critical role in establishment of T. pyogenes infections.…”

Role of biofilms in antimicrobial resistance of the bacterial bovine respiratory disease complex

“…In a different study, silver nanoparticles (AgNP) targeting multidrug resistant T. pyogenes (dairy cattle clinical endometritis) decreased bacterial cell viability and biofilm formation by increasing oxidative stress ( 83 ). More recently, luteolin, a natural flavonoid found in plants, inhibited T. pyogenes biofilm-formation in vitro and was able to disperse pre-formed biofilms by decreasing TatD DNases binding to extracellular DNA ( 84 ). Additionally, luteolin significantly reduced clinical symptoms in a rat endometritis model caused by T. pyogenes ( 60 ).…”