School of Life Sciences, B.S. Abdur Rahman Crescent Institute of Science and Technology, Chennai, Tamil Nadu, 600048, India.
Department of Biotechnology, Indian Academy Degree College, Bangalore, Karnataka, 560043, India.
Curr Microbiol. 2021 Nov;78(11):3843-3852. doi: 10.1007/s00284-021-02655-x. Epub 2021 Sep 23.
Primarily synthesized for chelating metal ions from the surrounding media, the pyomelanin plays an important role in bacterial virulence where it is needed for infection and biofilm formation as well as protection from host immune response. In this study, two out of three phenolic acids, gallic acid, and propyl gallate induced pyomelanin in two clinical isolates of Pseudomonas aeruginosa and inhibited biofilm formation. Ascorbic acid treatment reversed the gallic acid and propyl gallate mediated pyomelanin synthesis without reversing the inhibition of the biofilm formation. mRNA expression study revealed the upregulation of homogentisic acid oxidase enzyme by ascorbic acid treatment, possibly contributing towards the inhibition of pyomelanin synthesis. Tannic acid did not show any antibacterial or pyomelanin-induction activities. The synergistic effect of gallates and ascorbic acid in the inhibition of biofilm formation and associated pyomelanin synthesis was evidenced which needs further studies to establish their antibacterial efficacies, especially against the clinical isolates of Pseudomonas sp.
主要用于从周围介质中螯合金属离子，原黑质在细菌毒力中起着重要作用，它需要用于感染和生物膜形成以及保护免受宿主免疫反应。在这项研究中，三种酚酸中的两种，没食子酸和丙酸没食子酯，诱导了两种临床分离的铜绿假单胞菌的原黑质，并抑制了生物膜的形成。抗坏血酸处理逆转了没食子酸和丙酸没食子酯介导的原黑质合成，而没有逆转生物膜形成的抑制作用。mRNA 表达研究表明，抗坏血酸处理上调了对羟基苯丙酮酸氧化酶酶，可能有助于抑制原黑质的合成。单宁酸没有显示任何抗菌或原黑质诱导活性。没食子酸和抗坏血酸在抑制生物膜形成和相关原黑质合成方面的协同作用得到了证实，需要进一步的研究来确定它们的抗菌功效，特别是针对铜绿假单胞菌的临床分离株。
