Indian medicinal plant extracts to control multidrug-resistant S. aureus, including in biofilms

The objective of this study is to evaluate the in vitro antibacterial effectiveness of select Indian medicinal plants against multidrug-resistant (MDR) and biofilm-forming Staphylococcus. Twenty Indian medicinal plants used traditionally were preselected for testing against 17 different clinical strains (originating from animal or hospital patients), resistant to five classes of antibiotics, and one biofilm-forming Staphylococcus. The minimum inhibitory concentration (MIC50) and biofilm inhibitory concentration (BIC50) were determined. Plants with anti-staphylococcal activity not reported before include Cinnamomum glaucescens, Smilax zeylanica, Syzygium praecox, Trema orientalis, Bischofia javanica, Elaeocarpus serratus, Acacia pennata, Holigarna caustica, Murraya paniculata, and Ptelygota alata. They can be used to control the formation of S. aureus biofilms, or to discover active molecules that may lead to novel drugs. In addition to the aforementioned plants, Beilschmiedia roxburghiana and Mikania micrantha also deserve further study regarding their mechanism of action, as they inhibit the growth of S. aureus resistant to all five groups of antibiotics tested. The active compounds from the aforementioned plants have potential in the fight against multidrug-resistant Staphylococcus infections. (C) 2019 SAAB. Published by Elsevier B.V. All rights reserved.