<i>Ocimum sanctum</i> as a Source of Quorum Sensing Inhibitors to Combat Antibiotic Resistance of Human and Aquaculture Pathogens
Sybiya Vasantha Packiavathy Issac Abraham,
Veera Ravi Arumugam,
Nancy Immaculate Mary,
Jeba Sweetly Dharmadhas,
Rajamanikandan Sundararaj,
Arul Ananth Devanesan,
Ramachandran Rajamanickam,
Raja Veerapandian,
John Paul John Bosco,
Jeyapragash Danaraj
Affiliations
Sybiya Vasantha Packiavathy Issac Abraham
Division of Biotechnology, Karunya Institute of Technology and Sciences, Coimbatore 641 114, Tamil Nadu, India
Veera Ravi Arumugam
Department of Biotechnology, Alagappa University, Karaikudi 630 003, Tamil Nadu, India
Nancy Immaculate Mary
Department of Biotechnology, Alagappa University, Karaikudi 630 003, Tamil Nadu, India
Jeba Sweetly Dharmadhas
Department of Biochemistry and Biotechnology, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore 641 043, Tamil Nadu, India
Rajamanikandan Sundararaj
Centre for Drug Discovery, Karpagam Academy of Higher Education, Coimbatore 641 021, Tamil Nadu, India
Arul Ananth Devanesan
Department of Biotechnology, The American College, Satellite Campus, Madurai 625 503, Tamil Nadu, India
Ramachandran Rajamanickam
Department of Biotechnology, Srimad Andavan Arts and Science College (Autonomous), Tiruchirappalli 620 005, Tamil Nadu, India
Raja Veerapandian
Department of Molecular and Translational Medicine, Center of Emphasis in Infectious Diseases, Texas Tech University Health Sciences Center, El Paso, TX 79905, USA
John Paul John Bosco
Division of Electronics and Communication Engineering, Karunya Institute of Technology and Sciences, Coimbatore 641 114, Tamil Nadu, India
Jeyapragash Danaraj
Centre for Ocean Research, Sathyabama Research Park, Sathyabama Institute of Science and Technology, Chennai 600 119, Tamil Nadu, India
Biofilms play a decisive role in the infectious process and the development of antibiotic resistance. The establishment of bacterial biofilms is regulated by a signal-mediated cell–cell communication process called “quorum sensing” (QS). The identification of quorum sensing inhibitors (QSI) to mitigate the QS process may facilitate the development of novel treatment strategies for biofilm-based infections. In this study, the traditional medicinal plant Ocimum sanctum was screened for QS inhibitory potential. Sub-MICs of the extract significantly affected the secretion of EPS in Gram-negative human pathogens such as Escherichia coli, Pseudomonas aeruginosa PAO1, Proteus mirabilis, and Serratia marcescens, as well as aquaculture pathogens Vibrio harveyi, V. parahaemolyticus, and V. vulnificus, which render the bacteria more sensitive, leading to a loss of bacterial biomass from the substratum. The observed inhibitory activity of the O. sanctum extract might be attributed to the presence of eugenol, as evidenced through ultraviolet (UV)-visible, gas chromatography-mass spectroscopy (GC–MS), Fourier transformer infrared (FTIR) spectroscopy analyses, and computational studies. Additionally, the QSI potential of eugenol was corroborated through in vitro studies using the marker strain Chromobacterium violaceum.
