In vitro antibacterial activity of antibiotics and plant essential oils against <i>Escherichia coli</i> MTCC443 supported through the molecular docking and pharmacokinetics study

Abstract

Most of the Escherichia coli turned into serious pathogens or developed antibiotic resistance, mainly due to their ability to show different phenotypic traits. In order to overcome the resistance to these antibiotics, the use of essential oils (EOs) is of great significance against highly pathogenic microorganisms. This study has been made to compare the in vitro antibacterial activity and further validated the same through the molecular docking study of 13 antibiotics such as ciprofloxacin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, kanamycin, vancomycin, streptomycin, penicillin, nalidixic acid, trimethoprim, and polymyxin, and 10 EOs such as garlic, tulsi, neem, clove, thyme, peppermint, coriander, tea, lavender, and eucalyptus against the target protein (DNA gyrase) of E. coli MTCC443. E. coli Microbial Type Culture Collection 443 was found to be highly sensitive to ciprofloxacin (zone of inhibition [ZOI], 2.5 cm ±0.1) and chloramphenicol (ZOI, 1.8 cm ±0.1), whereas garlic oil (ZOI, 5.5 cm ±0.1) and coriander oil (ZOI, 4.4 cm ±0.1) were found comparatively most effective. Further, the in silico investigation observed the same; ciprofloxacin (binding affinity: -7.2 kcal/mol) and chloramphenicol (binding affinity: -6.6 kcal/mol). Penicillin (binding affinity: -4.2 kcal/mol) and polymyxin (binding affinity: -0.3 kcal/mol) were found to be least effective against the tested microbe, whereas vancomycin (binding affinity: +0.8 kcal/mol) had no effect on it. Garlic (binding affinity: -7.8 kcal/mol), coriander (binding affinity: -6.8 kcal/mol), peppermint (binding affinity: -6.2 kcal/mol), and neem (binding affinity: -6.2 kcal/mol) oil exhibited the potent antibacterial activity against E. coli MTCC443, whereas thyme (binding affinity: -6.1 kcal/mol), tea tree (binding affinity: -4.9 kcal/mol), and tulsi (binding affinity: -3.8 kcal/mol) oil were observed moderately effective. Eucalyptus (binding affinity: -2.9 kcal/mol) and lavender (binding affinity: -2.8 kcal/mol) oil were found to be the least effective among all the oils tested. The pharmacokinetics and networking were performed to the pharmacology of the potential compounds.