Thymoquinone’ potent impairment of multidrug-resistant Staphylococcus aureus NorA efflux pump activity

• Published in: Scientific reports Vol. 14; no. 1; pp. 16483 - 11
• Main Authors: Ahmad, Adel Attia M., Abdelgalil, Sara Y., Khamis, Tarek, Abdelwahab, Ashraf M. O., Atwa, Dina Nader, Elmowalid, Gamal A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17-07-2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/154; 631/1647; 631/326; 631/337; 692/308; Anti-Bacterial Agents - pharmacology; Antimicrobial agents; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Benzoquinones - metabolism; Benzoquinones - pharmacology; Ciprofloxacin; Ciprofloxacin - pharmacology; Doxycillin; Doxycycline; Doxycycline - pharmacology; Drug Resistance, Multiple, Bacterial - drug effects; Drug Resistance, Multiple, Bacterial - genetics; Efflux pump inhibitor; Essential oils; Ethidium bromide; Gene expression; Gene Expression Regulation, Bacterial - drug effects; Humanities and Social Sciences; Microbial Sensitivity Tests; Molecular Docking Simulation; multidisciplinary; Multidrug resistance; Multidrug Resistance-Associated Proteins - genetics; Multidrug Resistance-Associated Proteins - metabolism; Multidrug resistant organisms; NorA protein; Pharmacokinetics; Regression analysis; Science; Science (multidisciplinary); Staphylococcus aureus; Staphylococcus aureus - drug effects; Thymoquinone; Verapamil; Doxycillin; Efflux pump inhibitor; Ciprofloxacin; Thymoquinone; Staphylococcus aureus
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-65991-5

The drug efflux pump is a crucial mechanism implicated in resistance to multiple antimicrobials. Thymoquinone (TQ) has evidently demonstrated multiple activities, antibacterial being the most effective. Knowledge about TQ activity against multidrug-resistant
Staphylococcus aureus
is very scarce. Therefore, the present study was conducted to investigate TQ resistance modulation in ciprofloxacin (CIP) and doxycycline (DO) multidrug-resistant
S. aureus
. Forty-seven samples were collected from different sources, and
S. aureus
was isolated and identified. Then,
S. aureus
resistance profiles to antimicrobials,
N. sativa
essential oil, and TQ; the correlation between TQ-MIC readings and disc diffusion; cartwheel and ethidium bromide (EtBr) accumulation assays; and
norA
gene expression were all described within silico molecular docking for TQ interactions with norA efflux pump protein. TQ-MICs ranged from 5–320 µg/ml. TQ down-regulated
norA
gene expression, resulting in a drop in efflux pump activity of 77.5–90.6% in the examined strains, comparable to that observed with verapamil. Exposure of
S. aureus
strains to CIP and DO raises the initial basal efflux pumping expression to 34.2 and 22.9 times, respectively. This induced efflux pumping overexpression was substantially reduced by 97.7% when TQ was combined with CIP or DO. There was a significant reduction of MICs of CIP and DO MICs by 2–15 and 2–4 folds, respectively, after treatment with 0.5XMIC-TQ in resistance modulation assays. These results refer to TQ ligand inhibitory interactions with NorA protein in molecular docking. Interpretations of inhibition zone diameters (IZDs) of disc diffusion and TQ-MICs exhibit independence of MICs from IZDs, as indicated by invalid linear regression analysis. TQ significantly reduced efflux pumping
S. aureus
induced by CIP and DO, but further investigations are needed to improve TQ-pharmacokinetics to restore CIP and DO activity and suppress fluoroquinolone and doxycycline-resistant
S. aureus
selection in clinical and animal settings.