Evaluation of Catechin Synergistic and Antibacterial Efficacy on Biofilm Formation and acrA Gene Expression of Uropathogenic E. coli Clinical Isolates

Creative Commons License

Jubair N., Mogana R., FATIMA A., Mahdi Y. K., Abdullah N. H.

ANTIBIOTICS-BASEL, vol.11, no.9, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 11 Issue: 9
  • Publication Date: 2022
  • Doi Number: 10.3390/antibiotics11091223
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, CAB Abstracts, Chemical Abstracts Core, EMBASE, Veterinary Science Database, Directory of Open Access Journals
  • Keywords: Canarium patentinervium Miq, multidrug resistance, antibiofilm activity, AcrAB-TolC efflux pump, molecular docking, Autodock Vina, ANTIMICROBIAL ACTIVITY, EXTRACTS, ASSAY
  • Bezmialem Vakıf University Affiliated: Yes


Uropathogenic Escherichia coli has a propensity to build biofilms to resist host defense and antimicrobials. Recurrent urinary tract infection (UTI) caused by multidrug-resistant, biofilm-forming E. coli is a significant public health problem. Consequently, searching for alternative medications has become essential. This study was undertaken to investigate the antibacterial, synergistic, and antibiofilm activities of catechin isolated from Canarium patentinervium Miq. against three E. coli ATCC reference strains (ATCC 25922, ATCC 8739, and ATCC 43895) and fifteen clinical isolates collected from UTI patients in Baghdad, Iraq. In addition, the expression of the biofilm-related gene, acrA, was evaluated with and without catechin treatment. Molecular docking was performed to evaluate the binding mode between catechin and the target protein using Autodock Vina 1.2.0 software. Catechin demonstrated significant bactericidal activity with a minimum inhibitory concentration (MIC) range of 1-2 mg/mL and a minimum bactericidal concentration (MBC) range of 2-4 mg/mL and strong synergy when combined with tetracycline at the MBC value. In addition, catechin substantially reduced E. coli biofilm by downregulating the acrA gene with a reduction percent >= 60%. In silico analysis revealed that catechin bound with high affinity ( increment G = -8.2 kcal/mol) to AcrB protein (PDB-ID: 5ENT), one of the key AcrAB-TolC efflux pump proteins suggesting that catechin might inhibit the acrA gene indirectly by docking at the active site of AcrB protein.