Impact of Solidago virgaurea Extract on Biofilm Formation for ESBL-Pseudomonas aeruginosa: An In Vitro Model Study

The increasing disparity between antimicrobial resistance (AMR) and the development of new antimicrobials continues to pose a significant global health concern. However, plant extracts have shown promise in combating this issue either through their inherent antimicrobial activity or by serving as potential reservoirs of effective antimicrobial compounds. These compounds have the ability to target pathogenic biofilms and inhibit the production of extended-spectrum beta -lactamases (ESBLs). However, there is limited research available on the antibacterial properties of goldenrod extract. Thus, the objective of this study was to investigate the impact of S. virgaurea (SV) extract on the viability and ability to form biofilms of ESBL-Pseudomonas aeruginosa (P. aeruginosa). A cross-sectional study was conducted from August 2022 to March 2023. The broth microdilution method was employed to determine the minimum inhibitory concentration (MIC) of the (SV) extract. Subsequently, the minimum bactericidal concentration (MBC) was determined based on the MIC values obtained. The antibiotic susceptibility of bacteria was evaluated using the Kirby disk diffusion assay and an Antimicrobial Susceptibility Testing (AST) card in conjunction with the Vitek-2 compact system. Biofilm formation was evaluated using Congo red and a 96-well Elisa plate, while the presence of extended-spectrum beta-lactamases (ESBLs) was estimated by measuring the reduction of nitrocefin at a wavelength of 390 nm. In addition, treatment of biofilm and ESBL activity with SV extract using 96-well Elisa plate and nitrocefin hydrolyzing, respectively. The resistance rates of P. aeruginosa isolates to the tested antibiotics were as follows: Levofloxacin 33%, Ciprofloxacin 40%, Amikacin 49%, Meropenem 50%, Cefepime 70%, Ceftazidime 75%, Cefotaxime 85%, Piperacillin-Tazobactam 90%, Amoxiclav 97%, Ampicillin 99%, Ceftriaxone 100%. The prevalence of MDR-P. aeruginosa, XDR-P. aeruginosa, PDR-P. aeruginosa and non-MDR-PA were 40% (n = 40), 7% (n = 7), 3% (n = 3) and 50% (n = 50), respectively. From the GC-MS results, it was observed that the presence of Octadecane, Clioquinol, Glycerol tricaprylate, hexadecanoic acid, cis-13-octadecenoic acid, oleic acid and Propanamide were the major components in the Solidago extract. In the determination of plant crude extracts, the values ranged between 0.25 and 64 mg/mL against bacteria. The resulting activity of the extract showed a significant statistical relationship at a p-value <= 0.01 against ESBL production and biofilm formation in P. aeruginosa. The S. virgaurea extract exhibited effectiveness in inhibiting biofilm formation and combating P. aeruginosa strains that produce extended-spectrum beta-lactamases (ESBLs).

Automated summary

The increasing disparity between antimicrobial resistance and the development of new antimicrobials continues to pose a significant global health concern. This study found that goldenrod extract has the ability to inhibit the production of extended-spectrum beta-lactamases (ESBLs) and biofilm formation in ESBL-Pseudomonas aeruginosa.