[Determination of Antibacterial Activity of Taraxacum officinale Extracts Against Bacterial Isolates Obtained from Clinical Samples and Comparison of Their Antioxidant Properties].

The rise in antibiotic-resistant microorganisms poses challenges in treating infectious diseases. It is known that Taraxacum officinale (dandelion) extracts have antimicrobial effects. This study aimed to investigate the antibacterial activities of different parts of T.officinale extracted through the Soxhlet device, against bacteria with various resistance patterns that cause hospital-acquired infections. The antibacterial effects of ethanolic and methanolic extracts were tested against Staphylococcus aureus, Enterococcus spp. (Enterococcus faecalis and Enterococcus faecium), Escherichia coli and Pseudomonas aeruginosa isolates obtained from clinical samples using disc and agar well diffusion methods. Besides, the total phenolic (TPC) and flavonoid contents (TFC) of the extracts, as well as their total antioxidant capacities (TAC), were evaluated in relation to their antibacterial activities. Mean inhibition zone diameters produced by extracts ranged between 6.0-8.0 mm in the disc diffusion method and 8.0-20.6 mm in the agar well diffusion method. Antibacterial activity was more pronounced particularly against S.aureus isolates. However, inhibition zone diameters against Enterococcus spp. isolates were found to be larger compared to those against other bacteria. Ethanolic and methanolic flower extracts had higher antibacterial activity on the isolates compared to leaf and root extracts. However, the TPC, TFC, and TAC values of ethanolic leaf extracts were higher than those of the other extracts, with values of 78.09 ± 1.13 mg GAE/g extract DW, 197.20 ± 6.22 mg QE/g extract DW, and 2.65 ± 0.03 µg AAE/mL extract, respectively.This study presents preliminary data on the antibacterial potential of herbal extracts against infections caused by resistant isolates.