A PhD dissertation in the Department of Life Sciences at the College of Science, Al-Qadisiyah University, entitled “Antibacterial and Biofilm Activity of Cell-Free Filtrates of Ganoderma lucidum and Saccharomyces cerevisiae Against Multidrug-Resistant Clinical Isolates of Pseudomonas aeruginosa,” was conducted by researcher Noor Qahtan Ali and supervised by Professor Dr. Walaa Yass Lahmoud.

The dissertation aimed to evaluate the antibacterial and biofilm activity of cell-free filtrates extracted from Ganoderma lucidum and Saccharomyces cerevisiae against multidrug-resistant Pseudomonas aeruginosa, as well as to study their effect on gene expression of genes associated with bacterial resistance, virulence, and biofilm formation.

The results showed that the fungal and yeast filtrates possessed a clear ability to inhibit bacterial growth and reduce biofilm formation. Vitality was demonstrated, with fungal filtrate showing a marked advantage over yeast filtrate. The study also revealed that these filtrates exerted significant effects on regulating gene expression of genes associated with resistance and virulence, and contributed to weakening certain biological pathways responsible for bacterial communication and pathogenesis.