Evaluation of the inhibitory effect of Ganoderma lucidumextract and TiO۲ nanoparticle against biofilm-producing bacteriaisolated from clinical samples

Background and Aim : The emergence of antimicrobial-resistant pathogens, especially in healthcare units, lead to treatment failure. The formation of biofilms also is the main contributing factorto antibiotic resistance. So, the need for new antibacterial drugs is urgent. Ganoderma lucidum isa well-known mushroom that has various therapeutic properties like antimicrobial activity. TiO۲nanoparticles possess desirable inhibitory and bactericidal effectsMethods : In the present study, we evaluated the efficiency of TiO۲ and Ganoderma extractagainst biofilms-producing Pseudomonas aeruginosa and Staphylococcus aureus. Biofilmformation was detected by the microtiter plate method. For this purpose, first, we determined theminimum inhibitory concentration (MIC) of tested compounds by the microdilution broth method.Then, MIC, sub-MIC, ۲MIC, and ۴ MIC concentrations effects of TiO۲ and Ganoderma extractwere assessed against strong biofilms-producing isolates. Synergistic interaction between TiO۲and Ganoderma extract was detected using checkerboard assay. Data were analyzed using thegraph pad through ANOVA and t-test.Results : According to our results, bacterial sensitivity to TiO۲, and Ganoderma extract dependedon the bacterial species. The average MICs of TiO۲, Ganoderma extract, and combination of TiO۲and Ganoderma extract against P. aeruginosa and S. aureus were ۳۸۹.۹, ۱۳۸.۰۴, ۸۶.۸, ۲۱۵.۰۲, ۷۸.۳,and ۱۲۱.۰۹ μg/mL, respectively. The ۲ MIC concentration of TiO۲ and Ganoderma reduced thebiofilm formation rate of S. aureus but test compounds had no significant effect on the decrease ofP. aeruginosa biofilm.Conclusion : Taken together, these findings revealed that nanoparticles and natural substancesmight represent the potential to be used for the development of promising antibacterial therapies,especially against gram-positive species in the coming years.

کلیدواژه ها:

Ganoderma lucidum extract ، TiO۲ nanoparticle ، antibiofilm