Comparison of Different Concentrations of Antibiotics with Nanoparticles Synthesized by Biological Method on Pseudomonas aeruginosa Isolated from The Surface

Background: The widespread and indiscriminate use of antibiotics, disinfectants, and antiseptics in medical centers has led to the emergence of resistance in Pseudomonas aeruginosa, a major cause of hospital infections. Objectives: This study aims to compare the effects of antibiotics—cotrimoxazole, cephalexin, cefotaxime, cefazolin, gentamicin, imipenem, ampicillin, and ceftazidime—with silver nanoparticles synthesized in medicinal plant extract against Pseudomonas aeruginosa bacteria. Methods: Ten antibiotic-resistant strains of Pseudomonas aeruginosa were isolated from surfaces at the maternity hospital of Amir al-Mominin Hospital in Zabul city. In this study, nanoparticles were synthesized using an aqueous extract of the medicinal plant Capparis. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of the synthesized nanoparticles and antibiotics were determined by the microdilution method. Results: The minimum inhibitory concentrations for the antibiotics ceftriaxone, cephalexin, cotrimoxazole, gentamicin, cefotaxime, imipenem, ceftazidime, ampicillin, and cefazolin were 128, 64, 32, 16, 4, 64, 64, 8, and 64 µg/mL, respectively. The minimum inhibitory concentration for the synthesized silver nanoparticles was 1024 μg/mL, with inhibition observed in four strains at this concentration. Conclusions: This study demonstrated good antimicrobial effects of synthesized silver nanoparticles on Pseudomonas aeruginosa. Therefore, silver nanoparticles may be recommended as a potent antimicrobial agent for disinfecting hospital surfaces.