Silver Nanoparticles Biosynthesis, Characterization and Their Antibacterial Activity against Multidrug-Resistant Bacteria in wasit Province, Iraq

Abstract

Out of 228 urine specimens collected from a patient with suspected UTIs, 40 (17.5%) Proteus mirabilis isolates were identified. The isolates were first identified as related to culture, microscopic examination and biochemical tests. Whole Proteus mirabilis isolates were examined for their resistance against 15 antibiotics belonging to different classes, the highest rates of resistance were against class Macrolide antibiotic (Rifampin and ‎Azthromicin) with (90%), followed by ‎Folate pathway antagonist class (Trimethoprim) (87.5%).‎ Resistance to class Penicillins (Ampicillin), Nitrofurans class ‎‎(Nitrofurantoin), Tetracyclines class (Tetracycline) was present in ‎‎(80%) isolates, and Cephalosporin class (Cephalexin) ‎‎(70%).‎While, the lowest resistance with Aminoglycoside (Amikacin) and ‎Carbapenem (Meropenem) (20%) resistance, followed by ‎Quinolone class Levofloxacin, Norfloxacin and Ciprofloxacin (35.5%)، ‎‎(32.5%)، (25%), respectively. Moreover, In the present study demonstrated that all Proteus ‎mirabilis isolates (100%) were multi drug resistance showing resistance to a minimum of three classes of the antibiotics tested. Using an extracellular technique, this bacteria's capacity to produce AgNPs may be discovered. AgNPs formed during biosynthesis were identified by Ultra violet spectrophotometer (UV-Vis) spectral analysis, which showed the greatest peak with a wavelength of 449 nanometers. In Energy dispersive x-ray(EDX) analysis, the atomic weight percentage of silver was (63.5%) Ag weight demonstrated that AgNPs are metallic and crystalline, Field emission scanning electron microscope (FE-SEM) reveals the morphology of silver nanoparticles, the particle size ranging between (40-100) nm in the scanned area, so the average particle size approximately around (66nm), the typical grain size of artificial nanoparticles ranged from 20 to 40 nm, according to Atomic force microscope(AFM) data for silver nanoparticle diameter. The current study has shown the great emergence of multidrug drug resistance in Proteus mirabilis isolate. Also, the results show that the antimicrobial synthesized by AgNPs was the most effective growth inhibitor against Gram-positive bacteria.