Anti Biofilm of Biosynthesized Silver Nanoparticles Mediated by Lactobacillus AcidophilusAgainst klebsiellapneumoniae

Abstract

The isolate of lactobacillus acidophiluswas obtained from the dairy products. These isolates were cultured on De man rogosa sharpe broth and agar for 24 h at 37°C.Based on the biochemical tests, these isolates identified as Lactobacillus acidophilus. And the fermentation test for carbohydrates distinguished the Lactobacillus acidophils, this isolate was diagnosed by biochemical tests and using the Vitek2 system as Lactobacillus acidophilus, the method of biosynthesis of nanoparticles is gaining an extremely significant field due to its economic and environmental advantages compared to the chemical and physical methods of synthesis.The goal of the current study is to use Lactobacillusacidophils to biosynthesize silver nanoparticles. Ag NPs were biosynthesized by adding silver nitrate (AgNO3) to the cell-free supernatant per Lactobacillus acidophilus at a concentration (5 mM) to be used as a precursor for the synthesis of Ag NPs. The color shift of AgNPs from yellow to reddish-brown was the first indication of biosynthesis. UV-visible spectrophotometry was used to characterize biosynthetic nanoparticles, and the maximum absorption peak of the nanoparticles (410 nm) was observed. The size and distribution of nanoparticles were determined using scanning electron microscopy (SEM), and the shape was circular, homogeneous, and the size varied from (30-100nm). The occurrence of Ag was investigated using Energy Dispersive(x-ray) Spectroscopy (EDS). Antibacterial activity of biosynthesized AgNPs against multidrug-resistant bacteria (MDR) of both gram-positive and gram-negative bacteria, as well as biofilm formation (Between September 2020 and March 2021, a total of (30)Klebsiella pneumoniae isolates were collected from clinical samples of urinary tract infection. The identification of Klebsiella pneumoniae isolates was established using morphological, cultural, and biochemical tests, and then confirmed using the Vitek-2 system. The numbers of obtained bacterial isolates according to the site of infection where (30) isolates urinary tract infection. regarding antibiotic susceptibility testing the present study demonstrate that all isolates (100%) were resistant to Ceftazidime, and Ceefpime (100%) respectively, whereas the lowest minocycline 26,67% due to misuse of antibiotics. The present study demonstrated the occurrence of some virulence factors such as capsule in all isolates (100%), biofilm formation was recorded in 10 isolates,.