Molecular and Anti Biofilm Study of Biosynthesized Silver Nanoparticles Mediated by Lactobacillusplantarum against Klebsiellapneumoniae Isolated from Urinary Tract Infaction

Abstract

The isolate of Lactobacillusplantarum. was 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 plantarum. and the fermentation test for carbohydrates distinguished the Lactobacillus.plantarum., this isolate was diagnosed by biochemicaltests  and using Vitek2 system as Lactobacillus plantarum, 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 Lactobacillus Plantarum to biosynthesize silver nanoparticles. Ag NPs were biosynthesized by adding silver nitrate (AgNO3) to the cell-free supernatant per Lactobacillus Plantarum 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 15 Klebsiella pneumonia isolates were collected from clinical samples of urinary tract infection. The identification of Klebsiella pneumonia 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 site of infection wer (15)   isolates urinary tract infection. regarding antibiotic susceptibility testing the present study demonstrate that all isolates (100%) were resistance to Ceftazidime, and Ceefpime (100%) respectively  , whereas the lowest minocycline 26,67% du 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,. The molecular detection of some virulence genes (wbbm, mrkD and wzm) was done by conventional PCR technique. It was found that high occurrence.

The goal of the current study was to investigate the formation of biofilm to Klebsiella pneumonia and the relationship between biofilm formation and the presence of (wbbm, mrkD and wzm) genes of K. pneumonia isolates respectively .