Evaluation of Chitosan Nanoparticle Antimicrobial Effect on Isolated Listeria monocytogenes Bacteria from Pregnant Women and L. monocytogenes ATCC 7644

is a gram positive, facultative intracellular bacteria and it is a causative agent of . Abortion is one the most important side effect of . Nano chitosan is widely used as nanomaterials considered due to its characteristics such as bactericidal and nontoxicity activity. The aim of this study was isolation of bacteria from pregnant women vaginal samples and evaluation of chitosan nanoparticles effects against them. Overall, 100 vaginal specimens were collected from pregnant women with and without a history of abortion referred to Tehran's Hospitals from Sep 2019 to Jul 2020 with questionnaires. Then, using biochemical methods, bacteria were isolated and identified. Isolated strains were confirmed using PCR and evaluation of gene, which is the main gene for identification of this bacterium. The effect of chitosan nanoparticles was evaluated in comparison with the antibiotics used based guideline on isolated bacteria by well diffusion method. and were determined for nanoparticle at the end. Five strains of that were confirmed by PCR method. Moreover, a statistically significant relationship was observed between the isolated strains and the samples taken from women with a history of abortion. MIC and MBC for ATCC 7644 were 156.25 and 312.5 μg/ml and for 5 isolated strains were 78.12 and 158.25 μg/ml, respectively. could be a causative agent of abortion in pregnant women. Concerning the results, Nano chitosan has acceptable antibacterial activity against .