Evaluation of antibacterial properties of human amniotic membrane in vitro

Amniotic membrane is the inner-most layer of the three fetal membranes. The membrane is consisted of three layers; epithelial layer، basal membrane، and connective tissue. Owing to expression of mRNA of elafin، HBD 1-3، and secretory leukocyte protease inhibitors، amniotic membrane has antimicrobial properties. The aim of the current study was to evaluate the in vitro antibacterial effect of human amniotic membrane on standard bacterial species of Salmonella enterica BAA-708، E. coli ATCC 25922، Pseudomonas aeruginosa ATCC 27853، Klebsiella pneumoniae ATCC 7881، and Enterococcus faecalis ATCC 29212. Fresh amniotic membranes were obtained from Organ Transplant Bank of Imam Khomeini Hospital in Tehran. The membranes were obtained from pregnant women who had negative tests for HIV، HBV، HCV، and syphilis after elective Cesarian section. The membranes were cut into 1. 5× 1. 5 cm pieces under sterile conditions. The membrane pieces were placed on Müller-Hinton agar medium containing the bacterial suspensions and then incubated at 37 °C for 24 hours. The antibacterial properties of amniotic membrane against Salmonella enterica and E. coli were demonstrated by development of the no growth halo، but for Pseudomonas aeruginosa only a very narrow halo was observed. The halo was not developed for Klebsiella pneumoniae and Enterococcus faecalis. Amniotic membrane showed antibacterial effects against a wide spectrum of bacteria. With regard to the increasing antibiotic resistance، use of amniotic membrane against pathogenic bacteria can be considered valuable.