Isolation and characterization of bacteria from human amniotic membrane and determination of radiation sensitivity of isolates

Abstract

The possibility of infectious diseases transmission through tissue allograft is very crucial in good tissue banking practice. The present study was therefore aimed to elucidate the antibiotic and radiation sensitivity pattern of amniotic membrane (AM) associated bacteria for choosing a suitable radiation dose to reduce the bioburden level effectively. Based on biochemical characteristics, thirty bacterial isolates were presumptively identified as Klebsiella spp., Staphylococcus spp., E. coli, Bacillus spp., Moraxella spp. and Citrobacter spp. They showed high resistance to Penicillin (100%), Ampicillin (90%), Vancomycin (87%) and Streptomycin (80%). Most of the isolates were sensitive to Ciprofloxacin, Imipenem and Polymixin B. Two strain of gram-positive bacteria Staphylococcus spp. (AMI01 and AMI11) and one strain of Bacillus spp. (ASI08) were found to survive at 7 kGy gamma irradiation. The D₁₀ value range of gram-positive isolates was 0.89 to 0.94 whereas for gram-negative bacteria the range was 0.63 kGy to 0.90 kGy.  Bacterial load was reduced in decimal reduction rate with the increment of radiation dose and 8.0 kGy gamma irradiation dose was found enough to eradicate the bioburden associated with the amnion samples.