Effects of Gamma Irradiation on Bacterial Microflora Associated with Human Amniotic Membrane

Abstract

Human amniotic membrane is considered a promising allograft material for the treatment of ocular surface reconstruction, burns, and other skin defects. In order to avoid the transmission of any diseases, grafts should be perfectly sterile. Twenty-five amniotic sacs were collected to determine the microbiological quality of human amniotic membrane, to analyze the radiation sensitivity pattern of the microorganism, and to detect the radiation decimal reduction dose (D10) values. All the samples were found to be contaminated, and the bioburden was ranged from 3.4 × 102 to 1.2 × 105 cfu/g. Initially, a total fifty bacterial isolates were characterized according to their cultural, morphological, and biochemical characteristics and then tested for the radiation sensitivity in an incremental series of radiation doses from 1 to 10 KGy. The results depict gradual decline in bioburden with incline of radiation doses. Staphylococcus spp. were the most frequently isolated bacterial contaminant in tissue samples (44%). The D10 values of the bacterial isolates were ranged from 0.6 to 1.27 KGy. Streptococcus spp. were found to be the highest radioresistant strain with the radiation sterilization dose (RSD) of 11.4 KGy for a bioburden level of 1000. To compare the differences, D10 values were also calculated by graphical evaluations of the data with two of the representative isolates of each bacterial species which showed no significant variations. Findings of this study indicate that lower radiation dose is quite satisfactory for the sterilization of amniotic membrane grafts. Therefore, these findings would be helpful to predict the efficacy of radiation doses for the processing of amniotic membrane for various purposes.

Biosurfactant Production Using Mutant Strains of Pseudomonas aeruginosa and Bacillus subtilis from Agro-industrial Wastes

“…41 Researchers have shown that UV, X-and γradiation could yield novel bioactive compounds in plants and animal models. [44][45][46] In the present study, after exposure of biosurfactant producers to ultraviolet light at different time intervals, various biochemical results indicated that the organisms were mostly not affected by short-term exposure (0-60 s) to UV light. Since all biochemical tests gave negative results between 600-900 s of isolates exposure to UV rays coupled with confirmatory result by culturing the remains of the isolates on nutrient agar where no growth was recorded, it can be concluded that 600-900 s exposure to UV rays destroyed the isolates completely while different growth and result patterns between 15 s to 300 s of UV rays indicated that the genetic makeup of the isolates were modified leading to various biochemical results recorded.…”

Effects of acellular equine amniotic allografts on the healing of experimentally induced full‐thickness distal limb wounds in horses

“…Amniotic scaffolds have been produced after extensive processing and decellularization techniques to address concerns regarding transmissible diseases in human medicine . Amniotic scaffolds can also be dehydrated, thereby allowing sterilization with gamma irradiation . Such process improves safety, facilitates storage at room temperature, and allows use in a point‐of‐care clinical setting.…”

“…[22][23][24][25] Amniotic scaffolds can also be dehydrated, thereby allowing sterilization with gamma irradiation. 22,26,27 Such process improves safety, facilitates storage at room temperature, and allows use in a point-of-care clinical setting.…”

Validation and assessment of an antibiotic-based, aseptic decontamination manufacturing protocol for therapeutic, vacuum-dried human amniotic membrane

“…The natural floral contamination of fresh AM obtained by ECS in the Queens’s Medical Centre, Nottingham University Hospitals NHS trust, was shown to be considerably lower than literature reported from normal vaginal deliveries 20,24,25 . 40% of the tested AM showed no signs of bioburden contamination, similar to results previously reported (39%) 20 .…”