Destruction of biological weapons by gamma radiation
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Date
2019-06
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Publisher
Turkish Atomic Energy Authority
Abstract
Mikroorganizmaların radyasyona bağlı inaktivasyon prosesinin mekanistik özellikleri analiz edildi; bir reaksiyon mekanizması önerildi ve bu mekanizmaya uygun olarak mikrobiyal silahların etkisiz hale getirilmesi ve sterilizasyonu için doza bağlı bir inaktivasyon kinetiği çıkarıldı. Kinetik model, Bacillus anthracis 34F2 sterne’in canlı kalan deneysel konsantrasyon değerleri kullanılarak doğrulandı. Yağsız süt ile karıştırıldıktan sonra kurutulmuş Bacillus anthracis 34F2 sterne örnekleri, 25 °C'de 0-31 kGy gama radyasyon dozlarında ışınlandı ve daha sonra tamponlanmış peptonlu suyla yıkanarak alındı ve petri kaplarındaki triptik soy agar üzerine dökme yöntemiyle kaplanarak ekildi. Petri kapları daha sonra 37 °C'de 18-24 saat inkübe edildi ve mikroorganizma kolonileri sayıldı. Geliştirilen kinetik modelde deneysel canlı kalan koloni verileri kullanılarak, bir mikroorganizma kolonisinde başlangıçtaki hücre sayısı (no: 3.17 hücre / CFU), radyasyon hassasiyeti (G: 0.45 kGy-1), eşik dozu (De : 2.59 kGy), ondalık azalma dozu (D10: 5.18 kGy), sterilite güvence dozu (DSAL: 31.05 kGy) ve minimum sterilizasyon dozu (DMRD: 62.10 kGy) hesaplandı. Bu parametreler birbirleriyle ve önerilen reaksiyon mekanizmasıyla ilişkilendirildi, değerleri başka çalışmalarda rapor edilmiş değerlerle karşılaştırıldı. Model eşitliğinde kinetik parametrelerinin sayısal değerleri kullanılarak Bacillus anthracis 34F2 sterne’in doza bağımlı inaktivasyon kinetiği simüle edildi ve deneysel verilerle karşılaştırıldı. İnaktivasyon doğrusunun korelasyon katsayısı (r: 0.9709), kinetik denklemlerin ve karşılık gelen mekanizmanın Bacillus anthracis 34F2 sterne’in doza bağlı inaktivasyon proseslerini tarif etmek için uygun olduğunu (P <0.001) gösterdi. Önerilen model ve model parametrelerinin biyolojik silahların radyasyonla sterilizasyonu için proses etkinliği kontrolü ve doz ayarlamada kullanılabileceği sonucuna varıldı.
The mechanistic aspects of the radiation induced inactivation process of microorganisms were analyzed; a reaction mechanism was proposed, and accordingly a dose-dependent inactivation kinetics was developed for the inactivation and sterilization of microbial weapons. The kinetic model was validated using experimental survival values of Bacillus anthracis 34F2 sterne. Dried samples of Bacillus anthracis 34F2 sterne spores mixed with non-fat milk were irradiated at 0-31 kGy gamma radiation doses at 25 oC and then eluted with buffered peptone water, and plated on tryptic soy agar by the pour technique in petri dishes. The plates were then incubated at 37 oC for 18-24 h and microorganism colonies were counted. By using the experimental survival data in the developed kinetic model, the inactivation parameters including initial cell number in a microorganism colony (no: 3.17 cells/CFU), radiation sensitivity (G: 0.45 kGy-1), threshold dose (De: 2.59 kGy), decimal reduction dose (D10: 5.18 kGy), sterility assurance dose (DSAL: 31.05 kGy), and minimum sterilization dose (DMRD: 62.10 kGy) were evaluated. These parameters were correlated with each other and the proposed mechanism and their values were compared with literature. By using the numerical values of kinetic parameters in the model equation, the dose dependent inactivation kinetics of Bacillus anthracis 34F2 sterne was simulated and compared with experimental data. Correlation coefficient (r: 0.9709) of the inactivation line indicated that the kinetic equations and corresponding mechanism were acceptable (p<0.01) for describing the dose dependent inactivation processes of Bacillus anthracis 34F2 sterne. It is concluded that developed model and model parameters can be used for the process efficacy control and dose setting for radiation sterilization of biological weapons.
The mechanistic aspects of the radiation induced inactivation process of microorganisms were analyzed; a reaction mechanism was proposed, and accordingly a dose-dependent inactivation kinetics was developed for the inactivation and sterilization of microbial weapons. The kinetic model was validated using experimental survival values of Bacillus anthracis 34F2 sterne. Dried samples of Bacillus anthracis 34F2 sterne spores mixed with non-fat milk were irradiated at 0-31 kGy gamma radiation doses at 25 oC and then eluted with buffered peptone water, and plated on tryptic soy agar by the pour technique in petri dishes. The plates were then incubated at 37 oC for 18-24 h and microorganism colonies were counted. By using the experimental survival data in the developed kinetic model, the inactivation parameters including initial cell number in a microorganism colony (no: 3.17 cells/CFU), radiation sensitivity (G: 0.45 kGy-1), threshold dose (De: 2.59 kGy), decimal reduction dose (D10: 5.18 kGy), sterility assurance dose (DSAL: 31.05 kGy), and minimum sterilization dose (DMRD: 62.10 kGy) were evaluated. These parameters were correlated with each other and the proposed mechanism and their values were compared with literature. By using the numerical values of kinetic parameters in the model equation, the dose dependent inactivation kinetics of Bacillus anthracis 34F2 sterne was simulated and compared with experimental data. Correlation coefficient (r: 0.9709) of the inactivation line indicated that the kinetic equations and corresponding mechanism were acceptable (p<0.01) for describing the dose dependent inactivation processes of Bacillus anthracis 34F2 sterne. It is concluded that developed model and model parameters can be used for the process efficacy control and dose setting for radiation sterilization of biological weapons.
Description
Keywords
Anthrax, Şarbon, Bilogical weapon, Biyolojik silah, Radiation sterilization, Radyasyon sterilizasyonu, Inactivation kinetics, Inaktivasyon kinetiği, Decimal reduction dose, Ondalık azaltma dozu, Sterility assurance level, Sterilite güvence seviyesi, Minimum sterilization dose, Minimum sterilizasyon dozu, Bacillus anthracis 34F2 sterne
Citation
Tükenmez, İ. ve Kırcı, Ö. B. (2019). Destruction of biological weapons by gamma radiation. Turkish Journal of Nuclear Sciences, 31(1), 30-41.