The Food and Drug Administration has become aware of several instances where supposedly sterile medical surgical products made of Chinese cotton have been found to contain viable Pyronema domesticum. The aim of this research was to determine the gamma and electron beam radiation resistance values for the two dormant phases (ascospores and sclerotia) of P. domesticum. The resistance values were obtained by developing a standardized system to cultivate, purify, and harvest biological indicators containing sclerotia or ascospores. Ascospores were more resistant to radiation than sclerotia. The D 10 values for sclerotia were 0.79 and 1.09 kGy for strains 32030 and 14881, respectively. The resistance value for wild type ascospores was 2.83 kGy. The current standard for assuring radiation sterilization of medical devices is ISO 11137. This standard was developed to address the propensity for highly radiation-resistant organisms such as P. domesticum. Prior to the standard, biological indicators such as Bacillus pumilus, having a nominal D 10 value or 1.7 kGy, were used to determine the sterility of many medical devices. Journal of Industrial Microbiology & Biotechnology (2002) 29, 51–54 doi:10.1038/sj.jim.7000267
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received 09 October 2001/ Accepted in revised form 08 April 2002
Rights and permissions
About this article
Cite this article
Richter, S., Barnard, J. The radiation resistance of ascospores and sclerotia of Pyronema domesticum . J Ind Microbiol Biotech 29, 51–54 (2002). https://doi.org/10.1038/sj.jim.7000267
Issue Date:
DOI: https://doi.org/10.1038/sj.jim.7000267