Distribution of radiation resistances of microbiological contaminants of a cotton-based medical product

A distribution of radiation resistances of microorganisms has been compiled from the results of D10 determinations of isolates recovered from a cotton-based medical product. In all, 250 organisms were isolated from a total microbial population of around 21,000 organisms present on about 170 g of product. D10 values of the isolates fall within the range of 0.5 to 3.6 kGy. The findings indicate that organisms having a D10 value greater than 3.6 kGy occur amongst contaminants on this cotton product at a probability of less than 1 in 5000. The overall resistance of the population of organisms found in the present study is somewhat less than that of the ''Standard Distribution of Resistances'' used in '' AAMI dose setting methods''. (Author)