Radiation methods are widely used for disinfection and sterilization applications. Microorganisms demonstrate known, variable tolerance levels to inactivation with lower doses of ionizing and non-ionizing radiation based on multiple mechanisms of resistance in their structures and nucleic acid repair mechanisms. The radiation dose required to ensure microbial inactivation during sterilization is typically based on the understanding and routine monitoring of the natural population and resistance of microorganisms on products exposed to radiation sterilization processes. This report describes the isolation of Roseomonas mucosa in a device manufacturing environment that was detected during routine device bioburden and dose verification monitoring. Sources of Gram-negative bacteria in the environment were investigated. Non-sterile examination gloves used during manufacturing were found to be a persistent source of R. mucosa and other microbial contaminants. The source of contamination was determined to be from the glove manufacturing process. Maintenance and routine microbiological controls during glove manufacturing, including water systems, are required to reduce the risks of gloves being a source of unexpected microbiological contamination.
Keywords: microbial contamination; radiation; resistance; sterilization; water quality.