For safety, designated Select Agents in tissues must be inactivated and viability tested before the tissue undergoes further processing and analysis. In response to the shipping of samples of "inactivated" Bacillus anthracis that inadvertently contained live spores to nonregulated entities and partners worldwide, the Federal Register now mandates in-house validation of inactivation procedures and standardization of viability testing to detect live organisms in samples containing Select Agents that have undergone an inactivation process. We tested and validated formaldehyde and glutaraldehyde inactivation procedures for animal tissues infected with virulent B. anthracis, Burkholderia pseudomallei, Francisella tularensis, and Yersinia pestis. We confirmed that our fixation procedures for tissues containing these Tier 1 Select Agents resulted in complete inactivation and that our validated viability testing methods do not interfere with detection of live organisms. Institutions may use this work as a guide to develop and conduct their own testing to comply with the policy.
Keywords: Bacillus anthracis; Burkholderia mallei; Burkholderia pseudomallei; Francisella tularensis; Select Agents; Tier 1; Yersinia pestis; bacteria; formaldehyde; formalin; glutaraldehyde; guinea pigs; inactivation; liver; lung; neutralization methods; outer ear pinna; paraformaldehyde; rabbits; skin; spleen; spores; sterility; viability testing.