The AOAC Stakeholders Panel on Agent Detection Assays (SPADA) recently approved--by consensus--environmental factors, criteria for panel selection, inclusivity and exclusivity panels, and method performance requirements for PCR-based assays for the detection of Yersinia pestis and Francisella tularensis. Testing plans and method performance requirements are adapted from the requirements for PCR-based assays for detection of Bacillus anthracis spores, previously approved by SPADA in April 2008.

The recommendations for environmental factors, including list of powders and chemicals (sources for collection, characterization methods, concentrations to be applied), pooling scheme, and soil characterization and concentrations, were approved by SPADA on January 22, 2009, with amendments. SPADA recommended including an additional powder to the list.

The criteria for F. tularensis inclusivity panel selection, as well as the recommended strains for inclusivity and near-neighbor exclusivity panels, were approved by SPADA. Inclusivity panel selection is largely based on genetic diversity.

Criteria for Y. pestis panel selection were also approved by SPADA--with the removal of the virulence status. The criteria include genetic relationship, such as DNA sequences, plasmid variations, and Achtman genotypes. SPADA also approved the inclusivity and near-neighbor exclusivity panels. The approved inclusivity panel includes the addition of two U.S. strains and an additional strain recommended by SPADA. The exclusivity panel includes source, sequence, and availability information.

In addition, SPADA approved recommendations for method performance requirements for Y. pestis and F. tularensis PCR-based assays. Method performance requirements for Y. pestis and F. tularensis include performance parameters, parameter definitions, test conditions, and acceptance criteria.

Once finalized, SPADA recommendations, including method performance requirements and testing plans for PCR-based assays to detect F. tularensis and Y. pestis in aerosols, are submitted to and reviewed by the AOAC Methods Committee on Biological Threat Agents and the Official Methods Board (OMB) for adoption as AOAC technical guidelines.

AOAC will convene an expert review panel (ERP) to evaluate methods collected and recommend the best candidate method(s) for further evaluation and validation. AOAC will coordinate with Midwest Research Institute, which will perform independent laboratory testing of the candidate assay through the AOAC Research Institute’s Performance-Tested Methods^SM program. Then, method(s) successfully validated in multilaboratory testing—and with approval from the Methods Committee on Biological Threat Agents and the Official Methods Board--will be granted Official Methods of Analysis^SM status.

Full coverage of the most recent SPADA meeting is scheduled for the March/April 2009 issue of Inside Laboratory Management.

The next SPADA meeting is scheduled for April 14-15, 2009. For more information, or if you would like to be part of the work of SPADA, contact Deborah McKenzie, senior director, methods development and approval processes, at dmckenzie@aoac.org or Scott Coates, chief scientific officer, microbiology, and senior managing director, AOAC Research Institute, at scoates@aoac.org.

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