AOAC Approval for MIDI Anthrax Identification System

The Sherlock Microbial Identification System from MIDI, Inc. has been given AOAC Official Methods of AnalysisSM status for the confirmatory identification of Bacillus anthracis, the anthrax pathogen.

The comprehensive evaluation was conducted by AOAC INTERNATIONAL (formerly the Association of Official Analytical Chemists) and funded by the Department of Homeland Security. As an Official MethodSM, the MIDI Sherlock System may be used to confirm presumptive B. anthracis identifications from human and animal anthrax infections or from suspected environmental contamination following culture.

During the AOAC Study, the MIDI Sherlock System was subjected to exhaustive testing of geographically diverse strains of B. anthracis and related bacteria to determine its ability to differentiate among them. The 11 laboratories involved in the study reported an overall sensitivity for the identification of B. anthracis of 96.3 percent. Scientists at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) at Fort Detrick, MD contributed the anthrax data used in the MIDI Sherlock System.

Although the anthrax pathogen was the sole focus of the MIDI evaluation, the system also contains entries for other potential bioterrorism agents that cause diseases such as bubonic plague, tularemia, brucellosis, glanders and melioidosis.

The Sherlock Microbial Identification System identifies over 1,500 species of bacteria by automated analysis of the fatty acids in the bacterial cell membrane. The bacteria are identified by comparing their fatty acid “fingerprint” to databases of known fatty acid patterns. The system includes several bacterial databases, including The MIDI BIOTERTM database (version 2), which was exclusively used in the study.

The MIDI Sherlock System can identify more than 200 bacterial samples per day at a cost of less than $3.00 per sample for consumables and has proven effective for routine bacterial identifications at state health laboratories, major hospitals, government facilities and military installations worldwide.

It was used during the 2001 anthrax attacks and was the first system to identify the anthrax pathogen in the Connecticut case. Dr. Myron Sasser, President of MIDI stated, "This system doesn’t just sit on the shelf until a bioterrorism attack occurs. Rather, it is a laboratory-based system that can be used on a routine basis to identify commonly isolated bacteria from clinical and environmental sources, while at the same time proactively screening for potential agents of bioterrorism. Suspicion of a bioterrorism agent is not required for effective use of the system. With AOAC Official MethodsSM status, laboratories will now have a highly accurate confirmatory identification system that can be used for both routine bacterial identifications and potential anthrax attacks."