Evaluering av RAZOR™-instrument for identifisering av biologiske trusselstoffer

Upon a biological incident, it is crucial to identify or to outrule the presence of biological threat agents. PCR is a specific and rapid molecular technique commonly used for identification of DNA from biological threat agents. Robust and user-friendly PCR instruments for use in the field have been developed and such systems are commercially available. Such field instruments can aid in giving a preliminary identification of the presence of biological threat agents in a sample thereby assisting in initiating proper countermeasures and further handling of the incidence. FFI has tested and evaluated two PCR systems for use in the field; RAZORTM and RAZORTM EX BioDetection System. These systems are from BioFire Diagnostics, Inc. (Salt Lake City, UT, USA). RAZORTM utilizes the users’ own PCR reagents added to the system’s empty test pouches. FFI tested the instrument’s sensitivity in analysis of bacterial DNA from Bacillus anthracis (anthrax), Brucella maris (brucellose), Francisella tularensis (tularemia/rabbit fever), Salmonella enterica (salmonellosis), Yersinia pestis (plague), Burkholderia mallei (glanders) and Shigella flexneri (diarrhea), and also from Bacillus atrophaeus spores (stimulant for B. anthracis spores). The sensitivity was measured to be in the range of 10 to 10000 genome copies per ml for the different microorganisms. The achieved sensitivity is as good as or 10 times more/less sensitive than the values presented or referred to by the producer. RAZORTM EX was tested using the test panel “The 10® Target Screen Kit”developed for the system. The kit contains a reagent pouch with freeze dried PCR reagents including primers for testing of ten different biological threat agents in one test: Bacillus anthracis (anthrax), Brucella melitensis (brucellosis), Clostridium botulinum type A (botulism), Coxiella burnetii (Q fever), Escherichia coli O157 (hemorrhagic diarrhea), Francisella tularensis (tularemia/rabbit fever), Ricinus communis (ricin poisoning), Salmonella (salmonellosis), Variola virus (smallpox) and Yersinia pestis (plague). FFI tested the RAZORTM EX system for DNA from B. anthracis, C. botulinum type A, E. coli O157, F. tularensis, ricin, S. enterica, og Y. pestis. The results showed that the RAZORTM EX system could identify DNA from the different biological threat agents in a mixed sample. FFI tested and detected up to six biological threat agents in a single test. The RAZORTM EX instrument was also tested for its ability to identify B. atrophaeus (simulant for B. anthracis), S. enterica, E. coli O157, C. botulinum type A and B. anthracis, either as bacterial cells, spores or DNA in complex samples that contained the bacterial species either in pure cultures or in mixed samples. The selected complex samples were milk, wheat flour and soil. The results showed that all biological threat agents, except for C. botulinum type A spores, could be identified in the complex samples without a timeconsuming sample preparation of the test material. Even though the spore form of C. botulinum was not detected, there is reason to believe that cells in active growth would have been detected. The RAZORTM EX instrument is a robust, low weight, mobile and very user friendly instrument for identification of biological threat samples, also in complex samples. The instrument can be used in the field by non-specialists and the results obtained are easy to interpret. It takes only 30 minutes to test for the presence of all ten biological threat agents when using ”The 10® Target Screen Kit”. This time estimate also includes a preparatory step for the samples to be ready for analysis. Internal controls secure the quality of the results from the RAZORTM EX analysis system. Our studies indicate that RAZORTM EX is a very well suited instrument for use in the field and/or for mobile laboratories for both military and civilian users, and whenever there is a need for rapid analysis to obtain a preliminary identification of biological threat agents.