Antibiotic susceptibility

Antibiotic susceptibility testing (AST) is a simple extension of identification, using the MicroPhage platform. Breakpoint susceptibility / resistance testing can be achieved in the use of most antibiotics in a parallel assay to the identification test. Antibiotics act faster on susceptible hosts than bacteriophage amplification, allowing for a simple means to determine bacterial response to the antibiotic. If the bacteria is determined to be present in the identification test, a positive in the antibiotic test determines it is a resistant organism, as the bacteria was not inhibited by the present antibiotic. Conversely, if the present bacteria produces no test line from the antibiotic test, then the user can interpret the organism as susceptible to that antibiotic. Unlike molecular assays, the MicroPhage test demonstrates phenotypic response to the antibiotic.

The process is again simple: A second parallel sample is taken or, if feasible, a single sample can be split into two equal specimens. One is added to the identification reagents, the other to the antibiotic susceptibility reagents, and both are set to incubate. Detection is run in parallel and lines are first read for bacterial identification, then antibiotic susceptibility / resistance.

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