Immunity protein component of a toxin-immunity protein module, which functions as a cellular contact-dependent growth inhibition (CDI) system. CDI modules allow bacteria to communicate with and inhibit the growth of closely related neighboring bacteria in a contact-dependent fashion. Neutralizes the toxic activity of cognate toxin CdiA (C-terminal 160 residue CT fragment) upon expression in E.coli. Does not inhibit toxic activity of CdiA from other strains of B.pseudomallei. Specifically interacts with cognate toxin CdiA, which inhibits the toxin.