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 301 residue CT fragment) upon expression in E.coli. Does not inhibit toxic activity of CdiA from other strains of B.pseudomallei. Expression of this cdiAIB locus in B.thailandensis confers protection against other bacteria carrying the locus; growth inhibition requires cellular contact. Specifically interacts with the truncated CT fragment of cognate toxin protein CdiA-2, which inhibits CdiA-2 tRNA nuclease activity.