sentence: Toxicity / infectivity / pathogenicity studies As the available methods for testing dermal sensitisation are not suitable for testing microorganisms and there are no validated test methods for sensitisation by inhalation , Bacillus thuringiensis subsp. kurstaki strain PB 54 may have the potential to provoke sensitising reactions.Acute toxicity studies have been performed with either the Bacillus thuringiensis subsp. kurstaki strain PB 54 or the formulated product Belthirul .