Bacillus thuringiensis serotype H34 isolated from human and insecticidal strains serotypes 3a3b and H14 can lead to death of immunocompetent mice after pulmonary infection

In 1995, we isolated a strain of Bacillus thuringiensis serotype H34 from s evere human tissue necrosis. This bacterium was able to induce myonecrosis in immunosuppressed mice after cutaneous infection. Its potential pathogeni city for immunocompetent hosts was investigated in a mouse model of pulmona ry infection. Mice infected intranasally by a suspension containing 10(8) s pores died within 8 h in a clinical toxic-shock syndrome. In the same condi tions, infection with a mutant without crystalline toxin, with the supernat ant from a culture containing 10(8) bacteria ml(-1) and by the insecticidal strain serotypes 3a3b or H14 led to identical results. Lower inocula simpl y induced a local inflammatory reaction with bacterial persistence observed during the course of 10 days. (C) 1999 Federation of European Microbiologi cal Societies. Published by Elsevier Science B.V. All rights reserved.