<prompt> The endotoxin of the following gram negative bacteria does not play any pa in the pathogenesis of the natural disease.E. coliE. coliVibrio choleraePseudomonas  <response>: Ans. is c i.e., Vibrio cholerae . Cholera vibrios possess the lipopolysaccharide 0 antigen LPS endotoxin, but it has no role in pathogenesis. About other options . Somatic lipopolysaccharide surface 0 antigen of E.coli has endotoxic activity and also protect the bacilli from phagocytosis . Long chain lipopolysaccharide endotoxin of klebsiella protects it from the action of serum complement . Endotoxin of pseudomonas causes fever, leukocytosis or leukopenia, shock, DIC, hypotension, ARDS, SIRS. 