ABSTRACT
During screening of Bacillus thuringiensis isolates for nematicidal activity it was observed that spores of B. thuringiensis germinated in the intestine of bacteriophagous nematodes in the presence of antibiotics. This phenomenon was studied more closely by scanning electron microscopy. The nematodes were fed with bacterial spore-crystal mixtures in axenic culture medium supplemented with tetracyclin and chloramphenicol. Germination of spores was rare but was more frequently observed in Panagrellus redivivus than in other nematode species investigated. Germination of spores in the nematode intestine resulted in the colonization of the entire nematode within 24 hr. Crude nematode tissue preparations supported germination and subsequent growth of B. thuringiensis spores and vegetative cells. The mechanism for the loss of antibiotic activity in the nematode intestine is unknown. Since B. thuringiensis requires a nutrient-rich environment for reproduction, e.g., a cadaver, bacteriophagous nematodes may serve as suitable hosts for B. thuringiensis.
Subject(s)
Bacillus thuringiensis/physiology , Rhabditida/microbiology , Animals , Microscopy, Electron, Scanning , Rhabditida/ultrastructure , Spores, Bacterial/physiologyABSTRACT
High resolution CT has become crucial to the definite diagnosis, accurate localisation and extension of benign spinal tumors. An osteoid osteoma mostly suspected by X-ray or scintigraphy, located in the axial skeleton--mainly of spongious content and with a complex anatomical structure--will be definitely more distinctly visualized on CT. Post-operative evaluation also requires CT.
