Clostridium novyi (oedematiens) a Gram-positive, endospore- forming, obligate anaerobic bacteria of the class Clostridia.

[4] Clostridium novyi is considered to be made up from three clades, labelled A, B and C, distinguished by the range of toxins they produce.

[5] Based on toxin production, Clostridium haemolyticum has been suggested to be considered a part of C. novyi, forming a separate type D in the genus.

Injection into dogs resulted in extreme oedema of the submucosal tissues of the duodenum while leaving the stomach uninjured.

[12] Alpha-toxins are glycosyltransferases, modifying and thereby inactivating different members of the Rho and Ras subfamily of small GTP-binding proteins.

[citation needed] The epsilon-toxin is characterised as lecithino-vitelin[check spelling] and thought to be responsible for the pearly layer found in cultures.

However, spores may escape from the gut and lodge in any part of the body and result in spontaneous infection should local anaerobic conditions occur.

[citation needed] Wound infection by C novyi and many other clostridium species cause gas gangrene[17] Spontaneous infection is mostly associated with predisposing factors of hematologic or colorectal malignancies and with diabetes mellitus,[18] although Gram-negative organisms, including Escherichia coli, may lead to a gas gangrene-like syndrome in diabetic patients.

Testing is problematical with figures presented by McLauchlin and Brazier [cited above] suggesting a false negative rate of about 40% under ideal conditions.