Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster XIVa (non-Clostridium
sensu stricto), Clostridium scindens Morris, Winter, Cato, Ritchie and Bokkenheuser 1985.
Gram-positive, pleomorphic, straight to slightly curved rods, 0.5-0.7 x 1.0-2.5 μm;
occuring singly or in chains. Some coccus-shaped cells 0.4-0.6 μm are found. Non-
motile; many cells have fimbriae 3.0-3.5 nm in diameter, in clusters of 2-10. Spores
are terminal and distend the cell; spores are formed on chopped meat agar slants
incubated at 30 ºC for 3 weeks.
Obligately anaerobic. Chemoorganotrophic. Colonies are circular to slightly irregular,
smooth, grayish-white, convex, and 0.3-1mm diameter. Nonhemolytic to sheep and
rabbit erythrocytes. Culture in glucose broth is turbid, with a smooth sediment after
incubation for 24 h. A mucoid sediment formed after incubation for 48 h. Abundant
gas is produced in peptone-yeast extract-glucose (1%) agar.
Optimum temperature for growth is 42 ºC; good growth at 37-45 ºC. No growth at 50
ºC. Weak growth at 25 ºC.
Products in PYEG broth are acetic acid, ethanol and hydrogen.
Isolated from human feces. Cultures survive heat treatment at 80 ºC for 10 min. and absolute ethanol exposure for 30 min.
Resistant to chloramphenicol, clindamycin, erythromycin, and tetracycline. Sensitive to penicillin G.
- N.A. Logan and P. De Vos, 2009. Genus I. Clostridium Prazmowski 1880. In: (Eds.) P.D. Vos, G. Garrity, D. Jones, N.R. Krieg, W.
Ludwig, F.A. Rainey, K.-H. Schleifer, W.B. Whitman. Bergey’s Manual of Systematic Bacteriology, Volume 3: The Firmicutes,
- Morris G.N., Winter J., Cato E.P., Ritchie A.E. and Bokkenheuser, 1985. Clostridium scindens sp. nov., a Human Intestinal
Bacterium with Desmolytic Activity on Corticoids. IJSB vol.35, no.4, 478-481.
Milk reaction is negative. Meat is not digested. Produce desmolase. The desmolase cleaves the carbon-carbon bond of
17-hydroxylated corticoids at C17 - C20, thereby converting them to androstans (C19 steroids).
Positive results for desmolase, hydrogen production,H2S production, substrate utilization and/or acid production from: fructose,
glucose, lactose, mannose, ribose, and xylose.
Negative results for catalase, gelatin hydrolysis, indole production, lecithinase, lipase, nitrate reduction, esculin hydrolysis, starch
hydrolysis, substrate utilization and/or acid production from: amygdalin, arabinose, cellobiose, erythritol, esculin, galactose, glycogen,
inositol, maltose, mannitol, melezitose, melibiose, raffinose, rhamnose, salicin, sorbitol, starch, sucrose, and trehalose.
(c) Costin Stoica