Clostridium cochlearium
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster I (Clostridium sensu
Clostridium cochlearium (Douglas, Fleming and Colebrook 1919) Bergey, Harrison, Breed, Hammer and Huntoon 1923.

Historical synonyms:
Bacillus cochlearius Douglas, Fleming and Colebrook in Bulloch et al. 1919, Clostridium lentoputrescens
Hartsell and Rettger 1934.
Gram-positive straight to slightly curved rods, 0.5-1.3 x 1.6-14.1 µm, occuring singly or
in pairs. Motile by peritrichous flagella. Spores are round to oval, terminal or
subterminal, swelling the cell; sporulation occurs readily both in broth media or on
solid media (blood agar plates or chopped-meat slants); three distinct spore coats
and tubular appendages attached to one end of the spore have been demonstrated.
Surface colonies on blood agar plates are 0.5-3.0 mm, circular to irregular, slightly
scalloped to lobate, flat to raised, translucent, gray-white, smooth, shiny, with a
mottled or mosaic internal structure. Hemolysis is variable. Cultures in PYG broth are
turbid with a smooth sediment and have a pH of 6.0-6.5  after incubation for 1 week.
Moderate to profuse growth in nutrient and cooked meat broths.
Growth is inhibited by 6.5% NaCl,  20% bile and at a pH of 8.5. Grows at 30-45 ºC,
weak growth at 25 ºC; optimum temperature 37 ºC.

Products in PYG broth: butyrate, acetate, abundant H
2 and propionate. Serine, aspartate, and histidine are utilized for growth.
Isolated from soil, human oral cavity, human and horse feces, wounds, crab meat. Susceptible to clindamycin, penicillin G,
erythromycin  and tetracycline.
Culture supernatants are nontoxic for mice. Non-pathogenic for laboratory animals. Toxin is not produced.
One strain isolated from human subgingival plaque degrades fibrinogen, possibly contributing to periodontal disease.
  1. 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,
    Springer, 738-828.
  2. Smith L.D.S. and Hobbs G., 1974. Genus III. Clostridium Prazmowski 1880. In: (Eds.) Buchanan R.E. and Gibbons N.E., Bergey’s
    Manual of Determinative Bacteriology, Eighth Edition, The Williams & Wilkins Company, Baltimore, 551-572.
Milk reaction and meat digestion are negative. Carbohydrates are not fermented.

Positive results for hydrogen production (very abundantly), ammonia production, H
2S production & neutral red reduction.

Negative results for casein hydrolysis, lecithinase, nitrate reduction, starch hydrolysis, Voges - Proskauer reaction, substrate utilized
and/or acid produced from: adonitol, amygdalin, arabinose, cellobiose, cellulose, dulcitol, erythritol, esculin, fructose, galactose,  
glucose, glycogen, glycerol, inositol, inulin, lactose, maltose, mannitol, mannose, melezitose, melibiose, raffinose, rhamnose, ribose,
salicin, sorbitol, sorbose, starch, sucrose, trehalose & xylose.

Variable results for gelatin hydrolysis (weak), hippurate hydrolysis & indole production.
(c) Costin Stoica
Culture media
Biochemical tests
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