Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Bacillota (Firmicutes), Class Clostridia, Order Eubacteriales, Family Clostridiaceae, Genus Clostridium, Cluster I
(Clostridium sensu stricto), Clostridium putrefaciens (McBryde 1911) Sturges and Drake 1927.
Historical synonyms: Bacillus putrefaciens McBryde 1911, Palmula putrefaciens
(McBryde 1911) Prevot 1938, Acuformis putrefaciens (McBryde 1911) Prevot 1940.
Gram-positive, straight rods, 1.5-1.8 x 7.5-15 µm, occuring often as long curving
filaments, or singly, in pairs, in long chains, in tangled masses. Nonmotile. Spores
are round/oval, subterminal/terminal, and swell the cell. Sporulation occurs most
readily in chopped-meat cultures held at room temperature.
Surface colonies on blood agar plates are beta-hemolytic, pinpoint–4 mm, circular to
irregular, flat to low convex, transparent to translucent/opaque, colorless/gray, shiny,
and smooth/matt surface, with a slightly scalloped or rhizoid margin, and a crystalline
or mosaic internal structure.
Cultures in PYG broth are slightly turbid with a smooth sediment and have a pH of 7.0 after incubation under 90% N2 - 10% CO2 gas
for one week.
Slight to moderate growth in nutrient broth; better growth in cooked meat broth. Growth is inhibited in 6.5% NaCl or 20% bile.
Optimum temperature for growth is 15-22 ºC. Can grow at 30 ºC, but not at 37 ºC. Optimum pH 6.2-7.4, range 5.8-8.5. No gas is
detected in PYG deep agar cultures. Products in PYG broth are moderate amounts of acetate, formate, lactate, and succinate; no H2 is
produced.
Isolated from spoiled hams, hog muscle, chicken carcasses, human feces, urine specimens from pregnant women with bacteriuria.
Non-pathogenic for laboratory animals. Toxin is not formed.
- 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.
- 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 is negative. Meat is digested.
Positive results for ammonia production (weak), neutral red reduction and substrate utilization and/or acid production from glucose.
Negative results for casein hydrolysis, esculin hydrolysis, indole production, lecithinase, lipase, nitrate reduction, starch hydrolysis,
urease, Voges-Proskauer reaction, substrate utilization and/or acid production from: amygdalin, arabinose, cellobiose, dulcitol,
glycogen, inositol, inulin, lactose, maltose, mannitol, melezitose, melibiose, raffinose, rhamnose, ribose, salicin, sorbitol, starch,
sucrose and trehalose.
Variable and weak results for H2S production, substrate utilization and/or acid production from: fructose, galactose, mannose,
sorbose and xylose.
(c) Costin Stoica