Clostridium sporogenes
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster I (Clostridium sensu
Clostridium sporogenes  (Heller 1922) Bergey, Harrison, Breed, Hammer and Huntoon 1923.
Historical synonyms:
Bacillus sporogenes var. A Metchnikoff 1908,   Metchnikovillus
Heller 1922, Clostridium sporogenes var. A  (Metchnikoff) Prevot 1938.

Clostridium sporogenes can be differentiated from proteolytic strains of
C. botulinum
types A, B, and F, which it closely resembles phenotypically, by toxin neutralization in
mice, by polyacrylamide gel electrophoretic examination of soluble cellular proteins,
or by gas chromatography of trimethylsilyl derivatives of wholecell hydrolysates.
C. sporogenes and C. difficile also are morphologically similar and have similar
fermentation products; they differ, however, in mannitol fermentation, proteolytic activity
in milk and meat, and in lipase production.
Gram-positive, straight rods, 0.3-1.4 x 1.3-16.0 µm, occuring singly. Spores are oval,
subterminal, and swell the cell. The cell wall is susceptible to dissolution by
lysozyme. Motile by peritrichous flagella.
Surface colonies on blood agar plates are 2-6 mm in diameter,  usually beta-hemolytic, circular to irregular,  and a coarse rhizoid
margin, semiopaque/opaque, have a raised yellowish-gray center and a flattened periphery composed of entangled filaments
(“Medusa head” colony), matt surface, firmly adherent to the agar. On moist media, colonies are flat, thin, spreading. Colonies in agar
are spherical, with an opaque center, and a woolly semitranslucent periphery; lenticular colonies with fine marginal outgrowths may
be produced.
Cultures in PYG broth are turbid with a smooth or ropy to flocculent sediment and have a pH of 5.7-6.4  after incubation for 7 days. In
chopped-meat medium with iron filings, there is blackening of the meat particles. Abundant growth in nutrient, cooked meat broth,
with grayish yellow sediment.
Growth is variable in 6.5% NaCl, 20% bile, or at a pH of 8.5. Grow at temperature: 25 and 45 ºC, optimum 30-40 ºC. Good growth
occurs in an atmosphere containing up to 100% CO
2 . Abundant gas is produced in PYG deep agar cultures. Major products of
metabolism in PYG broth: acetic and butyric acids, ethanol and abundant H
2 . Acid production from carbohydrates often masked by
ammonia from amino acid deamination.
Isolated from soil, marine and fresh water lake sediment, preserved meat and dairy
products; snake venom; feces of sheep and dogs; human infant and adult feces;
infections in domestic animals; infections in humans including bacteremia, infective
endocarditis, central nervous system, and pleuropulmonary infections; abscesses;
war wounds; other pyogenic infections.

Susceptible to chloramphenicol, tetracycline, penicillin, doxycycline. Resistant to
streptomycin, neomycin, kanamycin, amikacin.
Some strains are capable of inhibiting growth and toxin production by
type A.

C. sporogenes strains can produce bacteriocin-like substances that are active
against other strains of
C. sporogenes.
Although Clostridium sporogenes  is isolated from infections, these infections are usually polymicrobial and the role, if any, of this
species as a pathogen in such infections has not been established. The highly proteolytic nature of
Clostridium sporogenes is
thought possibly to act as an adjuvant and promote invasiveness of other bacteria in various mixed infections of animals and humans
a generalized lethal disease, possibly egg-borne, in newly hatched chicks has been attributed to
C. sporogenes.
Is not pathogenic for laboratory animals. Toxin is not produced.
Three flagellar antigens, four somatic antigens, and four spore antigens are detected.
  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., 1975. 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.
  3. Macovei A., 2009. Identificarea bacteriilor anaerobe. In: Tratat de Microbiologie Clinica (Ed. Buiuc D. si Negut M.), editia a IIIa,
    Editura Medicala, Bucuresti, 900-927.
  4. Secasiu V., 2001. Boli produse de germeni din genul Clostridium. In: Boli infectioase ale animalelor, Moga Manzat R., Ed. Brumar,
    Timisoara, 481-612.
H2 is produced very abundantly. Milk reaction is variable. Meat digestion is positive.

Positive results for H
2 & H2S production, casein hydrolysis, chitinase, DN-ase, esculin hydrolysis, ferredoxin, gelatin hydrolysis, lipase,
neutral red reduction, thiaminase and substrate utilized and/or acid produced from glucose.

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

Variable results for resazurin reduction, hydrolysis of hippurate, urease, substrate utilized and/or acid produced from: fructose (weak),
glycerol & maltose (weak).
(c) Costin Stoica
Culture media
Biochemical tests
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