Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster I (Clostridium sensu
stricto), Clostridium sardiniense corrig. Prevot 1938, emend. Wang, Maegawa, Karasawa, Ozaki and Nakamura 2005.
Historical synonyms: Clostridium absonum Nakamura S., Shimamura T., Hayase M. and Nishida S., 1973.
Gram-positive straight or slightly curved rods, 0.5-1.7 x 1.0-10.0 µm, occurring singly,
in pairs or in short chains. Motile by peritrichous flagella; motility may be lost on
subculture. Spores are oval, subterminal/terminal; very few spores are produced in
usual media. Sporulation occurs most readily in 3-week-old chopped-meat broth
Surface colonies on blood agar plates are beta-hemolytic, 1-3 mm in diameter,
circular to irregular, raised or low convex, translucent or semiopaque, gray-white,
shiny, and smooth, with a lobate or erose margin and usually with a granular or
mottled internal structure. Cultures in PYG broth are turbid with a smooth or stringy
sediment and have a pH of 4.5–5.0 after incubation for 5 days.
Optimum temperature for growth is 25-37 ºC. Weak growth at 45 ºC. Growth is
stimulated by fermentable carbohydrates and inhibited by 6.5% NaCl. Abundant gas
is detected in PYG deep agar cultures. Products in PYG broth include large amounts
of acetic, butyric, and lactic acids; abundant hydrogen is produced.
Isolated from lesions of symptomatic anthrax in sheep, soil, water, feces of infants. Susceptible to chloramphenicol, penicillin G, and
Cultures injected subcutaneously or intramuscularly are pathogenic for sheep, guinea pigs, goats, dogs, rabbits, mice, rats, and
chickens. Culture supernatants are not toxic for mice.
- 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,
- Wang X., Maegawa T., Karasawa T., Ozaki E. and Nakamura S., 2005. Clostridium sardiniense Prevot 1938 and Clostridium
absonum Nakamura et al. 1973 are heterotypic synonyms: evidence from phylogenetic analyses of phospholipase C and 16S
rRNA sequences, and DNA relatedness. IJSEM 55, 1193-1197.
- NAKAMURA (S.), SHIMAMURA (T.), HAYASE (M.) and NISHIDA (S.): Numerical taxonomy of saccharolytic clostridia, particularly
Clostridium perfringens-like strains: descriptions of Clostridium absobnum sp. n. and Clostridium paraperfringens. International
Journal ofSystematic Bacteriology, 1973, 23, 419-429.
Milk reaction is positive (curd production). Meat is not digested.
Positive results for hydrogen production, ammonia production, esculin hydrolysis, lecithinase, neutral red reduction, resazurin
reduction, substrate utilization and/or acid production from: cellobiose, fructose, galactose, glucose, lactose, maltose, mannose,
salicin & sucrose.
Negative results for indole production, lipase, substrate utilization and/or acid production from: amygdalin, arabinose, glycogen,
inositol, inulin, mannitol, melezitose, melibiose, raffinose, rhamnose, sorbitol & xylose.
Variable results for nitrate reduction, starch hydrolysis, substrate utilization and/or acid production from: ribose, starch (weak) &
(c) Costin Stoica