Isolation of Clostridium absonum and its cultural and biochemical properties

A new procedure for isolation of Clostridium absonum was devised. Sixtyseven strains of C. absonum were isolated from 135 soil samples, but no strain of C. absonum could be found from human fecal samples. The lecithinase, hemolysin, and lethal toxin in the culture filtrates of this species exhibited low avidity for C. perfringens type A antitoxin. The three activities were inseparable by the present method of purification. A reinvestigation of biochemical properties revealed that incomplete suppression of lecithinase reaction by C. perfringens type A antitoxin and no fermentation of raffinose, melibiose, and starch are useful criteria to differentiate C. absonum from C. perfringens, and that positive, although weak, gelatin liquefaction and fermentation of trehalose are useful to differentiate it from C. paraperfringens.