Publisher Summary
This chapter discusses the characteristics of the pathogenic and related clostridia. The clostridia are anaerobic or microaerophilic bacilli, usually staining Gram-positively and producing spores that commonly distend the organism. Some species decompose protein or ferment carbohydrates, or have both activities. Some produce exotoxins and are pathogenic for man. With the general exception of Cl. botulinum, which is the causal organism of botulism in man and animals, all the clostridia listed are associated with wound infections. The chapter describes some characteristics of the commonly encountered clostridia from which the following useful items of information emerge: (1) gelatinase activity is not a particularly useful discriminating feature; (2) clostridia that are lactose fermenters are never strongly proteolytic; (3) apart from G. cochlearium, which is entirely inactive and is rarely encountered, G. tetani is the only non-saccharolytic, non-proteolytic species; (4) Cl. histolyticum and Cl. botulinum type G are the only species that are non-saccharolytic but strongly proteolytic; Cl. botulinum type G is rarely encountered; and (5) it is useful to note that all the clostridia are motile except Cl. perfringens, and that all are non-capsulated except Cl. Perfringens.