The Morphology and Ultrastructure of the Spore and Exosporium of Some Clostridium Species

Abstract

SUMMARYThe spores of original isolates of Clostridium species obtained from fresh and processed marine fish and from marine bottom deposits were compared with the spores of culture collection strains of the same species. These strains were Clostridium botulinum type E, C. sporogenes, C. bifermentans and C. sordellii.Spores of unclassified, non-toxigenic isolates which resemble C. botulinum type E, of '0s mutants', of culture collection strains of C. botulinum types A and B and an isolate of type F were also examined. The gross morphology and ultrastructure of the spores and exosporia were studied in electron microscopic preparations by using the techniques of metal shadowing, carbon replica, negative-staining and ultra-thin sectioning. Spores of some strains were found to possess tubular appendages. The morphology of the spores and the ultrastructural detail of the spore appendages and exosporia are described.

Lipid diversity among botulinum neurotoxin-producing clostridia

“…The only earlier report concerning the polar lipids of C. botulinum was on strain NCIB 4270 grown at 30 u C. This non-proteolytic strain, which was isolated by the Torry Research Station from sea-bottom deposits off the Scandinavian coast prior to 1967 (Hodgkiss et al, 1967), contained PE, PG, CL, phosphatidylserine and a phosphorus-containing glycolipid of unknown structure (Evans et al, 1998). None of these lipid classes had plasmalogen equivalents.…”

Isolation and Partial Characterization of Exosporium from Spores of a Highly Sporogenic Mutant of Clostridium botulinum Type A

“…The structure of exosporia of C. botulinum has a type-or strain-specific appearance (11,12,29). The exosporium of the highly sporogenic mutant AT2 derived from C. botulinum type A 190L possessed a relatively simple, lamellar structure, each lamella consisting of a hexagonal array with a center-to-center distance of about 9.5 nm.…”

“…The fine structure of the exosporia has been well documented using ultrathin sectioning (4, 7, 31), negative staining (12,19,32), and freeze-etching (13,26,32). The morphology of the spores and exosporia of Clostridium botulinum have been demonstrated by electron microscopy to vary according to toxigenic types and strains.…”

“…The spores of type A are covered by multilayered exosporia (6,28,29), whereas those of type B are enveloped by open-ended, sheathlike exosporia (29). The outstanding features of the spores of type E are the presence of numerous tubular appendages and the delicate fibrillar structure of the membraneous and large exosporia (11,12).…”

“…The spores of type A are covered by multilayered exosporia (6,28,29), whereas those of type B are enveloped by open-ended, sheathlike exosporia (29). The outstanding features of the spores of type E are the presence of numerous tubular appendages and the delicate fibrillar structure of the membraneous and large exosporia (11,12).The exosporia of Bacillus cereus (7,20) and Bacillus thuringiensis (25) were isolated from spores and examined in detail concerning their chemical composition. In contrast, little information on the morphological and chemical properties of exosporia from the genus Clostridium is available.…”