Transitional Forms of Corynebacterium acnes in Disease

A clear-cut triad of sequential Corynebacterium acnes transitional forms from disease has been discovered. This entity includes three major forms which are capable of stabilization in culture, the spherical, the intermediate, and the definitive C. acnes. During conversion or reversion among the three forms, a variety of forms with mixed characteristics was observed. The spherical form was gram-negative and osmotically fragile, but it possessed a vestigial cell wall and mesosomes which excluded it from the L forms. In lieu of the L-form designation, the term "transitional" was adopted for all forms leading up to the definitive C. acnes. Culture of the spherical form was successful only on Mycoplasma-type media. The intermediate form was gram-negative, had mixed spherical and filamentous morphology, and bore a striking resemblance to Streptobacillus moniliformis. Like the spherical form, it was nutritionally exacting. The definitive form of C. acnes was preceded by gram-positive transitional forms of C. acnes morphology. It lacked, however, the carbohydrases and proteinases of C. acnes and susceptibility to C. acnes bacteriophages. Reversion was often blocked at this stage. A series of blood cultures from a patient with endocarditis was studied. Postmortem stain sections of the heart-valve lesion included intracellular masses of gram-negative spherical organisms. Indirect fluorescent antibody staining of these masses was strongly positive with antiserum to the spherical form and weakly positive with antiserum to the intermediate form.     

Tetracycline Inhibition of a Lipase from Corynebacterium acnes

A lipase which hydrolyzes triglycerides (tricaprylin and trilaurin) and naphthyl laurate was obtained from the broth of Corynebacterium acnes cultures by ammonium sulfate fractionation. Ca(2+) and sodium taurocholate stimulated activity of the enzyme. Ethylenediaminetetraacetic acid (EDTA) did not inhibit activity of the Ca(2+)-activated enzyme, but lipolytic activity was inhibited by EDTA in the absence of Ca(2+). Tetracycline (10(-4)m) produced a slight inhibition of the lipase activity with 5 x 10(-5)m or less showing no effect on the lipase activity. However, complete inhibition by tetracycline at 10(-4)m was observed for Ca(2+)-activated enzyme. Tetracycline inhibition of the C. acnes lipase could be demonstrated at concentrations as low as 10(-6)m.     

Cultural characteristics and fatty acid composition of Corynebacterium acnes

A detailed study of the cultural characteristics and cellular fatty acid composition of 27 isolates of Corynebacterium acnes was performed to establish the properties by which this organism may be identified and characterized. The fatty acids were extracted directly from whole cells and examined as methyl esters by gas-liquid chromatography. Each strain possessed a similar fatty acid profile which was characterized by a large percentage of C15 branched-chain acid. Uniformity in certain biochemical reactions and cultural characteristics was also observed. All strains were catalase-positive, nonmotile, and urease-negative, reduced nitrate, liquefied gelatin, failed to hydrolyze esculin and starch, and gave a positive methyl red test. Glucose, fructose, and glycerol were fermented, but not lactose, salicin, sucrose, maltose, xylose, or arabinose. Production of hydrogen sulfide and indole, fermentation of mannitol, and hemolytic activity were variable characteristics. Two species of the genus Propionibacterium were also tested and found to be similar to C. acnes both in cultural characteristics and fatty acid composition. The results strengthen previous suggestions that C. acnes should be classified in the genus Propionibacterium.     

Properties of Corynebacterium acnes Bacteriophage and Description of an Interference Phenomenon

Nine virulent bacteriophages of the anaerobe Corynebacterium (Propionibacterium) acnes, the P-a series, are DNA phages, with long, curved nonretractile tails (130 nm) without tail plates or fibers. They have isometric heads (420 by 460 nm), and are placed in Bradley's group B-1. There is permanent plaque suppression at highest phage concentrations. After 100- to 1,000-fold dilution, plaques are evident. The latent period is 1 h and burst size 25. Cross-neutralization data of antisera for the nine phages are similar. There is an unexplained precipitous drop in plaque-forming units during the first 5 min of neutralization, after which the rate is linear for 2 h. They are sensitive to pH extremes but are partially protected even at pH 4 or 9 by storage at 4 C. They are resistant to ether and chloroform and are inactivated within 10 min at 70 C.     

Two New Serological Groups of Actinomyces

Actinomyces odontolyticus and A. viscosus are designated as group E and group F in the serological grouping of the Actinomyces.     

Chemical and Immunological Studies on the Cell Walls of Propionibacterium acnes Strain C7 and Corynebacterium parvum ATCC 11829

The chemical and immunological properties of the cell walls prepared from the cells of anaerobic coryneforms, Propionibacterium acnes C7 and Corynebacterium parvum ATCC 11829, were partially investigated. The cell walls prepared from P. acnes C7 and C. parvum ATCC 11829 were composed of fatty acids, polysaccharides consisting glucose, galactose and mannose and mucopeptides consisting mainly of alanine, glutamic acid, a, ε-diaminopimelic acid, glycine, muramic acid and glucosamine. As the fatty acid constituents of the cell wall of P. acnes C7, iso-pentadecanoic acid and iso-heptadecanoic acid were detected as major components. Both cell walls prepared from P. acnes C7 and C. parvum ATCC 11829 showed potent adjuvant activity on the formation of circulating antibody and development of delayed type hypersensitivity in vivo and on the primary immune response to sheep erythrocytes in vitro, however, could not augment helper function of carrier-primed T cells and on the development of cell-mediated cytotoxicity to mastocytoma P815-X2 cells in C57BL/6J mice. It is also shown that the cell walls of P. acnes C7 and C. parvum ATCC 11829 act on mouse spleen cells as mitogen.     

Propionibacterium acnes

Propionibacterium acnes, a common skin organism, is most notably recognized for its role in acne vulgaris. It also causes postoperative and device-related infections and has been associated with a number of other conditions such as sarcoidosis and synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO), although its precise role as a causative agent remains to be determined. Propionibacterium acnes produces a number of virulence factors and is well known for its inflammatory and immunomodulatory properties. Recent publication of the P. acnes genome should provide further insights into the pathogenic capabilities of the organism and potentially lead to the development of new therapies.     

Enzymatic Basis for Differentiation of Rhizobium into Fast- and Slow-Growing Groups

Glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and other enzymes related to carbohydrate metabolism were studied in rhizobia. A nicotinamide adenine dinucleotide phosphate-6-phosphogluconate dehydrogenase was detected in strains of the fast-growing group of Rhizobium but not in strains of the slow-growing group. An enzymatic differentiation of rhizobia was established.