scholarly journals FACTORS AFFECTING THE YIELD OF SPECIFIC ENZYME IN CULTURES OF THE BACILLUS DECOMPOSING THE CAPSULAR POLYSACCHARIDE OF TYPE III PNEUMOCOCCUS

1932 ◽  
Vol 55 (3) ◽  
pp. 377-391 ◽  
Author(s):  
René Dubos
Keyword(s):  
Capsular Polysaccharide ◽  
Free Enzyme ◽  
Appreciable Amount ◽  
Specific Substrate ◽  
Specific Enzyme ◽  
Factors Affecting ◽  
Type Iii ◽  
Cultural Conditions ◽  
Bacterial Enzyme ◽  
Specific Substance

All improved method is described for the preparation, concentration, and purification of a bacterial enzyme capable of decomposing the capsular polysaccharide of Type III Pneumococcus. The cultural conditions for the growth of the specific microorganism must be such that the capsular polysaccharide is completely decomposed before any appreciable amount of free enzyme is released into the medium. This reduces to a minimum the decomposition of the specific substrate by the free enzyme. As a result, a larger part of the specific substance remains as a source of energy for the growing microorganism and less enzyme is lost through inactivation during the course of decomposition of the specific substrate. A marked stimulation of growth and of enzyme production occurs when small amounts of yeast extract are added to the medium and when the cultures are incubated under conditions of increased aeration. Special emphasis is placed upon the fact that, thus far, appreciable amounts of the specific enzyme have been obtained only when the capsular polysaccharide itself, or the aldobionic acid derived from it, was present in the culture medium.

scholarly journals THE PROTECTIVE ACTION OF A SPECIFIC ENZYME AGAINST TYPE III PNEUMOCOCCUS INFECTION IN MICE

1931 ◽  
Vol 54 (1) ◽  
pp. 73-89 ◽  
Author(s):  
Oswald T. Avery ◽  
René Dubos
Keyword(s):  
Capsular Polysaccharide ◽  
Protective Action ◽  
Specific Enzyme ◽  
Animal Body ◽  
Type Iii ◽  
Bacterial Enzyme ◽  
Virulent Type ◽  
Favorable Influence ◽  
Living Organisms

The bacterial enzyme which decomposes the purified capsular polysaccharide of Type III Pneumococcus in vitro also destroys the capsules of the living organisms growing in media and in the animal body. Potent preparations of this same enzyme protect mice against infection with virulent Type III Pneumococcus. The protective action is type-specific. The protective activity of the specific enzyme is destroyed by heat (70°C. for 10 minutes). The enzyme remains in an effective concentration 24 to 48 hours after its injection into normal mice. The enzyme has been found to exert a favorable influence on the outcome of an infection already established at the time of treatment. A definite relationship has been found to exist between the activity of the enzyme in vitro and its protective power in the animal body. The mechanism of the protective action is discussed with special reference to the relation between the decapsulation of the bacteria by the enzyme and the phagocytic response of the host.

scholarly journals STUDIES ON THE QUANTITATIVE ACTION OF A SPECIFIC ENZYME IN TYPE III PNEUMOCOCCUS DERMAL INFECTION IN RABBITS

1932 ◽  
Vol 56 (4) ◽  
pp. 521-530 ◽  
Author(s):  
Kenneth Goodner ◽  
René Dubos
Keyword(s):  
Capsular Polysaccharide ◽  
Specific Enzyme ◽  
Type Iii ◽  
Definite Relationship

The enzyme which specifically decomposes the capsular polysaccharide of Type III Pneumococcus must be used in certain definite amounts in order to bring about the recovery of rabbits infected intradermally with this organism. The experiments reported in this paper indicate that the minimal amounts of enzyme required bear a definite relationship to the severity of the infection as gauged by the number of pneumococci present in the circulating blood.

scholarly journals THE USE OF GRADED COLLODION MEMBRANES FOR THE CONCENTRATION OF A BACTERIAL ENZYME CAPABLE OF DECOMPOSING THE CAPSULAR POLYSACCHARIDE OF TYPE III PNEUMOCOCCUS

1935 ◽  
Vol 62 (2) ◽  
pp. 271-279 ◽  
Author(s):  
René Dubos ◽  
Johannes H. Bauer
Keyword(s):  
Capsular Polysaccharide ◽  
Average Pore Size ◽  
Practical Method ◽  
Active Principle ◽  
Physiological Salt Solution ◽  
Optimal Conditions ◽  
Average Pore ◽  
Type Iii ◽  
Crude Enzyme Preparation ◽  
Bacterial Enzyme

1. The enzyme which decomposes the capsular polysaccharide of Type III Pneumococcus is associated with a protein which under optimal conditions of filtration passes through membranes with an average pore size of 10.6 mµ but is held back by pores having a diameter of 8.2 mµ. 2. When enzyme solutions are filtered to dryness through membranes of such porosity as to hold back the active principle, and when proper precautions are taken to prevent or minimize adsorption, the enzyme can be completely recovered in solution by immersing the membrane in distilled water or physiological salt solution. 3. These results are discussed with reference to the dimensions of the enzyme particle, and to the purification obtained in the course of ultrafiltration. 4. A practical method is described for the concentration and purification of the crude enzyme preparation by the use of graded collodion membranes.

scholarly journals DECOMPOSITION OF THE CAPSULAR POLYSACCHARIDE OF PNEUMOCOCCUS TYPE III BY A BACTERIAL ENZYME

1931 ◽  
Vol 54 (1) ◽  
pp. 51-71 ◽  
Author(s):  
René Dubos ◽  
Oswald T. Avery
Keyword(s):  
Enzyme Preparation ◽  
Capsular Polysaccharide ◽  
Peat Soil ◽  
Minimal Amount ◽  
Strictly Aerobic ◽  
Type I ◽  
Bacterial Cells ◽  
Type Iii ◽  
Specific Substance ◽  
Specific Polysaccharide

1. An organism has been isolated from peat soil which decomposes the specific capsular polysaccharide of Type III Pneumococcus. 2. The isolation has been made possible by the use of a synthetic mineral medium containing the specific polysaccharide as sole source of carbon. By repeated transfers in this medium the potential capacity of the organism to decompose the specific substance has been progressively increased. 3. The organism is a pleomorphic bacillus, motile and spore-bearing, exhibiting metachromatic granules; its reaction to the Gram stain varies according to the medium on which it is grown. It is strictly aerobic and grows well in plain broth and peptone solutions; it does not produce gas in any media and it forms small amounts of acid only on dextrin, galactose, lactose, salicin, and trehalose; its growth is inhibited by glucose. 4. The organism decomposes the capsular polysaccharide of Type III Pneumococcus aerobically, between pH 6.2 and 7.8, at room temperature and at 37.5°C., but not at 54°C. The decomposition of the specific substance is inhibited by the presence in the medium of other nutrients, such as peptones, which act as a more readily available source of energy. The action of the organism is specific; it does not attack the soluble specific substance of Type I or Type II Pneumococcus, nor any of the other bacterial polysaccharides thus far tested. 5. The organism possesses an endocellular enzyme. This enzyme has been extracted by autolysis of the bacterial cells; in sterile solution it exhibits the same specific action as do the organisms from which it is derived, decomposing only the capsular polysaccharide of Type III Pneumococcus. 6. This enzyme decomposes the Type III specific polysaccharide under anaerobic as well as under aerobic conditions; it is inactivated at 60–65°C.; the rate of decomposition of the specific substance is not affected by the presence of normal serum. 7. There exists a quantitative relationship between the total amount of specific substance decomposed and the amount of enzyme preparation used; the existence of this relation makes it possible to express the activity of a given enzyme preparation in terms of the minimal amount required for the complete decomposition of a given amount of specific substance. 8. The specific decomposition of the capsular polysaccharide of Type III Pneumococcus, by the organism as well as by the enzyme it produces, illustrates once more the specificity of the types of Pneumococcus and confirms the fact that the capsular polysaccharides, and not some impurities carried along with them, are responsible for type specificity.

scholarly journals THE ACTION OF A SPECIFIC ENZYME UPON THE DERMAL INFECTION OF RABBITS WITH TYPE III PNEUMOCOCCUS

1932 ◽  
Vol 55 (3) ◽  
pp. 393-404 ◽  
Author(s):  
Kenneth Goodner ◽  
René Dubos ◽  
Oswald T. Avery
Keyword(s):  
Capsular Polysaccharide ◽  
Early Termination ◽  
Specific Enzyme ◽  
Type Iii ◽  
Experimental Disease

The action of the enzyme which specifically decomposes the capsular polysaccharide of Type III Pneumococcus has been tested in Type III pneumococcus dermal infections in rabbits. When injected in sufficient amounts, this enzyme is capable of bringing about a favorable and early termination of the experimental disease which ordinarily is fatal in nearly all instances. The results of the present study yield further evidence that the capsular substance is of great importance in pneumococcus infection, since, in so far as known, the only action of which the specific enzyme is capable is that of decomposing the capsular polysaccharide.

scholarly journals The Serotype of Type Ia and III Group B Streptococci Is Determined by the Polymerase Gene within the Polycistronic Capsule Operon

2000 ◽  
Vol 182 (16) ◽  
pp. 4466-4477 ◽  
Author(s):  
Donald O. Chaffin ◽  
Stephen B. Beres ◽  
Harry H. Yim ◽  
Craig E. Rubens
Keyword(s):  
Capsular Polysaccharide ◽  
Single Gene ◽  
Functional Characterization ◽  
Neonatal Morbidity ◽  
Polymerase Gene ◽  
Chromosomal Dna ◽  
Group B Streptococci ◽  
Sequence Comparisons ◽  
Type Iii ◽  
Type Ia

ABSTRACT Streptococcus agalactiae is a primary cause of neonatal morbidity and mortality. Essential to the virulence of this pathogen is the production of a type-specific capsular polysaccharide (CPS) that enables the bacteria to evade host immune defenses. The identification, cloning, sequencing, and functional characterization of seven genes involved in type III capsule production have been previously reported. Here, we describe the cloning and sequencing of nine additional adjacent genes, cpsIIIFGHIJKL,neuIIIB, and neuIIIC. Sequence comparisons suggested that these genes are involved in sialic acid synthesis, pentasaccharide repeating unit formation, and oligosaccharide transport and polymerization. The type III CPS (cpsIII) locus was comprised of 16 genes within 15.5 kb of contiguous chromosomal DNA. Primer extension analysis and investigation of mRNA from mutants with polar insertions in their cpsIII loci supported the hypothesis that the operon is transcribed as a single polycistronic message. The translated cpsIII sequences were compared to those of the S. agalactiae cpsIa locus, and the primary difference between the operons was found to reside in cpsIIIH, the putative CPS polymerase gene. Expression of cpsIIIH in a type Ia strain resulted in suppression of CPS Ia synthesis and in production of a CPS which reacted with type III-specific polyclonal antibody. Likewise, expression of the putative type Ia polymerase gene in a type III strain reduced synthesis of type III CPS with production of a type Ia immunoreactive capsule. Based on the similar structures of the oligosaccharide repeating units of the type Ia and III capsules, our observations demonstrated that cpsIaH andcpsIIIH encoded the type Ia and III CPS polymerases, respectively. Additionally, these findings suggested that a single gene can confer serotype specificity in organisms that produce complex polysaccharides.

Initial Studies of the Molecular Basis of Peptide Mimicry of Group B Streptococcal Type III Capsular Polysaccharide

2001 ◽  
Vol 20 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Seth H. Pincus ◽  
Stephen R. Lepage ◽  
Robert F. Jung ◽  
Jennifer G. Massey ◽  
Mahesh Jaseja
Keyword(s):  
Molecular Basis ◽  
Capsular Polysaccharide ◽  
Type Iii ◽  
Peptide Mimicry ◽  
Group B

scholarly journals Polysaccharides and virulence of Burkholderia pseudomallei

2007 ◽  
Vol 56 (8) ◽  
pp. 1005-1010 ◽  
Author(s):  
M. Sarkar-Tyson ◽  
J. E. Thwaite ◽  
S. V. Harding ◽  
S. J. Smither ◽  
P. C. F. Oyston ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Capsular Polysaccharide ◽  
Gene Clusters ◽  
Type I ◽  
Wild Type ◽  
Time To Death ◽  
Type Iii ◽  
Type Iv ◽  
Mutant Strains ◽  
Delayed Time

Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease of humans and animals. Gene clusters which encode capsular polysaccharide (type I O-PS) and LPS (type II O-PS), both of which play roles in virulence, have previously been identified. Here, the identification of two further putative clusters, type III O-PS and type IV O-PS, is reported. Mice challenged with type III O-PS or type IV O-PS mutants showed increased mean times to death (7.8 and 11.6 days) compared to those challenged with wild-type B. pseudomallei (3 days). To investigate the possible roles of polysaccharides in protection, mice were immunized with killed cells of wild-type B. pseudomallei or killed cells of B. pseudomallei with mutations in the O antigen, capsular polysaccharide, type III O-PS or type IV O-PS gene clusters. Immunization with all polysaccharide mutant strains resulted in delayed time to death compared to the naïve controls, following challenge with wild-type B. pseudomallei strain K96243. However, immunization with killed polysaccharide mutant strains conferred different degrees of protection, demonstrating the immunological importance of the polysaccharide clusters on the surface of B. pseudomallei.

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