RELATION OF PARTICLE SIZE OF C POLYSACCHARIDE COMPLEXES OF GROUP A STREPTOCOCCI TO TOXIC EFFECTS ON CONNECTIVE TISSUE

The component of Group A streptococci which is responsible for the chronic, remittent, multinodular lesion of connective tissue is derived from the cell wall. Further evidence is given to support the essential role of the group-specific C polysaccharide in the production of this lesion. A series of particles containing the group-specific C polysaccharide was prepared, ranging in size from large cell wall fragments to the relatively small hapten. A comparison of the lesion producing capacity of the particles in this spectrum revealed that maximum toxic activity is associated with C polysaccharide complexes of intermediate size. The discussion considers colloidal properties associated with C polysaccharide complexes of a certain size, and the influence particle size has on persistence in tissue, as possible explanations of the relationship between the size of the C polysaccharide complex and its ability to produce the chronic lesion of connective tissue.

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ANALYSIS OF THE EXPERIMENTAL LESION OF CONNECTIVE TISSUE PRODUCED BY A COMPLEX OF C POLYSACCHARIDE FROM GROUP A STREPTOCOCCI

Journal of Experimental Medicine ◽

10.1084/jem.116.1.17 ◽

1962 ◽

Vol 116 (1) ◽

pp. 17-28 ◽

Cited By ~ 14

Author(s):

John H. Schwab

Keyword(s):

Particle Size ◽

Cell Wall ◽

Active Sites ◽

Wall Structure ◽

Initial Reaction ◽

Skin Area ◽

Group A Streptococci ◽

Minimum Particle Size ◽

Group A ◽

Intracutaneous Injection

Specific antibody and a glucosaminidase enzyme react with the serologically active sites on C polysaccharide, and local injection of these reagents will neutralize the toxic effect of C polysaccharide complexes even after an interval of 24 to 72 hours. The cell wall lysins in S. albus filtrate and from phage-lysed Group C streptococci, break down the cell wall structure of Group A streptococci but leave the serological reactive sites of the C polysaccharide intact. These reagents lose much of their ability to neutralize the C polysaccharide toxin when superinjected after an interval of 4 hours following toxin injections. Toxic C polysaccharide cannot be recovered from an injection site by intercellular perfusion of the excised skin area after an interval of 1 to 4 hours following toxin injection. It is concluded that toxic particles of C polysaccharide complexes combine firmly with the dermal tissue of rabbits within 1 to 4 hours following intracutaneous injection. The cell wall lysins neutralize the toxin by reducing the particle size of C polysaccharide complexes. This minimum particle size is required for the initial reaction with tissue and when this has occurred these reagents are no longer able to influence the development of the lesion.

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Effect of grain size on the vapour phase hydration of monoclinic and triclinic modifications of tricalcium silicate; role of high temperature activation

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19911993 ◽

1991 ◽

Vol 56 (10) ◽

pp. 1993-2008

Author(s):

S. Hanafi ◽

G. M. S. El-Shafei ◽

B. Abd El-Hamid

Keyword(s):

Particle Size ◽

Vapour Phase ◽

Tricalcium Silicate ◽

Active Centers ◽

Thermally Activated ◽

Grain Sizes ◽

Intermediate Size ◽

Surface Active ◽

Temperature Activation

The hydration of tricalcium silicate (C3S) with three grain sizes of monoclinic (M) and triclinic (T) modifications and on their thermally activated samples were investigated by exposure to water vapour at 80°C for 60 days. The products were investigated by XRD, TG and N2 adsorption. The smaller the particle size the greater was the hydration for both dried and activated samples from (M). In the activated samples a hydrate with 2θ values of 38.4°, 44.6° and 48.6° could be identified. Hydration increased with particle size for the unactivated (T) samples but after activation the intermediate size exhibited enhanced hydration. Thermal treatment at 950°C of (T) samples increased the surface active centers on the expense of those in the bulk. Changes produced in surface texture upon activation and/or hydration are discussed.

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THE LYSIS OF GROUP A HEMOLYTIC STREPTOCOCCI BY EXTRACELLULAR ENZYMES OF STREPTOMYCES ALBUS

Journal of Experimental Medicine ◽

10.1084/jem.96.6.569 ◽

1952 ◽

Vol 96 (6) ◽

pp. 569-580 ◽

Cited By ~ 63

Author(s):

Maclyn McCarty

Keyword(s):

Cell Wall ◽

Extracellular Enzymes ◽

Group A Streptococci ◽

Carbohydrate Component ◽

Streptococcal Cell Wall ◽

Intact Cells ◽

Enzymatic Lysis ◽

Streptomyces Albus ◽

Group A ◽

Isolated Cell

Cell wall preparations of uniform chemical constitution have been obtained from several strains of group A streptococci. The isolated cell walls are dissolved by the same fractions of the Streptomyces albus enzymes that are effective in the lysis of intact cells, and it is likely that enzymatic lysis of group A streptococci is effected by an attack on the cell wall. The streptococcal cell wall, as prepared in this study, consists of approximately two-thirds carbohydrate and one-third protein. Small amounts of other components may be present. The carbohydrate component, which is composed primarily of N-acetyl-glucosamine and rhamnose, is the group-specific C carbohydrate. The evidence indicates that one of the streptomyces enzymes is directed toward the carbohydrate component of the cell wall.

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Electron microscopy of the replicative events of A25 bacteriophages in group A streptococci

Canadian Journal of Microbiology ◽

10.1139/m72-015 ◽

1972 ◽

Vol 18 (1) ◽

pp. 93-96 ◽

Cited By ~ 3

Author(s):

S. E. Read ◽

R. W. Reed

Keyword(s):

Electron Microscopy ◽

Cell Wall ◽

Electron Microscope ◽

Nucleic Acid ◽

Group A Streptococcus ◽

Group A Streptococci ◽

Virulent Phage ◽

Acid Pool ◽

Group A ◽

A Cell

The replicative events of a virulent phage (A25) infection of a group A Streptococcus (T253) were studied using the electron microscope. The first intracellular evidence of phage replication in a cell occurred 30 min after infection with arrest of cell division and increase in the nucleic acid pool. Phage heads were evident in the nucleic acid pool of the cells 45 min after infection. Release of phages occurred by splitting of the cell wall along discrete lines. This appeared to be at sites of active wall synthesis, i.e., near the region of septum formation. Many phage components were released but relatively few complete phages indicating a relatively inefficient replicative system.

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Role of Non-Group A Streptococci in Acute Pharyngitis

The Journal of the American Board of Family Medicine ◽

10.3122/jabfm.2009.06.090035 ◽

2009 ◽

Vol 22 (6) ◽

pp. 663-669 ◽

Cited By ~ 16

Author(s):

J. Tiemstra ◽

R. L. F. Miranda

Keyword(s):

Group A Streptococci ◽

Acute Pharyngitis ◽

Group A

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Occurrence of cross-resistance and β-lactam seesaw effect in glycopeptide-, lipopeptide- and lipoglycopeptide-resistant MRSA correlates with membrane phosphatidylglycerol levels

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz562 ◽

2020 ◽

Vol 75 (5) ◽

pp. 1182-1186 ◽

Cited By ~ 1

Author(s):

Kelly M Hines ◽

Tianwei Shen ◽

Nathaniel K Ashford ◽

Adam Waalkes ◽

Kelsi Penewit ◽

...

Keyword(s):

Cell Wall ◽

Susceptibility Testing ◽

Membrane Lipid ◽

Cross Resistance ◽

Membrane Composition ◽

Membrane Lipid Composition ◽

Usa300 Strain ◽

Associated Proteins ◽

The Relationship

Abstract Background Glycopeptides (GPs), lipopeptides (LPs) and lipoglycopeptides (LGPs) are related antimicrobials important for the management of invasive MRSA infections. Cross-resistance among these antibiotics in MRSA is well documented, as is the observation that susceptibility of MRSA to β-lactams increases as susceptibility to GPs and LPs decreases (i.e. the seesaw effect). Efforts to understand the relationship between GP/LP/LGP cross-resistance and the seesaw effect have focused on the PBPs, but the role of lipid metabolism has not been investigated. Objectives Since the cell membrane is structurally and metabolically integrated with the cell wall and anchors associated proteins, including PBPs, we examined the relationship between membrane lipid composition and the phenomena of cross-resistance among GPs/LPs/LGPs and the β-lactam seesaw effect. Methods We selected for daptomycin, vancomycin and dalbavancin resistance using the USA300 strain JE2 and evaluated the resulting mutants by WGS, MS-based lipidomics and antimicrobial susceptibility testing to assess the relationship between membrane composition, cross-resistance, and the seesaw effect. Results We observed cross-resistance to GPs/LPs/LGPs among the selected strains and the seesaw effect against various β-lactams, depending on the PBP targets of the particular β-lactam. We found that modification of membrane composition occurs not only in daptomycin-selected strains, but also vancomycin- and dalbavancin-selected strains. Significantly, we observed that the abundance of most phosphatidylglycerols positively correlates with MICs of GPs/LPs/LGPs and negatively correlates with the MICs of β-lactams. Conclusions These studies demonstrate a major association between membrane remodelling, cross-resistance and the seesaw effect.

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Streptococcal pharyngitis in general practice. 2. A note on dual infection and transient urinary abnormalities

Epidemiology and Infection ◽

10.1017/s0950268800050159 ◽

1992 ◽

Vol 109 (2) ◽

pp. 191-197 ◽

Cited By ~ 2

Author(s):

P. M. Higgins

Keyword(s):

General Practice ◽

Clinical Evidence ◽

Dual Infection ◽

Streptococcal Pharyngitis ◽

Microscopic Haematuria ◽

Group A Streptococci ◽

Group A ◽

Post Streptococcal Glomerulonephritis ◽

Urinary Abnormalities

SUMMARYIn an uncompleted study in 1965 microscopic haematuria in the second or third week after acute pharyngitis was found four times more often in patients with either microbiological or clinical evidence of dual infection with both group A streptococci and a virus than in patients with evidence only of infection with group A streptococci.Prospective studies of the role of viruses in the aetiology of transient haematuria and of acute post streptococcal glomerulonephritis are feasible in general practice and would be most productive if concentrated in children 5–9 years of age.

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Doubly Branched Hexasaccharide Epitope on the Cell Wall Polysaccharide of Group A Streptococci Recognized by Human and Rabbit Antisera

Infection and Immunity ◽

10.1128/iai.73.10.6383-6389.2005 ◽

2005 ◽

Vol 73 (10) ◽

pp. 6383-6389 ◽

Cited By ~ 12

Author(s):

Francis Michon ◽

Samuel L. Moore ◽

John Kim ◽

Milan S. Blake ◽

France-Isabelle Auzanneau ◽

...

Keyword(s):

Cell Wall ◽

Rabbit Antiserum ◽

Cell Wall Polysaccharide ◽

Group A Streptococci ◽

Group B Streptococci ◽

Group A ◽

Streptococcal Polysaccharide ◽

Synthetic Oligosaccharides ◽

Group B ◽

Dominant Epitope

ABSTRACT A number of epitope specificities associated with the cell wall polysaccharide antigen of group A streptococci were identified in a polyclonal rabbit antiserum induced in rabbits by whole group A streptococci and in polyclonal convalescent human antisera from children that had recovered from streptococcal A infections. The identification was achieved by using a series of synthetic oligosaccharides, glycoconjugates, and bacterial polysaccharide inhibitors to inhibit the binding of the group A helical polysaccharide to the polyclonal antisera. The exclusively dominant epitope expressed in the convalescent human antisera was the doubly branched extended helical hexasaccharide with the structure α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap(1→3)α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap. The hexasaccharide epitope also bound with the highest immunoreactivity to the rabbit antiserum. In contrast, the human antisera did not show significant binding to the singly branched pentasaccharide with the structure α-l-Rhap(1→2)α-l-Rhap(1→3)α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap or the branched trisaccharide α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap, although both these haptens bound significantly to the same rabbit antiserum, albeit with less immunoreactivity than the hexasaccharide. Inhibition studies using streptococcal group A and B rabbit antisera and the inhibitors indicated above also suggested that the group A carbohydrate, unlike the group B streptococcal polysaccharide, does not contain the disaccharide α-l-Rhap(1→2)α-l-Rhap motif at its nonreducing chain terminus, stressing the importance of mapping the determinant specificities of these two important streptococcal subcapsular group polysaccharides to fully understand the serological relationships between group A and group B streptococci.

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