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

2005 ◽  
Vol 73 (10) ◽  
pp. 6383-6389 ◽  
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.

scholarly journals Synergistic hemolysis phenomenon shown by an alpha-toxin-producing Clostridium perfingens and streptococcal CAMP factor in presumptive streptococcal grouping

1978 ◽  
Vol 8 (5) ◽  
pp. 480-488
Author(s):  
S M Gubash
Keyword(s):  
Human Blood ◽  
Test Group ◽  
Blood Agar ◽  
Group A Streptococci ◽  
Alpha Toxin ◽  
Group B Streptococci ◽  
Camp Factor ◽  
Group A ◽  
Camp Test ◽  
Group B

A new phenomenon of synergistic hemolysis by Clostridium perfringens alpha-toxin and the streptococcal CAMP factor on human and guinea pig erythrocytes is described. A possible mode of action of the CAMP factors is suggested. On human blood agar all of the tested isolates of group B streptococci gave an arrowhead-shaped zone of hemolysis; 74% of group A gave a crescent-shaped lytic zone, whereas all isolates of groups C and G and the remaining 26% of group A streptococci gave a bullet-shaped lytic zone. By comparison, in the CAMP test incubated aerobically and anaerobically, 70 and 91%, respectively, of streptococci other than group B gave positive, arrowhead-shaped lytic zones. If all intermediate positive reactions in the CAMP tests were read as negative after aerobic incubation, only 89% of group B streptococci would be properly identified. The synergistic hemolysis phenomenon, using an alpha-toxin-producing C. perfringens and human blood agar, provided a reliable test for presumptive identification of group B streptococci, with promising potential to differentiate in the same test group A streptococci from other groups.

scholarly journals STUDIES ON STREPTOCOCCUS PYOGENES

1959 ◽  
Vol 109 (6) ◽  
pp. 589-600 ◽  
Author(s):  
Hutton D. Slade ◽  
Yoshitami Kimura
Keyword(s):  
Rabbit Antiserum ◽  
M Protein ◽  
Rabbit Serum ◽  
Chemical Fractionation ◽  
Group A Streptococci ◽  
Heterologous Antiserum ◽  
Group A ◽  
Normal Rat ◽  
Group B

Heat-killed cells of Group A streptococci caused death of the adrenalectomized rat. While the adrenalectomized rat readily succumbed to intraperitoneal infection with living cells, death was due primarily to toxicity. The normal rat was highly resistant under either condition. For studies on the toxic materials, the cells of numerous serological types of group A streptococci, and of a Group B and a Group D streptococcus, were extracted with 0.1 N HCl at 100°C. or by sonic oscillation. The extracts, containing macromolecular components, were subjected to chemical fractionation and purification. C substance and M protein of Group A streptococci released from the cell by sonic oscillation were toxic to the adrenalectomized rat in quantities of 1 mg./100 gm. rat. Death usually occurred within 2 hours. On the other hand, C substance and M protein released from the cell with HCl at 100°C. were relatively non-toxic to the adrenalectomized rat. The sonic-extracted C substance of streptococcal Groups B, C, and D was also toxic. The toxic property of the C and M preparations was neutralized in vitro in each case by group and type-specific rabbit antiserum. Heterologous antiserum was without effect. Adrenalectomized rats which received homologous antiserum 18 hours before challenge were also resistant to the toxicity of the C and M preparations. Trypsin destroyed the toxic effect of the M protein preparations and was without effect on the toxicity of the C substance. The R antigen and a nucleoprotein component of Group A streptococci, preparations of protein from Groups B and D streptococci, and coagulase from Staphylococcus aureus were all found to be essentially non-toxicic for the adrenalectomized rat. Large quantities of peptone, crystalline albumin, and rabbit serum were also without effect.

scholarly journals EXAMINATION OF THE L FORMS OF GROUP A STREPTOCOCCI FOR THE GROUP-SPECIFIC POLYSACCHARIDE AND M PROTEIN

1957 ◽  
Vol 105 (2) ◽  
pp. 153-159 ◽  
Author(s):  
John T. Sharp ◽  
W. Hijmans ◽  
L. Dienes
Keyword(s):  
Cell Wall ◽  
M Protein ◽  
Cell Wall Polysaccharide ◽  
Group A Streptococci ◽  
Specific Polysaccharide ◽  
Group A

Two strains of L forms of group A streptococci were examined for group-specific polysaccharide and found to lack this substance. One of these was found to make a substance that had several properties in common with M protein. It is suggested that the absence of the cell wall polysaccharide is responsible for the lack of rigidity of the L form and that the L form of this species closely resembles protoplasts as prepared from other species.

scholarly journals In Vitro Activities of Two Ketolides, HMR 3647 and HMR 3004, against Gram-Positive Bacteria

1999 ◽  
Vol 43 (4) ◽  
pp. 930-936 ◽  
Author(s):  
Kumthorn Malathum ◽  
Teresa M. Coque ◽  
Kavindra V. Singh ◽  
Barbara E. Murray
Keyword(s):  
Dilution Method ◽  
Agar Dilution Method ◽  
Group A Streptococci ◽  
Group B Streptococci ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Streptococci Group B ◽  
Group A ◽  
Group B

ABSTRACT The in vitro activities of two new ketolides, HMR 3647 and HMR 3004, were tested by the agar dilution method against 280 strains of gram-positive bacteria with different antibiotic susceptibility profiles, including Staphylococcus aureus,Enterococcus faecalis, Enterococcus faecium,Streptococcus spp. (group A streptococci, group B streptococci, Streptococcus pneumoniae, and alpha-hemolytic streptococci). Seventeen erythromycin-susceptible (Ems), methicillin-susceptible S. aureus strains were found to have HMR 3647 and HMR 3004 MICs 4- to 16-fold lower than those of erythromycin (MIC at which 50% of isolates were inhibited [MIC50] [HMR 3647 and HMR 3004], 0.03 μg/ml; range, 0.03 to 0.06 μg/ml; MIC50 [erythromycin], 0.25 μg/ml; range, 0.25 to 0.5 μg/ml). All methicillin-resistant S. aureus strains tested were resistant to erythromycin and had HMR 3647 and HMR 3004 MICs of >64 μg/ml. The ketolides were slightly more active against E. faecalis than against E. faecium, and MICs for individual strains varied with erythromycin susceptibility. The MIC50s of HMR 3647 and HMR 3004 against Ems enterococci (MIC ≤ 0.5 μg/ml) and those enterococcal isolates with erythromycin MICs of 1 to 16 μg/ml were 0.015 μg/ml. E. faecalis strains that had erythromycin MICs of 128 to >512 μg/ml showed HMR 3647 MICs in the range of 0.03 to 16 μg/ml and HMR 3004 MICs in the range of 0.03 to 64 μg/ml. In the group of E. faecium strains for which MICs of erythromycin were ≥512 μg/ml, MICs of both ketolides were in the range of 1 to 64 μg/ml, with almost all isolates showing ketolide MICs of ≤16 μg/ml. The ketolides were also more active than erythromycin against group A streptococci, group B streptococci,S. pneumoniae, rhodococci, leuconostocs, pediococci, lactobacilli, and diphtheroids. Time-kill studies showed bactericidal activity against one strain of S. aureus among the four strains tested. The increased activity of ketolides against gram-positive bacteria suggests that further study of these agents for possible efficacy against infections caused by these bacteria is warranted.

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

1952 ◽  
Vol 96 (6) ◽  
pp. 569-580 ◽  
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.

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

1972 ◽  
Vol 18 (1) ◽  
pp. 93-96 ◽  
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.

scholarly journals Putative Novel Surface-Exposed Streptococcus agalactiae Protein Frequently Expressed by the Group B Streptococcus from Zimbabwe

2009 ◽  
Vol 16 (9) ◽  
pp. 1302-1308 ◽  
Author(s):  
Rooyen T. Mavenyengwa ◽  
Johan A. Maeland ◽  
Sylvester R. Moyo
Keyword(s):  
Rabbit Antiserum ◽  
Periodate Oxidation ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protein Antigens ◽  
Group B Streptococci ◽  
Phenotypic Marker ◽  
Whole Cell ◽  
Strain Collection ◽  
Group B

ABSTRACTGroup B streptococci (GBS) express a variety of surface-exposed and strain-variable proteins which function as phenotypic markers and as antigens which are able to induce protective immunity in experimental settings. Among these proteins, the chimeric and immunologically cross-reacting alpha-like proteins are particularly important. Another protein, R3, which has been less well studied, occurred at a frequency of 21.5% in GBS from Zimbabwe and, notably, occurred in serotype V strains at a frequency of 75.9%. Working with rabbit antiserum raised against the R3 reference strain ATCC 49447 (strain 10/84; serotype V/R3) to detect the expression of the R3 protein, we recorded findings which suggested that strain 10/84 expressed a strain-variable protein antigen, in addition to R3. The antigen was detected by various enzyme-linked immunosorbent assay-based tests by using acid extract antigens or GBS whole-cell coats and by whole-cell-based Western blotting. We named the putative novel antigen the Z antigen. The Z antigen was a high-molecular-mass antigen that was susceptible to degradation by pepsin and trypsin but that was resistant tom-periodate oxidation and failed to show immunological cross-reactivity with any of a variety of other GBS protein antigens. The Z antigen was expressed by 33/121 (27.2%) of strains of a Zimbabwean GBS strain collection and by 64.2% and 72.4% of the type Ib and type V strains, respectively, and was occasionally expressed by GBS of other capsular serotypes. Thus, the putative novel GBS protein named Z showed distinct capsular antigen associations and presented as an important phenotypic marker in GBS from Zimbabwe. It may be an important antigen in GBS from larger areas of southern Africa. Its prevalence in GBS from Western countries is not known.

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