Influence of preformed antibody on experimental Streptococcus sanguis endocarditis

Scheld, W. Michael; Thomas, J. H.; Sande, Merle A.

doi:10.1128/iai.25.3.781-785.1979

Cited by 32 publications

(24 citation statements)

References 14 publications

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“…Furthermore, analysis of the titers of anti-NVS surface IgM or IgG in individual rabbits demonstrated no correlation with crossprotection between serotypes II and III. 0 12 24 36 48 60 72 84 Since various investigators have now shown that rabbits TIME (hr) can be preimmunized for protection against endocarditis (1,11,14), the question arises whether antibody or antibody and . Time course analysis of levels of anti-NVS surface complement are sufficient for clearing the organisms by the in the serum of rabbits injected with immune globulin.…”

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confidence: 99%

Analysis of cross-protection between serotypes and passively transferred immune globulin in experimental nutritionally variant streptococcal endocarditis

Rijn

1988

Infect Immun

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Nutritionally variant streptococci (NVS), which account for 5 to 10% of all cases of streptococcal endocarditis, were recently subdivided into three serotypes. In the past, using a rabbit endocarditis model, I demonstrated that by immunization of rabbits with NVS and by challenge with a strain from the homologous serotype a level of 90 to 100% protection was elicited. In the present study, the level of cross-protection between strains from different serotypes was measured. No cross-protection was demonstrated between serotype I and II or III strains. However, significant cross-protection was observed when serotype II and m strains were analyzed in the model. Since high levels of immunoglobulin G were demonstrated against the surface of the NVS after immunization, passive transfer experiments were initiated. Even at comparable levels of surface immunoglobulin G, none of the rabbits given immune globulin were protected against challenge with a dose of live NVS that equaled 20 times the 50% infective dose. Therefore, it appears that components from the immune system, in addition to humoral components, are required for active protection against NVS endocarditis.

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Analysis of cross-protection between serotypes and passively transferred immune globulin in experimental nutritionally variant streptococcal endocarditis

Rijn

1988

Infect Immun

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“…The serological experiments show that streptococcal adhesion to endothelial cells in vitro is effectively blocked by antibodies to AP153 and indicate that immunization with this antigen might offer protection to infective endocarditis by S. gordonii and S. sanguis. Other studies (8,38) have shown that immunization with killed S. sanguis or S. mutans can offer protection against experimental infective endocarditis by these bacteria. The use of GTF vaccines, however, may require inclusion of enzymes from several Streptococcus species to ensure broad protection; for example, Buchan and Jenkinson (3) reported that antibodies raised to GTF of S. gordonii Challis also reacted with S. sanguis FW 227 and S. oralis (ATCC 10557) but not with S. anginosus, S. mutans (NCTC 10449), S. salivarius, or S. sobrinus 6715.…”

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confidence: 99%

Glucosyltransferase mediates adhesion of Streptococcus gordonii to human endothelial cells in vitro

et al. 1994

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Human umbilical vein endothelial cells (HUVEC) were used as an experimental host model to investigate the mechanism(s) of streptococcal adhesion in infective endocarditis. Adhesion activity of Streptococcus gordonii was maximal during the logarithmic phase of growth and was greatly reduced or eliminated by pretreatment of bacteria with heat, formaldehyde, or trypsin. At saturating numbers of streptococci, an average of 81 bacteria were bound per HUVEC. Streptococcal adhesion was inhibited by low-molecular-weight dextran and heparin but not by sucrose, fibronectin, or laminin. Adhesion was also prevented by pretreatment of HUVEC with proteins dissociated from the surface of S. gordonii with 10 mM EDTA or isolated from spent culture medium. Western blot (immunoblot) assays detected a single adhesin protein of 153 kDa (AP153) on HUVEC after incubation with unfractionated extracts of streptococci. The adhesin exhibited glucosyltransferase (GTF) activity when incubated with sucrose and Triton X-100 after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The AP153 was purified by affinity chromatography on dextran beads and shown to have binding activity for HUVEC, GTF activity, an amino acid composition similar to that reported for GTF of S. gordonii, and the ability to inhibit S. gordonii adhesion. Incubation of the streptococci with antibodies to the adhesin inhibited bacterial attachment to HUVEC monolayers. These results indicate that surface-localized GTF mediates adhesion of S. gordonii to HUVEC in vitro and may serve as a mechanism for colonization of the endocardium in infective endocarditis.

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“…These studies demonstrate that qualitative changes do not occur in the cell walls of NVS grown in these two media to the various phases of growth, even though quantitative differences do occur. Therefore, the surface components involved in the pathogenesis of endocarditis are stable to the point that any variation does not affect the ID50-Capsules have been implicated in the adherence process of other streptococci to heart valves (17,19). Since the NVS do not appear to produce a capsule, as determined by Indian ink staining and the absence of a Quellung reaction, other surface component(s) are responsible for the attachment of the bacteria to the heart valve.…”

Section: Discussionmentioning

confidence: 99%

“…During these studies, no common group antigen was found.The rabbit has served as the major animal model for experimental bacterial endocarditis since a reproducible technique was developed by Garrison and Freedman (13). This technique and others derived from it have served to show the role of immunization in the prevention of bacterial endocarditis for streptococci other than NVS (8,19). Since NVS now are serotyped and since a preliminary analysis of their cell surface has been completed (24), we decided to investigate the role of bacterial growth conditions and immunization of rabbits in NVS endocarditis.In this report, we demonstrate that the changes caused by growth of the NVS in different media and to different phases of growth have no effect on the 50% infective dose (ID50) in the experimental rabbit model.…”

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Role of culture conditions and immunization in experimental nutritionally variant streptococcal endocarditis

Rijn¹

1985

Infect Immun

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The nutritionally variant streptococci (NVS) are usually isolated from patients with NVS endocarditis and recently have been serotyped into three groups. In the past, studies on microbial endocarditis have not analyzed the effect of the growth medium or growth phase on the bacteria used to induce the disease in the experimental rabbit model. Therefore, in this study various bacterial growth parameters were examined, including growth in semisynthetic or complex medium to the exponential or stationary phase of growth. The 50% infective dose ranged from 3.7 x 105 to 8.5 x 106 CFU for representative strains from each of the three serotypes growq under these conditions, indicating that there was no significant difference. The role of immunization was also examined in this model using organisms grown to the exponential phase in semisynthetic medium. Rabbits were immunized with heat-killed whole cells, high titers of specific antibody were produced as demonstrated by enzyme-linked immunosorbent assay, and then the rabbits were challenged with 20to 100-fold 50% infective dose of the homologous strain. A total of 90 to 100% of the rabbits were protected from the disease process, as shown by the absence of the organisms from the heart valve 3 days after the challenge. Rabbits immunized with the amphiphile that replaces lipoteichoic acid in these organisms were not protected from challenge, demonstrating that another surface component is responsible for adherence or colonization or both. Finally NVS were incubated with radioiodinated fibronectin, fibrinogen, or laminin to determine whether these molecules aided in the adherence of the organisms to the heart valve. Only minor amounts of these components were bound to NVS as compared with controls. Therefore, NVS bind directly to the damaged heart valve or through an unknown mechanism.The viridans group streptococci are responsible for 50 to 55% of microbial endocarditis. Among these various species, the nutritionally variant streptococci (NVS) recently have been identified as the main organisms associated with culture-negative endocarditis and are responsible for 5 to 10% of all cases of streptococcal endocarditis (18). NVS are characterized by their growth as satellite colonies around colonies of Staphylococcus epidermidis or several other gram-positive or gram-negative bacterial strains (12) and by the presence of a pH-dependent chromophore in their cell wall (5,25). Recently, the NVS has been subdivided into three serotypes by rocket-line immunoelectrophoresis (RIE) and hemagglutination inhibition techniques (26). During these studies, no common group antigen was found.The rabbit has served as the major animal model for experimental bacterial endocarditis since a reproducible technique was developed by Garrison and Freedman (13). This technique and others derived from it have served to show the role of immunization in the prevention of bacterial endocarditis for streptococci other than NVS (8,19). Since NVS now are serotyped and since a preliminary analysis of their cell ...

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Influence of preformed antibody on experimental Streptococcus sanguis endocarditis

Cited by 32 publications

References 14 publications

Analysis of cross-protection between serotypes and passively transferred immune globulin in experimental nutritionally variant streptococcal endocarditis

Analysis of cross-protection between serotypes and passively transferred immune globulin in experimental nutritionally variant streptococcal endocarditis

Glucosyltransferase mediates adhesion of Streptococcus gordonii to human endothelial cells in vitro

Role of culture conditions and immunization in experimental nutritionally variant streptococcal endocarditis

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