Chicken embryo model for type III group B beta-hemolytic streptococcal septicemia

Tieffenberg, J; Vogel, Lawrence C.; Kretschmer, R; Padnos, Donna; Gotoff, Samuel P.

doi:10.1128/iai.19.2.481-485.1978

Cited by 49 publications

(25 citation statements)

References 17 publications

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“…To 100 ~tl of type Ia antiserum, 10 #g of Ib antigen was added and after incubation at 4°C overnight, the sample was centrifuged a n d placed in well [1]. Similarly, the same a m o u n t of Ib antigen was added to type III antiserum a n d placed in well [2] as a control. It can be seen that in the case of the type III serum the Ib antigen remained detectable, whereas it was completely b o u n d by the Ia serum.…”

Section: Characterization Of Iabc Component It Was First Reported Bymentioning

confidence: 99%

Isolation of type-specific polysaccharide antigen from group B type Ib streptococci.

Tai¹,

Gotschlich²,

Lancefield³

1979

The Journal of Experimental Medicine

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Lancefield et al.(1) have clearly demonstrated that the capsular polysaccharides of group B streptococci are antigenic and that the antibodies are protective in mice except with type III, where no mouse-virulent strain is available. However, a chicken embryo model has been established for type III and the antibody found to be specifically protective (2). Recently, emphasis has been centered on the isolation and characterization of the capsular antigens from various types (3-8). However, inasmuch as the capsule is very tightly (probably covalently) bound to the cell wall, a major problem is to find an extraction method that will give satisfactory yield. Conventional HC1 extraction results in partial destruction of the polysaccharide antigens with the loss of the sialic acid determinant (6-8). Current investigations have concentrated on obtaining larger size capsular polysaccharides that are antigenically intact. Neutral buffer extractions have been used successfully to obtain such molecules from type Ia and type III (3, 5). However, the yield is low, which hinders structural studies as well as more extensive clinical and immunological investigations.In this report, we describe the isolation of type Ib polysaccharide from whole cells by digestion with muralytic enzymes prepared from Streptomyces albus. The composition and immunological properties of the purified type Ib antigen are also discussed. Materials and MethodsStreptococcal Strain and Antisera. Group B type Ib (H36B) streptococci and antisera against various types used in this study were from the collection of Dr. R. C. Lancefield of The Rockefeller University. The preparation of antisera was previously described by Lancefield et al.(1).Growth Conditions. Strain H36B (type Ib) was grown in Todd-Hewitt (Difco Laboratories, Detroit, Mich.) broth containing 0.2% yeast extract and 0.2% glucose. 20 ml of overnight culture was inoculated into 4 liters of broth at 37°C. After overnight growth, the cells were harvested by centrifugation and washed twice with 1/x5 M phosphate buffer pH 8.0. Digestion of Type Ib Cells with Lytic Enzymes from Streptornyces albus.The extracellular enzymes of Streptomyces albus were prepared according to the procedure described by McCarty (9).The titer of lytic activity of each enzyme preparation was assayed using group A streptococci (either strain $43, type 6, or strain T28, type 28) as described (9). The lyric activity of an enzyme preparation was considered satisfactory when a 1:10 (vol/vol in 1/15 M phosphate buffer) enzyme dilution caused, within 30 min incubation at 37°C, a 70-80% decrease in turbidity using a cell suspension with an optical density of 0.50 at 600 nm in a 10 X 75-ram tube. The enzyme concentrations of different preparations were equalized based on this assay.

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Section: Characterization Of Iabc Component It Was First Reported Bymentioning

confidence: 99%

Isolation of type-specific polysaccharide antigen from group B type Ib streptococci.

Tai¹,

Gotschlich²,

Lancefield³

1979

The Journal of Experimental Medicine

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“…Studies from several laboratories have es-tablished that antibody is important in GBS immunity (4)(5)(6)(7). Antibody to GBS has been shown to provide protection in several animal models including suckling rats (81, chick embryos (9), and mice (4,10) given lethal challenge of GBS. Furthermore, in vitro studies have demonstrated that efficient phagocytosis and killing of GBS by neutrophils or monocytes requires opsonic antibody (5)(6)(7).…”

mentioning

confidence: 99%

Modified Human Immune Serum Globulin for Intravenous Administration: In Vitro Opsonic Activity and in Vivo Protection Against Group B Streptococcal Disease in Suckling Rats

Fischer¹,

Hunter²,

Wilson³

1982

Acta Paediatrica

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Human immune serum globulin (ISG) preparations were tested in an in vivo suckling rat protection assay and an in vitro opsonophagocytic assay against various types and strains of Group B streptococci (GBS). Standard ISG provided minimal protection in suckling rats against type III GBS sepsis, whereas preparations of ISG modified for intravenous administration (MISG) provided significant protection against all strains of type III, type II and type Ia GBS tested. Although less protection was obtained against type Ia strains, the survival in suckling rats challenged with all types of GBS varied from 73% to 91% with MISG therapy, as compared with 5% to 12% survival in untreated animals. In this in vivo model, MISG was protective even when administered after bacterial challenge, but had to be administered within 5 h of infection. MISG also had high in vitro opsonic activity against GBS types III and II, but was less effective with some type Ia strains. Just as MISG was more protective than ISG in vivo, it also was more opsonic in vitro. A detailed comparison of one lot of MISG with its parent ISG revealed that the modified preparation actually contained less IgG. When equivalent concentrations of affinity-purified IgG from both preparations were tested, the IgG from MISG was significantly more opsonic. Since the affinity purification procedure eliminated the possibility that IgM or substances introduced in the modification process were actually responsible for the enhanced bactericidal activity, it appears that the individual IgG molecules in MISG may be more effective. These studies suggest that MISG which has been modified by reduction and alkylation for intravenous administration may provide a valuable adjunct to chemotherapy in the treatment of GBS disease in the neonate.

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“…Recently, the chicken embryo was reported to be an excellent animal model for studying the virulence of microorganisms pathogenic for humans such as Neisseria gonorrhoeae [8], Neisseria meningitidis [14], Listeria spp. [6] and group B streptococci [32].…”

Section: Discussionmentioning

confidence: 99%

“…Dose-lethality curves were established by i.v. inoculation (usually through the chorioallantoic vein) of 12-day-old chicken embryos with increasing numbers of group A streptococci in 0.1 ml Todd Hewitt broth by the method of Tiefenberg et al [32]. The cfu's were determined by using a counting chamber, whereby 3 cells within a chain were counted as one cfu.…”

Section: Chicken Embryo Assaymentioning

confidence: 99%

Susceptibility of chicken embryos to group A streptococci: Correlation with fibrinogen binding

Schmidt

1993

FEMS Immunology and Medical Microbiology

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One problem in investigating group A streptococcal infections and virulence is the lack of appropriate in vivo models. In this study we introduce the chicken embryo model for determining virulence of Streptococcus pyogenes. We found that M protein positive strains, if administered intravenously, were highly virulent for 12-day-old chicken embryos. The LD50 of the strains tested could be correlated directly with the amount of cell wall exposed M protein, which has been determined by the capacity of streptococci to bind fibrinogen and by the ability of streptococci to survive in fresh normal human blood. The number of colony forming units (cfu) of M+ strains necessary to kill 50% of embryonated eggs was significantly lower (< 10(2) cfu) than for M-variants (> 10(4) cfu). Albumin and/or IgG binding streptococcal cells, which can also take place in proteins of the M protein family which do not bind to fibrinogen, did not show that clear correlation to the virulence in chicken embryos that did fibrinogen binding. Application of anti-streptococcal M protein antisera from chicken and rabbit reduced the lethality of the chicken embryos. In contrast, no correlation was found between lethality of chicken embryos and the in vitro production of erythrogenic toxins by the administered strains. Thus the results indicate that the presence of M-protein with its fibrinogen binding activity on the streptococcal cell surface is necessary for virulence of group A streptococci in the chicken embryo model.

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Chicken embryo model for type III group B beta-hemolytic streptococcal septicemia

Cited by 49 publications

References 17 publications

Isolation of type-specific polysaccharide antigen from group B type Ib streptococci.

Isolation of type-specific polysaccharide antigen from group B type Ib streptococci.

Modified Human Immune Serum Globulin for Intravenous Administration: In Vitro Opsonic Activity and in Vivo Protection Against Group B Streptococcal Disease in Suckling Rats

Susceptibility of chicken embryos to group A streptococci: Correlation with fibrinogen binding

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