CAMP Factor of Group B Streptococci: Production, Assay, and Neutralization by Sera from Immunized Rabbits and Experimentally Infected Cows

Brown, J. David; Farnsworth, R. J.; Wannamaker, Lewis W.; Johnson, Donald W.

doi:10.1128/iai.9.2.377-383.1974

Cited by 32 publications

(8 citation statements)

References 10 publications

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“…2) suggests that two different complexes with different dissociation constants exist under given conditions . Moreover, it should be mentioned that an additional type of protein B/Ig complex is formed by the interaction of protein B with specific antibodies (29), which exhibit true determinant specificities for the protein B. Preliminary experiments indicated that an immunoprecipitate is obtained in agar gel diffusion using purified protein B and antibodies raised against purified protein B in the rabbit.…”

Section: Discussionmentioning

confidence: 99%

Unspecific binding of group B streptococcal cocytolysin (CAMP factor) to immunoglobulins and its possible role in pathogenicity.

Jürgens¹,

Sterzik²,

Fehrenbach³

1987

The Journal of Experimental Medicine

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The protein B of group B streptococci can bind in a nonimmune reaction to Ig of the IgG and IgM classes of various mammalian species (i.e., human, mouse, rabbit, and bovine). Protein B binding involves the Fc parts of both IgG and IgM molecules. Monoclonal or polyclonal IgG or IgM and the IgM-FC5 mu fragment of human myeloma protein combined with the protein B thereby inhibiting protein B-induced hemolysis in the CAMP reaction. The protein B/Ig complex can be dissociated with 1% Triton or guanidine-HCl (6 M). Mice infected intraperitoneally with sublethal doses of group B streptococci (GBS) and that received seven repeated intravenous injections of highly purified protein B during the first 9 h of infection developed fatal septicemia within 24 h with colony counts of up to 10(8) CFU/ml in the blood. Animals treated in the same way with either PBS or trypsinized protein B recovered. The protein B itself was not pathogenic when injected into healthy mice. Tissue sections of liver or spleen from mice infected with a lethal dose of GBS revealed the presence of protein B together with large numbers of cocci when stained by the peroxidase method using specific antibodies raised against purified protein B in the rabbit.

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Section: Discussionmentioning

confidence: 99%

Unspecific binding of group B streptococcal cocytolysin (CAMP factor) to immunoglobulins and its possible role in pathogenicity.

Jürgens¹,

Sterzik²,

Fehrenbach³

1987

The Journal of Experimental Medicine

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“…Assay of CAMP activity. CAMP activity was assayed by a modification of the method of Brown et al (7). Starting with 0.5 ml, volumes of test solution decreasing by about 25% were placed in tubes (12 by 75 mm).…”

Section: Methodsmentioning

confidence: 99%

“…Brown et al (7) showed that sheep erythrocytes preincubated with staphylococcal sphingomyelinase, washed, and then exposed to CAMP protein underwent lysis, whereas sheep erythrocytes exposed to CAMP protein, washed, and then exposed to staphylococcal sphingomyelinase did not lyse. These results indicate that CAMP protein reacts with erythrocytes modified by sphingomyelinase but not with untreated erythrocytes.…”

Section: A B Fig 3 (A)mentioning

confidence: 99%

Nature and mechanism of action of the CAMP protein of group B streptococci

Bernheimer¹,

Linder²,

Avigad³

1979

Infect Immun

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The extracellular product of group B streptococci responsible for the CAMP reaction was purified to near homogeneity. It is a relatively thermostable protein having a molecular weight of 23,500 and an isoelectric pH of 8.3. It was found that the CAMP reaction could be simulated by substituting [14C]glucose-containing liposomes prepared from sphingomyelin, cholesterol, and dicetyl phosphate for sheep erythrocytes. In the belief that the liposome system is a valid model, the mechanism of the CAMP reaction was further investigated by using liposomes in which N-acylsphingosine (ceramide) was substituted for sphingomyelin. In this system disruption of liposomes, as measured by release of trapped [14C]glucose, was effected by CAMP protein alone. As judged from thin-layer chromatography, CAMP protein caused no reduction in the amount of ceramide present in ceramide-containing liposomes, nor were split products demonstrable. However, binding of CAMP protein to ceramide-containing liposomes could be shown. It is inferred that in sheep erythrocytes CAMP protein reacts nonenzymatically with membrane ceramide formed by the prior action of staphylococcal sphingomyelinase and that binding of CAMP protein to ceramide disorganizes the lipid bilayer to an extent that results in cell lysis.

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“…An ancillary factor for the identification of group B streptococci, long utilized in veterinary microbiology, is the CAMP factor, named for the scientists originally describing the phenom- enon (33). The CAMP factor is thought to be a diffusable, heat-stable extracellular protein of group B organisms that enhances rapid hemolysis of sheep erythrocytes by staphylococcal beta-hemolysin (25,47). Classically, the reaction is produced by streaking the staphylococcal strain across the diameter of a sheep blood agar plate, and the streptococcal strains to be assayed perpendicular to the staphylococcal streak.…”

Section: Downloaded Frommentioning

confidence: 99%