Virulent human strains of group G streptococci express a C5a peptidase enzyme similar to that produced by group A streptococci

Cleary, P. Patrick; Peterson, Julie A.; Chen, C; Nelson, Christine E.

doi:10.1128/iai.59.7.2305-2310.1991

Cited by 64 publications

(23 citation statements)

References 20 publications

(45 reference statements)

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“…We previously showed that SCPA can retard recruitment of PMNLs in response to GAS injected into the mouse peritoneum (10). Discovery of C5a peptidase-associated human isolates of two additional species of streptococci, groups B and G (6,9), further supports our contention that specific destruction of C5a is an important virulence mechanism. Hill et al invoked C5a-ase activity as a reason for the feeble influx of phagocytic cells into GBS-infected tissues of human neonates (9).…”

Section: Gassupporting

confidence: 75%

Similarity between the group B and A streptococcal C5a peptidase genes

et al. 1992

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Group B streptococci (GBS) and group A streptococci (GAS) are known to have surface-associated peptidase activity which specifically cleaves C5a (C5a-ase), the primary chemotaxin for polymorphonuclear leukocytes. Amplification products were obtained from GBS genomic DNA template by using the polymerase chain reaction and primers corresponding to the C5a peptidase gene of GAS (scpA12). A restriction map of the GBS full-length amplified gene (scpB) was developed. The scpB restriction map was found to be highly similar to that of the analogous gene in GAS. A 50-bp deletion was located near the 5' end of scpB in a region where repeat sequences are found in scpA12. Hybridization experiments confirmed that other serotypes of GBS also carry an scpB-like gene. These results show that GBS contain a gene, scpB, which is very similar to that harbored by M12 GAS. The probability that scpB encodes the C5a-ase protein is discussed. * Corresponding author. an scpA12-like gene (scpB) in GBS DNA. The results show that the GBS gene is strikingly similar to that of GAS.

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Section: Gassupporting

confidence: 75%

Similarity between the group B and A streptococcal C5a peptidase genes

et al. 1992

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“…The C5a peptidase has been investigated as a vaccine candidate due to its widespread conservation throughout GAS (385). Genes nearly identical to scpA have also been found in both group B and G streptococci, although the expression of scpA in the group G streptococci appears to be restricted to the specific strains that are capable of infecting humans (119,123,124).…”

Section: Streptococcus Pyogenes (Group a Streptococci)mentioning

confidence: 99%

Surface Proteins of Gram-Positive Bacteria and Mechanisms of Their Targeting to the Cell Wall Envelope

Navarre

Schneewind

1999

Microbiol Mol Biol Rev

1,186

601

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SUMMARY The cell wall envelope of gram-positive bacteria is a macromolecular, exoskeletal organelle that is assembled and turned over at designated sites. The cell wall also functions as a surface organelle that allows gram-positive pathogens to interact with their environment, in particular the tissues of the infected host. All of these functions require that surface proteins and enzymes be properly targeted to the cell wall envelope. Two basic mechanisms, cell wall sorting and targeting, have been identified. Cell well sorting is the covalent attachment of surface proteins to the peptidoglycan via a C-terminal sorting signal that contains a consensus LPXTG sequence. More than 100 proteins that possess cell wall-sorting signals, including the M proteins of Streptococcus pyogenes, protein A of Staphylococcus aureus, and several internalins of Listeria monocytogenes, have been identified. Cell wall targeting involves the noncovalent attachment of proteins to the cell surface via specialized binding domains. Several of these wall-binding domains appear to interact with secondary wall polymers that are associated with the peptidoglycan, for example teichoic acids and polysaccharides. Proteins that are targeted to the cell surface include muralytic enzymes such as autolysins, lysostaphin, and phage lytic enzymes. Other examples for targeted proteins are the surface S-layer proteins of bacilli and clostridia, as well as virulence factors required for the pathogenesis of L. monocytogenes (internalin B) and Streptococcus pneumoniae (PspA) infections. In this review we describe the mechanisms for both sorting and targeting of proteins to the envelope of gram-positive bacteria and review the functions of known surface proteins.

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“…C5a is cleaved between the His-67 and Lys-68 residues of C5a, a region of the chemotaxin which binds to receptors located on the surface of polymorphonuclear leukocytes (PMNLs) (13,35). A similar peptidase was also shown to be expressed by human isolates of group B (11,18), C (unpublished data), and G (12) streptococci.…”

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confidence: 90%

C5a peptidase alters clearance and trafficking of group A streptococci by infected mice

et al. 1996

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Group A streptococcal C5a peptidase (SCPA) specifically cleaves the human serum chemotaxin C5a at the polymorphonuclear leukocyte (PMNL) binding site. This study tested the proposal that SCPA contributes to virulence by retarding the influx of inflammatory cells and clearance of streptococci during the first few hours after infection. To investigate the specific contribution of SCPA to the virulence of group A streptococci, scpA insertion and deletion mutants were created by directed plasmid insertion into scpA and gene replacement. The precise locations of insertion and deletion mutations were confirmed by PCR and DNA sequence analysis. The impact of mutation on virulence was investigated with a mouse air sac model of inflammation. Experiments evaluated clearance of streptococci from the air sac within 4 h after infection. SCPA ؊ streptococci were cleared more efficiently than wild-type bacteria. Localization of streptococci in lymph nodes and spleens of infected mice revealed a significant difference between mutant and wild-type streptococci. PMNLs and other granulocytes that infiltrated the air sac were quantitated by single-color flow cytometry. The total cellular infiltrate was greater and PMNLs dominated the granulocytic infiltrates of air sacs inoculated with SCPA ؊ mutant bacteria. The data obtained are consistent with the possibility that SCPA ؊ streptococci are initially cleared from the site of infection primarily by PMNLs. Moreover, mutant and wild-type streptococci followed different paths of dissemination. SCPA ؊ bacteria were transported to lymph nodes, whereas wild-type streptococci avoided transport to the lymph nodes and rapidly spread to the spleen.

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Virulent human strains of group G streptococci express a C5a peptidase enzyme similar to that produced by group A streptococci

Cited by 64 publications

References 20 publications

Similarity between the group B and A streptococcal C5a peptidase genes

Similarity between the group B and A streptococcal C5a peptidase genes

Surface Proteins of Gram-Positive Bacteria and Mechanisms of Their Targeting to the Cell Wall Envelope

C5a peptidase alters clearance and trafficking of group A streptococci by infected mice

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