Promotion of fibronectin independent invasion by C5a peptidase into epithelial cells in group A Streptococcus

Sai Sudha Purushothaman, Hae Sun Park, P. Patrick Cleary

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Background & objectives: Group A Streptococcus, causative agent of several clinical manifestations codes for multiple protein invasins which help the bacterium to enter non-phagocytic cells. C5a peptidase (SCPA) is a surface protein conserved among different serotypes of M1 strain. The present study was taken up to study SCPA promoted fibronectin independent entry of GAS into epithelial cells. Methods: An isogenic 90226 emm1ΔAB (M1-) mutant was constructed with thermosensitive pGhost vector. This isogenic M1- mutant expressed SCPA on the surface as determined by Western blotting and immunofluorescence. Results: On preincubation with anti-SCPA serum, the isogenic M1- strain exhibited 54 per cent decreased invasion as compared to the bacteria incubated with control serum. Also, purified recombinant SCPA proteins blocked internalization of M1- streptococci into HEp-2 cells. The M1- strain invaded at the same efficiency in the presence or absence of fibronectin. Interpretation & conclusion: These results suggested that SCPA acted as a potential invasin of group A streptococcus and promoted invasion independent of fibronectin.

Original languageEnglish (US)
Pages (from-to)44-47
Number of pages4
JournalIndian Journal of Medical Research, Supplement
Issue numberMAY
StatePublished - 2004
Externally publishedYes


  • C5a peptidase
  • Fibronectin
  • Group A streptococcus
  • Invasion
  • M1 strain

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)


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