Apoptosis of human keratinocytes after bacterial invasion

FEMS Immunol Med Microbiol. 2000 Mar;27(3):235-40. doi: 10.1111/j.1574-695X.2000.tb01435.x.

Abstract

In this study, we examined the invasive capacity of Staphylococcus aureus and Salmonella typhi in human keratinocytes and monitored the number of viable intracellular bacteria at different post-infection times. The strains tested entered keratinocytes; both S. typhi and S. aureus were internalized within 30 min to 2 h after infection. No intracellular multiplication was observed, but S. typhi and S. aureus remained viable 72 h after infection. We also demonstrated that keratinocyte death following S. typhi and S. aureus invasion occurs by apoptosis as shown by DNA fragmentation. After 24 h of infection with S. typhi, the number of cells undergoing apoptosis were higher compared to infection with S. aureus. For prolonged infection times (48 h, 72 h) with both bacteria, there was no significant change in the number of cells undergoing apoptosis. The results demonstrated that viable intracellular S. typhi and S. aureus induced apoptosis in keratinocyte cells.

MeSH terms

  • Apoptosis*
  • Cells, Cultured
  • DNA Fragmentation
  • Humans
  • Keratinocytes / cytology
  • Keratinocytes / microbiology*
  • Salmonella typhi / growth & development
  • Salmonella typhi / pathogenicity*
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / growth & development
  • Staphylococcus aureus / pathogenicity*
  • Typhoid Fever / microbiology