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Cytotoxin production in phytopathogenic and entomopathogenic Serratia marcescens

M M Escobar1, G V Carbonell, L O Beriam

  • 1Departamento de Microbiología e Imunologia, Universidade Estadual de Campinas, SP, Brasil.

Revista Latinoamericana De Microbiologia
|October 26, 2006
PubMed

Insights

Entomopathogenic and phytopathogenic Serratia marcescens strains produce a cytotoxin toxic to mammalian cells. This finding is crucial for understanding their role as biological control agents.

Area of Science:

  • Microbiology
  • Cell Biology
  • Toxicology

Background:

  • Serratia marcescens is known for its entomopathogenic and phytopathogenic capabilities.
  • The bacterium produces various toxins, but their specific effects on mammalian cell lines require further investigation.

Purpose of the Study:

  • To investigate the cytotoxic effects of entomopathogenic and phytopathogenic Serratia marcescens on mammalian cell lines.
  • To determine the nature of the cytotoxic substance and its implications for biological control applications.

Main Methods:

  • Culture filtrates from S. marcescens strains were applied to CHO, Vero, and HEp-2 cell lines.
  • Morphological changes and cell viability were assessed over 24 hours.
  • Toxicity was evaluated on onion and lettuce plantlets.
  • Neutralization assays using specific antiserum were performed.

Main Results:

  • Culture filtrates induced significant cytotoxic effects, including cell rounding, detachment, and death, within 24 hours.
  • The cytotoxic effect was neutralized by specific antiserum, indicating antigenic similarity among cytotoxins.
  • Culture supernatants did not harm plants, but bacterial suspensions caused disease symptoms in onion and lettuce.
  • Phytopathogenic and entomopathogenic S. marcescens strains produce a cytotoxin similar to those from clinical isolates.

Conclusions:

  • Serratia marcescens strains, whether entomopathogenic or phytopathogenic, can produce cytotoxins harmful to mammalian cell lines.
  • The cytotoxin exhibits antigenic similarity across different strains.
  • These findings have significant implications for the use of S. marcescens as a biological control agent, highlighting potential risks to non-target organisms.

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