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Published on: January 3, 2020
Cytotoxic activity of Serratia marcescens clinical isolates
Sylwia Krzymińska1, Marta Raczkowska, Adam Kaznowski
1Department of Microbiology, Faculty of Biology, A. Mickiewicz University, Poznań, Poland.
Abstract:
Twenty Serratia marcescens isolates from clinical specimens were examined for their cytotoxic activity on four cell lines (HEp-2, Vero, CHO, J774). Most of the isolates were found to be cytotoxic to CHO (70%), Vero (75%) and HEp-2 cells (90%). CHO cells were the most sensitive to cell-free supernatants, followed by HEp-2 and Vero cells. Two strains produced cytotonic toxins which caused elongation of CHO cells. Moreover, twelve isolates (60%) revealed cytotoxic potential to macrophage cell line J774. The results indicate that these bacteria may destroy phagocytes and epithelial cells, which may lead to spread within the host.
Insights
Most clinical Serratia marcescens isolates exhibit cytotoxic effects on various cell lines, including epithelial and macrophage cells. This bacterial cytotoxicity may contribute to host tissue damage and infection spread.
Area of Science:
- Microbiology
- Cell Biology
- Infectious Diseases
Background:
- Serratia marcescens is an opportunistic pathogen frequently isolated from clinical specimens.
- Understanding the cytotoxic potential of S. marcescens is crucial for assessing its pathogenicity.
- Previous studies have indicated varying degrees of virulence among S. marcescens strains.
Purpose of the Study:
- To investigate the cytotoxic and cytotonic activities of clinical Serratia marcescens isolates.
- To determine the sensitivity of different cell lines to S. marcescens-derived toxins.
- To evaluate the potential of these bacteria to damage host cells, including phagocytes and epithelial cells.
Main Methods:
- Twenty clinical isolates of Serratia marcescens were cultured.
- Cell-free supernatants were applied to HEp-2, Vero, CHO, and J774 (macrophage) cell lines.
- Cytotoxicity and cytotonic effects (cell elongation) were assessed.
Main Results:
- A high percentage of isolates showed cytotoxicity against HEp-2 (90%), Vero (75%), and CHO (70%) cells.
- CHO cells exhibited the highest sensitivity to the bacterial supernatants, followed by HEp-2 and Vero cells.
- Two strains produced cytotonic toxins, causing CHO cell elongation, and 60% of isolates were cytotoxic to J774 macrophages.
Conclusions:
- Clinical Serratia marcescens isolates possess significant cytotoxic potential against various host cell types.
- The observed cytotoxicity towards epithelial and phagocytic cells suggests a mechanism for host tissue invasion and immune evasion.
- These findings highlight the potential of S. marcescens to cause significant cellular damage, contributing to disease pathogenesis.
