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Updated: Jun 22, 2026
Total Protein Extraction and 2-D Gel Electrophoresis Methods for Burkholderia Species
Published on: October 15, 2013
Comparative analysis of extracellular enzymes and virulence exhibited by Burkholderia pseudomallei from different
Kumutha Malar Vellasamy1, Chenthamarakshan Vasu, Savithri Devi Puthucheary
1Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia.
Abstract:
To evaluate the potential role of extracellular proteins in the pathogenicity and virulence of Burkholderia pseudomallei, the activities of several enzymes in the culture filtrates of nine clinical and six environmental isolates were investigated in vitro and in vivo in ICR strain of mice. The production of protease, phosphatase, phospholipase C, superoxide dismutase, catalase and peroxidase were detected in the culture filtrates of all the 15 isolates at different time points of growth 4-24h. Over time, activity of each enzyme at each time point varied. Profile of secretion was similar among the 15 isolates irrespective of source, that is clinical or environmental. Catalase, phosphatase and phospholipase C were found to be increased in 60-100% of the isolates post-passage in mice. In vivo inoculation studies in ICR mice demonstrated a wide difference in their ability to cause bacteraemia, splenic or external abscesses and mortality rate ranged from few days to several weeks.
Insights
Extracellular enzymes like catalase and phospholipase C are crucial for Burkholderia pseudomallei virulence. Enzyme activity varied but showed similar secretion profiles across clinical and environmental isolates.
Area of Science:
- Microbiology
- Pathogen Virulence
- Bacterial Pathogenesis
Background:
- Burkholderia pseudomallei is an opportunistic pathogen responsible for melioidosis.
- Extracellular proteins play a significant role in bacterial pathogenicity and virulence.
- Understanding these factors is crucial for developing effective treatments and prevention strategies.
Purpose of the Study:
- To investigate the role of extracellular enzymes in the pathogenicity and virulence of Burkholderia pseudomallei.
- To compare enzyme activities between clinical and environmental isolates.
- To assess the impact of in vivo passage on enzyme production.
Main Methods:
- Enzyme activities (protease, phosphatase, phospholipase C, superoxide dismutase, catalase, peroxidase) were measured in vitro in culture filtrates of 15 Burkholderia pseudomallei isolates (9 clinical, 6 environmental).
- Enzyme production was monitored at different growth time points (4-24h).
- In vivo studies involved inoculating ICR mice to assess pathogenicity, including bacteraemia, abscess formation, and mortality.
Main Results:
- All 15 isolates produced protease, phosphatase, phospholipase C, superoxide dismutase, catalase, and peroxidase.
- Enzyme activity varied over time and between isolates, but secretion profiles were similar across clinical and environmental sources.
- Catalase, phosphatase, and phospholipase C activities increased in 60-100% of isolates after passage in mice.
- In vivo studies revealed significant differences in the ability of isolates to cause bacteraemia, splenic/external abscesses, and mortality.
Conclusions:
- Extracellular enzymes are secreted by all Burkholderia pseudomallei isolates, regardless of origin.
- Certain enzymes, notably catalase, phosphatase, and phospholipase C, are upregulated post-in vivo passage, suggesting their importance in virulence.
- The diverse pathogenicity observed in mice highlights the complex interplay between bacterial factors and host response.
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