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Phenotypic Analysis of Rodent Malaria Parasite Asexual and Sexual Blood Stages and Mosquito Stages
Published on: May 30, 2019
STUDIES ON MALARIAL PARASITES : VIII. FACTORS AFFECTING THE GROWTH OF PLASMODIUM KNOWLESI IN VITRO
C B Anfinsen1, Q M Geiman, R W McKee
1Department of Biological Chemistry, Harvard Medical School, and the Department of Comparative Pathology and Tropical Medicine, Harvard School of Public Health and Harvard Medical School, Boston.
The Journal of Experimental Medicine
|October 30, 2009
Summary
Researchers developed a synthetic medium for Plasmodium knowlesi asexual cycle growth. Supplementation with whole blood or plasma enabled subculturing, and specific gas compositions and nutrient needs were identified for parasite cultivation.
Area of Science:
- Malariology
- Parasitology
- Cell Biology
Background:
- Plasmodium knowlesi is a significant cause of malaria.
- Understanding Plasmodium knowlesi in vitro culture is crucial for developing new treatments and vaccines.
- Previous culture methods were limited in supporting long-term parasite growth and multiplication.
Purpose of the Study:
- To develop a synthetic nutrient medium supporting the asexual erythrocytic cycle of Plasmodium knowlesi.
- To identify optimal conditions for in vitro cultivation, including gas composition and nutrient requirements.
- To overcome limitations in current culture methods for Plasmodium knowlesi.
Main Methods:
- Preparation and sterilization of a synthetic nutrient medium.
- In vitro cultivation of Plasmodium knowlesi erythrocytic forms.
- Addition of whole blood or plasma for subculturing.
- Gas phase manipulation (oxygen levels) and nutrient supplementation experiments.
- Infection of monkeys with cultured parasites to assess infectivity.
Main Results:
- A synthetic medium supported normal growth during a 24-hour asexual cycle.
- Successful successive subcultures were achieved with whole blood or plasma addition.
- Injected cultured parasites successfully induced malaria in monkeys.
- Optimal oxygen concentration for in vitro growth was determined (approximating alveolar air or lower).
- Parasite growth was enhanced in normal monkey plasma, and heating parasitized plasma removed inhibitory effects.
- Nutritional requirements for glucose and p-aminobenzoic acid were demonstrated.
- Interference from red blood cells and plasma nutrients was identified as a challenge for further nutritional studies.
Conclusions:
- A synthetic medium can support the in vitro asexual erythrocytic cycle of Plasmodium knowlesi.
- Optimized gas composition and nutrient supplementation are critical for successful cultivation.
- Further research into parasite nutritional requirements is needed, with strategies to minimize host cell interference.
- Successful cultivation provides a platform for studying Plasmodium knowlesi biology and developing interventions.
Keywords:
MALARIA/plasmodium
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