Related Experiment Videos
Electron microscopic studies on the in vitro proliferation of spotted fever group rickettsia isolated in Japan
K Amano1, H Hatakeyama, Y Sasaki
1Central Research Laboratory, Akita University, School of Medicine.
Abstract:
Rickettsia was isolated from a patient with Japanese spotted fever, and its proliferation in cultured green monkey kidney cells was observed by electron microscopy. In the course of this study, we observed fusion of infected cells to uninfected cells which may be a way of spreading the rickettsiae from a cell to another. On the other hand, whirlpool-like, multilayer membranous structures, similar to the mesosomes of gram-negative bacteria, were sometimes seen in the rickettsial cells. The other profiles common to the other rickettsiae in spotted fever group were observed, such as the electron-lucent halo zone around the rickettsiae, and external fibrous materials on their surface, but intranuclear multiplication was rarely observed.
Insights
Japanese spotted fever rickettsiae were observed in cultured cells, revealing cell fusion as a potential spread mechanism. Unusual membranous structures were also noted within the bacteria.
Area of Science:
- Microbiology
- Cell Biology
- Infectious Diseases
Background:
- Japanese spotted fever is a significant tick-borne illness.
- Rickettsia species are the causative agents of spotted fevers.
- Understanding Rickettsia pathogenesis is crucial for disease control.
Purpose of the Study:
- To investigate the cellular behavior and ultrastructure of Rickettsia during infection.
- To identify potential mechanisms of Rickettsia spread within host cells.
Main Methods:
- Isolation of Rickettsia from a patient with Japanese spotted fever.
- Cultivation of Rickettsia in green monkey kidney cells.
- Observation of infected cells using electron microscopy.
Main Results:
- Rickettsia proliferation was observed in cultured cells.
- Cell fusion between infected and uninfected cells was documented, suggesting a potential spread mechanism.
- Unique whirlpool-like, multilayer membranous structures were observed within rickettsial cells.
- Characteristic features like electron-lucent halos and external fibrous materials were present.
- Intranuclear multiplication of Rickettsia was rarely observed.
Conclusions:
- Cell fusion may represent an important mode of Rickettsia dissemination.
- The observed ultrastructural features provide insights into Rickettsia biology.
- Further research is needed to fully elucidate Rickettsia-host cell interactions.