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Updated: Aug 14, 2026

Methods for Rapid Transfer and Localization of Lyme Disease Pathogens Within the Tick Gut
Published on: February 14, 2011
[Intracellular development of Rickettsia]
Abstract:
Microcinematography, cytological and cytochemical studies revealed new features of D. sibericus, D. murinus, and R. tsutsugamushi biology, mainly a very active movement in the cell. In contrast to D. sibericus, development of D. murinus and R. tsutsugamushi in cells is characterized by severe irritation of the infected cells early in the infection, a greater speed of movement of rickettsiae and their active release from the affected cells, as well as the development of necrobiotic changes in the latter. The mitotic activity of the cells increased early in cultures infected with Cox. burneti, R. prowazeki, D. sibericus, and T. tsutsugamushi. Subsequently, cell nuclei shrink and different cytotic changes develop in various rickettsia. Studies on the metabolism of the affected cells revealed activation of nucleic metabolism and redox enzymes associated with mitochondria in the course of the first 3 days followed by a low activity in 5 postinfection days. The lysosomal apparatus of the cells underwent drastic changes and the activity of acid phosphatase increased markedly with further elevation in the permeability of lysosomal membranes.
Insights
Rickettsiae species exhibit active intracellular movement and cause significant cellular damage, including necrobiosis and altered metabolism. Early infection stages show increased cell division, followed by nuclear changes and lysosomal disruption.
Area of Science:
- Cell biology
- Microbiology
- Pathogenesis
Context:
- Rickettsiae are obligate intracellular bacteria known to cause various diseases.
- Understanding their interaction with host cells is crucial for developing treatments.
Purpose:
- To investigate the cellular and subcellular effects of Rickettsia species (D. sibericus, D. murinus, R. tsutsugamushi) and Coxiella burnetii on host cells.
- To elucidate the dynamic intracellular behavior and host cell responses during infection.
Summary:
- Microcinematography and cytological studies revealed distinct intracellular behaviors of Rickettsia species.
- D. murinus and R. tsutsugamushi induce early cell irritation, rapid movement, and active release, unlike D. sibericus.
- Infected cells exhibit increased mitotic activity, followed by nuclear shrinkage and cytotic changes.
- Metabolic studies show initial activation of nucleic metabolism and mitochondrial enzymes, declining by day 5.
- Significant alterations in the lysosomal apparatus, including increased acid phosphatase activity and membrane permeability, were observed.
Impact:
- Provides novel insights into the pathogenesis of rickettsial infections at the cellular level.
- Highlights differences in host-pathogen interactions among Rickettsia species.
- Suggests potential targets for therapeutic intervention by understanding metabolic and lysosomal changes.
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