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Methods for Rapid Transfer and Localization of Lyme Disease Pathogens Within the Tick Gut
Published on: February 14, 2011
An efficient microinjection method to generate human anaplasmosis agent Anaplasma phagocytophilum-infected ticks
Vikas Taank1, Ellango Ramasamy1, Hameeda Sultana1,2
1Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA.
Abstract:
Ticks are important vectors that transmit several pathogens including human anaplasmosis agent, Anaplasma phagocytophilum. This bacterium is an obligate intracellular rickettsial pathogen. An infected reservoir animal host is often required for maintenance of this bacterial colony and as a source for blood to perform needle inoculations in naïve animals for tick feeding studies. In this study, we report an efficient microinjection method to generate A. phagocytophilum-infected ticks in laboratory conditions. The dense-core (DC) form of A. phagocytophilum was isolated from in vitro cultures and injected into the anal pore of unfed uninfected Ixodes scapularis nymphal ticks. These ticks successfully transmitted A. phagocytophilum to the murine host. The bacterial loads were detected in murine blood, spleen, and liver tissues. In addition, larval ticks successfully acquired A. phagocytophilum from mice that were previously infected by feeding with DC-microinjected nymphal ticks. Transstadial transmission of A. phagocytophilum from larvae to nymphal stage was also evident in these ticks. Taken together, our study provides a timely, rapid, and an efficient method not only to generate A. phagocytophilum-infected ticks but also provides a tool to understand acquisition and transmission dynamics of this bacterium and perhaps other rickettsial pathogens from medically important vectors.
Insights
Researchers developed an efficient microinjection technique to create Anaplasma phagocytophilum-infected ticks in the lab. This method aids in studying the transmission dynamics of this important tick-borne pathogen.
Area of Science:
- Vector-borne diseases
- Microbiology
- Entomology
Background:
- Anaplasma phagocytophilum is a significant tick-borne pathogen causing human anaplasmosis.
- Maintaining infected tick colonies for research often relies on animal hosts and needle inoculation, which can be inefficient.
- Efficient methods are needed to generate infected ticks for studying pathogen transmission dynamics.
Purpose of the Study:
- To develop and validate an efficient laboratory method for generating Anaplasma phagocytophilum-infected Ixodes scapularis ticks.
- To assess the capability of microinjected ticks to transmit A. phagocytophilum to a mammalian host.
- To investigate the acquisition and transstadial transmission of A. phagocytophilum in ticks originating from infected hosts.
Main Methods:
- Isolation of the dense-core (DC) form of A. phagocytophilum from in vitro cultures.
- Microinjection of DC-form A. phagocytophilum into the anal pore of unfed Ixodes scapularis nymphs.
- Transmission studies involving infected ticks feeding on murine hosts.
- Detection of bacterial loads in host tissues and subsequent acquisition by larval ticks.
Main Results:
- Microinjected ticks successfully transmitted A. phagocytophilum to mice, with detectable bacterial loads in blood, spleen, and liver.
- Larval ticks acquired A. phagocytophilum from infected mice.
- Transstadial transmission of A. phagocytophilum from the larval to nymphal stage was confirmed.
Conclusions:
- The study presents a rapid and efficient microinjection method for generating A. phagocytophilum-infected ticks.
- This method serves as a valuable tool for understanding the acquisition and transmission dynamics of A. phagocytophilum and potentially other rickettsial pathogens.
- The findings facilitate research on tick-borne diseases and vector control strategies.
