Related Experiment Video
Updated: Feb 3, 2026
Detecting the Lyme Disease Spirochete, Borrelia Burgdorferi, in Ticks Using Nested PCR
Published on: February 4, 2018
Competition between strains of Borrelia afzelii inside the rodent host and the tick vector
Dolores Genné1, Anouk Sarr2, Andrea Gomez-Chamorro2
1Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland dolores.genne@unine.ch.
Abstract:
Multiple-strain pathogens often establish mixed infections inside the host that result in competition between strains. In vector-borne pathogens, the competitive ability of strains must be measured in both the vertebrate host and the arthropod vector to understand the outcome of competition. Such studies could reveal the existence of trade-offs in competitive ability between different host types. We used the tick-borne bacterium Borrelia afzelii to test for competition between strains in the rodent host and the tick vector, and to test for a trade-off in competitive ability between these two host types. Mice were infected via tick bite with either one or two strains, and these mice were subsequently used to create ticks with single or mixed infections. Competition in the rodent host reduced strain-specific host-to-tick transmission and competition in the tick vector reduced the abundance of both strains. The strain that was competitively superior in host-to-tick transmission was competitively inferior with respect to bacterial abundance in the tick. This study suggests that in multiple-strain vector-borne pathogens there are trade-offs in competitive ability between the vertebrate host and the arthropod vector. Such trade-offs could play an important role in the coexistence of pathogen strains.
Insights
Competition between multiple pathogen strains in hosts and vectors can lead to trade-offs. This study on Borrelia afzelii found that competitive advantages in one host type (rodent) conferred disadvantages in another (tick), impacting pathogen coexistence.
Area of Science:
- Microbiology
- Ecology
- Epidemiology
Background:
- Multiple pathogen strains can co-infect a host, leading to inter-strain competition.
- Understanding competition in both host and vector is crucial for vector-borne pathogens.
- Competition dynamics can influence pathogen evolution and disease transmission.
Purpose of the Study:
- To investigate competition between Borrelia afzelii strains in rodent hosts and tick vectors.
- To determine if competitive trade-offs exist between these host types.
- To understand the implications of these trade-offs for pathogen strain coexistence.
Main Methods:
- Mice were infected with single or mixed strains of Borrelia afzelii via tick bite.
- Infected mice were used to generate ticks with single or mixed infections.
- Competitive ability was assessed by measuring strain-specific transmission and abundance in both hosts.
Main Results:
- Competition in the rodent host reduced the transmission efficiency of individual strains to ticks.
- Competition within the tick vector decreased the abundance of both co-infecting strains.
- A strain competitively superior in host-to-tick transmission was inferior in tick abundance, indicating a trade-off.
Conclusions:
- Borrelia afzelii exhibits trade-offs in competitive ability between rodent hosts and tick vectors.
- These trade-offs likely play a significant role in maintaining the diversity of pathogen strains.
- Findings have implications for understanding the population dynamics of vector-borne diseases.
Related Concept Videos
02:34Competition
01:30Vectors
01:19Thermal Strain
01:20Shearing Strain
01:27Measurements of Strain
01:13Strain Energy
Consider a rod that is fixed at one end and subjected to an axial force at the free end. This axial force induces stress within the rod, leading to its elongation. As the axial force increases, so does the elongation of the rod, illustrating a direct relationship between the force applied and the resulting...