Question

B. burgdorferi is able to alter its state through environmental cues in order to increase its chance of survival. What causes the tick to change its outer-membrane protein from OspA to OspC?

1) Signals from the tick's blood meal
2) Signals from the host's immune response
3) Signals from the tick's midgut adhesion
4) Signals from the bacteria's antigen presentation

Answer 1

The tick prompts a change from OspA to OspC in response to its midgut adhesion after a blood meal, which is a mechanism for B. burgdorferi to evade the immune system through antigenic variation.Hence, the correct answer is option 3.

Step-by-step explanation:

The tick changes its outer-membrane protein from OspA to OspC in response to signals from the tick's midgut adhesion after taking a blood meal from a host. This change is part of a mechanism known as antigenic variation, which helps the bacterium Borrelia burgdorferi, the causative agent of Lyme disease, evade the host's immune system. Despite its complex life cycle involving different hosts, including ticks, deer, and mice, B. burgdorferi is able to alter its surface proteins, such as VlsE, through genetic recombination, which allows it to persist and cause chronic disease in humans. Infection occurs through vector transmission, where the tick acts as the vector, much like mosquitoes transmit the pathogen that causes malaria.