View Full Version : What type of bacteria is Borrelia Burgdoferi?

05-17-2016, 05:42 PM
Is one of many bacterial species that belongs spirochete class of the genus Borrelia. The B. burgdorferi, exists mostly in North America and Europe . Borrelia species are considered bacteria of double membrane.

B. burgdorferi is slow-growing with a doubling time of 24 to 48 hours. It is one of the few bacteria that can survive without iron, having replaced all of its iron-sulfur cluster enzymes with enzymes that use manganese, thus avoiding the problem many pathogenic bacteria face in acquiring iron.

B. burgdorferi circulates between ticks and a vertebrate host. B. burgdorferi living in a tick cannot be passed to its offspring. Therefore, ticks must feed on the blood of an infected vertebrate to acquire B. burgdorferi. Infected ticks transmit B. burgdorferi by feeding on another vertebrate to complete the cycle. Ticks, as all you already know, indeed can transmit B. burgdorferi to humans, but humans are very likey to be dead-end hosts, therefore, unlikely to continue the life cycle of the spirochete.

So that's it, some information about burgdoferi without delving in too much details about phylum, class or morphology. It's relevant for everyone to know that the bacteria only can continue its cycle by being transmitted into a vertebrate host, and a tick with B. burgdorferi cannot infect another tick with it. So you can rest assured that a tick bite doesn't always translate into a 100% chance of becoming sick with lyme disease.

05-17-2016, 08:19 PM
I read something many years ago that there was some evolutionary thought that the bacteria and the tick would somehow evolve to the point where the tick no longer recognized humans as potential ´prey´ because as you mentioned the bacteria basically can´t reproduce using humans as the vertebrate because our immune system beats back the bacteria better than most animals and there is low likelihood that a second tick would bite a human who is infected.

Evolutionary history is full of situations where an organism just stops hunting a ´prey´that is not beneficial to it. In other words, there is a strong evolutionary incentive for both the tick and the bacteria to stop infecting humans rather than deer and rabbits.