Lyme disease is a bacterial infection contracted when a person gets bitten by a tick that is infected with the borrelia burgdorferi bacteria. When a person gets Lyme disease, they can experience a vast number of different symptoms, many of which are non-specific and can mimic various types of other health conditions – leading to the disease being referred to as the “great imitator.”
Medical researchers have been tirelessly working to understand the borrelia burgdorferi bacteria further so that they can develop a better approach to Lyme disease treatment. Currently, the only treatment is antibiotics – and in 20% of cases, these don’t work, leaving people to go on to develop chronic Lyme disease.
Since chronic Lyme can cause debilitating symptoms, and the spread of the infection continues to rise worldwide, understanding the structure of Lyme bacteria as well as how it manages to evade detection within the body is vital.
What is the structure of borrelia burgdorferi?
The borrelia burgdorferi bacteria belongs to the spirochaetaceae family of bacteria, more simply known as spirochetes. This family gets its name from the unique spiral shape of the bacteria. Borrelia burgdorferi, specifically, is a helical-shaped spirochete that has both an inner and outer membrane wall.
The cell wall is flexible in nature, and within the membranes of the cell is protoplasm that is long and shaped like a cylinder. The cell itself can range in size from 10 to 25 micrometers in length, but is typically only 1 micrometer wide.
While bacteria in the spirochete family typically take on similar shapes, the borrelia burgdorferi bacteria is unique in the sense that its cell’s flagella are located not on the back side of the cell, but between the outer and inner cell membranes in the periplasm. This specialized location is what helps the cell travel through materials and thick fluids.
What is LPS?
LPS is the abbreviated form of lipopolysaccharides, which are a type of large molecule. These molecules contain both a polysaccharide as well as a lipid, which is composed of O-antigen. They are considered to be one of the most researched and studied molecules that can be found on the surface of bacteria cells – most specifically, gram negative bacteria cells.
This molecule has important jobs to do when it comes to cell life. For a cell to sustain itself, it needs be able to maintain its structural integrity. LPS is designed to help create a porous or spongy type of barrier on the surface of the cell so that it can keep the structure of the outer membrane strong enough to survive.
The spongy barrier that LPS helps to create for the cells is also important when it comes to evading other antimicrobial compounds, because it acts as a protective layer, stopping small hydrophobic molecules from getting through. When the bacteria gets into a host, the LPS also helps to regulate how the immune system of the host responds to its presence, which could be part of the reason why the borrelia burgdorferi is so hard to get rid of once it enters humans.
Do spirochetes have LPS?
In short, yes, spirochetes do have LPS. The bacteria that falls into this category use the LPS as a way to interact with their host once they have managed to infiltrate the system. That being said, not all spirochetes contain LPS. In fact, research published less than a decade ago found that borrelia burgdorferi actually lacks LPS. That has recently changed, though, as new studies investigating the structure of the bacteria have found that, although the LPS isn’t typical of spirochetes in general, it is still there in the bacteria that causes Lyme disease.
How do bacteria structure and borrelia lipopolysaccharides play a role in Lyme disease pathogenesis?
The study previously mentioned has found that LPS, which helps bacteria invade its host and travel through thick liquids and other substances, is found in the borrelia burgdorferi bacteria. Up until recently, it wasn’t certain whether this bacteria even had LPS at all. This new finding has given way to more information regarding how the bacteria uses its unique structure to infiltrate a human host and cause Lyme disease.
Both LPS and the bacterial structure make borrelia burgdorferi a dangerous player, because it can easily makes its way into human tissues when it has entered through the bloodstream. This ability to essentially hide out gives it the upper hand against our treatment methods.
These new findings could pave the way for even more structural information that can aid in the development of new and more effective treatment for Lyme disease.