“A long time ago in a galaxy far, far away…” was the opening line of the first Star Wars film from 1977. In the Star Wars universe, the minuscule midi-chlorians play a major role: they are intelligent, symbiotic micro-organisms that are present in every cell and form the basis of life. When there are enough midi-chlorians in the cells, this enables the host to connect with The Force, a super-human power that plays a central role in the Star Wars stories. Star Wars’ midi-chlorians are loosely based on the available knowledge at the time of mitochondria – the power plants in our cells that were once independent organisms, but now form a standard part of all plant and animal cells*.But what do modern American fairy tales have to do with Lyme research? Well, perhaps more than you think, even apart from the eternal battle between Good and Evil …
If you have ever been bitten by a tick, there is a significant chance that you now also have midi-chlorians! To be precise, a micro-organism called Midichloria mitochondrii* that belongs to the order of Rickettsiales. Evolutionary speaking, these Rickettsiales are closely related to organisms that once evolved into our mitochondria; in that sense Midichloria is very much connected to our ‘force of life’. Unfortunately, as far as is known, the real Midichloria does not incorporate super-human powers. Data about this micro-organism is scarce, but recent publications show that it deserves more attention (1-3).
Many hard ticks, such as Ixodes ricinus, are infected with Midichloria – it is present in all females and about half of all the male ticks. The endosymbiont is located inside the cells of the tick, and in particular in the mitochondria, which it slowly consumes. Incidentally, the tick itself does not seem to be affected. Midichloria is the first micro-organism that is known to be able to multiply in the mitochondria. Midichloria probably exploits the force field (“The Force”?) between the inner and outer membrane of the mitochondria. Aside from ticks, Midichloria and closely related organisms have also been found in various other arthropods that can transmit diseases to humans. It was initially thought that Midichloria mainly appears in the ovaries of the tick and is then transovarially transmitted to the eggs and larvae. It is now clear that it is also present in the salivary glands and the saliva of the tick, which makes transmission to hosts of the tick possible.
Many mammals that can be bitten by ticks and a majority of patients with a tick bite (but not healthy humans) indeed appear to have antibodies against this organism, and sometimes also DNA and RNA of Midichloria. The extent to which the micro-organisms permanently infect human cells or mitochondria and cause disease symptoms is still unclear. There is no knowledge of distinct symptoms that belong to a human Midichloria infection. But that does not mean much considering the short-sightedness in virtually all medical tick bite research. Most physicians and researchers are not up to date with Midichloria and there are no diagnostic tests available. Since Midichloria occurs this frequently in ticks, most Borrelia infections are probably accompanied by a Midichloria infection, so it is hard to say which of the two is the cause of certain symptoms. Because of its intracellular location, Midichloria is relatively insensitive to antibiotics, so presumably once you have it, it is very hard to get rid of …
It seems obvious to me that adverse effects can happen when your body’s power plant is infected by a foreign micro-organism – for example the severe fatigue that many chronic Lyme patients experience. Incidentally, other explanations can be found for the severe fatigue, for example so-called “oxidative stress”, that is supposed to be caused by the immune system’s reaction to Borrelia and that, among other things, can damage the mitochondria. In addition to direct damage, there could also be indirect influences on the host. A somewhat similar endosymbiont, Wolbachia, can exert profound influence on properties and behaviour of the host and on other pathogens present. To what extent Midichloria mitochondrii should be added to the list of co-infections of tick bites remains unclear, but this emphasizes once again how little we still know in this area and that more research is urgently needed (but preferably without the usual short-sightedness).
* According to the Endosymbiont or Symbiogenesis theory (4), the cells of eukaryotes – including all higher organisms – originated because in the distant past simple unicellular organisms combined to form a more advanced type of cell. The groundwork of this theory was invented over a century ago by Russian researchers and was elaborated by biologist Lynn Margulis, first wife of astronomer and exobiologist Carl Sagan. Initially, symbiogenesis was a scientific fairy tale: numerous scientific journals consigned Margulis’ theory straight to the trash pile and for many years after its first publication in 1967 it was ignored by most scientists. So at the time of the first Star Wars film, symbiogenesis was still a fairly revolutionary concept. But nowadays symbiogenesis is generally accepted and is seen as a key step in the evolution of higher life forms. The only thing still under discussion, is the role of spirochetes in the evolution of our cells – something Margulis later added to the original concept. The real Midichloria was discovered in 2004 by an Australian Lyme researcher; the scientific name Midichloria mitochondrii dates from 2006 and is based on the creatures from the Star Wars film (5).
- Humans parasitized by the hard tick Ixodes ricinus are seropositive to Midichloria mitochondrii: is Midichloria a novel pathogen, or just a marker of tick bite?(2012)
- Molecular and serological evidence for the circulation of the tick symbiont Midichloria (Rickettsiales: Midichloriaceae) in different mammalian species (2013)
- Ixodes ricinus and Its Endosymbiont Midichloria mitochondrii: A Comparative Proteomic Analysis of Salivary Glands and Ovaries (2015)
Written by Niek Haak
Translated by Maartje Koster: www.maartjekoster.nl.
Aangepast: 30 oktober 2015