What is "midichloria"

Midichloria is a genus of Gram-negative, non- sporeforming bacteria, with bacillus shape of ~0.45 µm in diameter and ~1.2 µm in length. First described in 2004 with the temporary name IricES1, Midichloria are symbionts of the hard tick Ixodes ricinus. They live in the cells of the ovary of the females of this tick species. These bacteria have been observed in the mitochondria of the host cells, a trait that has never been described in any other symbiont of animals. Midichloria bacteria seem to consume the mitochondria they parasitize, possibly using them as a source of energy and/or molecules to multiply. The interaction of these symbionts with their host is currently unknown, though the 100% prevalence in the females of the host tick seems to suggest a mutualistic association.