Scientists have compared for the first time all known species of Leptospira bacteria: some members of this genus cause deadly diseases in humans and pets. Microbiologists have figured out what exactly makes bacteria harmful, according to the journal PLOS Neglected Tropical Diseases.
Some Leptospira species do not cause infections and feed on the waste products of living things. In rats and mice, they live in the kidneys. In cows, sheep, pigs and horses, leptospira sometimes causes kidney failure and cardiac arrest, as well as miscarriages. In humans, leptospirosis (swineherd disease) results in flu-like symptoms. In more severe cases, microbes infect the kidneys, liver, and central nervous system. Up to 60 thousand people die from this disease a year.
Scientists have identified unique proteins characteristic of the pathogenic Leptospira species. This discovery will help develop a vaccine for leptospirosis. In addition, a unique microbe defense mechanism was discovered: it synthesizes sialic acid, which allows it to hide inside the body from the cells of the immune system. Further, in the course of evolution, dangerous species of bacteria have learned to synthesize vitamin B12 from a single precursor (amino acid).
Finally, the genetic mechanism CRISPR-Cas has been found in pathogenic species, which has recently been actively used for genome editing. CRISPR-Cas gave leptospirae increased resistance to the invasion of foreign genetic elements, scientists emphasize.