There are many species
Some harmful some not!
Some are man made.

Crystalline Brucella and Multiple Sclerosis

In 1998 in Rochester, New York, A former military man, PFC Donald Bentley, has a document that says : "I was in the US Army, and I was trained in bacteriological warfare. We were handling a bomb filled with brucellosis, only it wasn’t brucellosis; it was a Brucella toxin in crystalline form. We were spraying it on the Chinese and North Koreans."

He has a certificate listing his training in chemical, biological and radiological warfare. Then he has 16 pages of documents given to him by the US military when he was discharged from the service. They linked brucellosis with multiple sclerosis, and stated in one section: "Veterans with multiple sclerosis, a kind of creeping paralysis developing to a degree of 10% or more disability within two years after separation from active service, may be presumed to be service-connected for disability compensation. Compensation is payable to eligible veterans whose disabilities are due to service." In other words: "If you become ill with multiple sclerosis, it is because you were handling this Brucella, and we will give you a pension. Don’t go raising any fuss about it." In these documents, the government of the United States revealed evidence of the cause of multiple sclerosis, but they didn’t make it known to the public—or to your doctor.