Bordetella parapertussis evolved in a host population that had already developed immunity to "B. pertussis", where being able to evade "B. pertussis" immunity was an advantage. Two lineages of "B. parapertussis" have been described. The first infects humans and is responsible for a minority of cases of the disease pertussis (also known as whooping cough). The second, ovine, lineage causes chronic nonprogressive pneumonia in sheep. Both lineages are thought to have evolved from a "B. bronchiseptica"-like ancestor. This disease can be symptomatic or asymptomatic and may predispose hosts to secondary infection. Bordetella parapertussis Bordetella parapertussis is a small Gram-negative bacterium of the
Alexander disease older patients, bulbar or pseudobulbar symptoms and spasticity predominate. Symptoms of the adult form may also resemble multiple sclerosis. No more than 500 cases have been reported. Alexander disease Alexander disease is one of a group of neurological conditions known as the leukodystrophies, which are ailments caused by anomalies in the myelin, which protects nerve fibers in the brain. According to the National Institute of Neurological Disorders and Stroke, the destruction of white matter is accompanied by the formation of Rosenthal fibers—abnormal clumps of protein that accumulate in astrocytes in the brain. The most common type of Alexander disease is