Burkholderia mallei is a Gram-negative bacterium. B. mallei is responsible for causing glanders disease, which historically mostly affected animals, such as horses, mules, and donkeys, and rarely humans. Horses are considered the natural host for B. mallei infection and are highly susceptible to it.
Horses chronically infected with B. mallei with glanders disease typically experience mucus-containing nasal discharge, lung lesions, and nodules around the liver or spleen. Acute infection in horses results in a high fever, loss of fat or muscle, erosion of the surface of the nasal septum, hemorrhaging or mucus discharge. The bacterium mostly affects the lungs and airways.
Human infection with B. mallei is rare, although it occasionally occurs among laboratory workers dealing with the bacteria or those who are frequently near infected animals. The bacteria usually infect a person through their eyes, nose, mouth, or cuts in the skin. Once people are infected, they develop a fever and rigors. Eventually, they get pneumonia, pustules, and abscesses, which prove fatal within a week to 10 days if left untreated by antibiotics. The way someone is infected by the bacteria also affects the type of symptoms that will result. If the bacteria enter through the skin, a local skin infection can result, while inhaling B. mallei can cause septicemic or pulmonary, muscular, hepatic, or splenous infections.