Pseudomonas mallei is an opportunistic bacterial organism from the family Pseudomonasaceae, formerly known as Bacterium malayi. It is also known as glanders bacillus (also known as glanders) because it causes glanders, a life-threatening form of plague. Pseudomonas mellei was first described in 1893 by Pasteur and Carrère based on the results of a study of water in Malaya on the Malay Peninsula (Malaysia).