noun. Any of various gram-negative, rod-shaped bacteria of the genus Proteus, certain species of which are associated with human enteritis and urinary tract infections.

noun. Any of many gram-negative bacteria, of the genus Proteus, several of which are responsible for human infections.

"And, then, there's the discussion of the Ohio "proteus," which appears to puzzle the editor, who doesn't seem aware that "proteus" was commonly used historically as a generic term for aquatic salamanders."