The pathogen of Rigelian fever.
Rigelian fever is a disease originating from the Rigel system. The only known cure is the rare mineral ryetalyn.
In 2152, Crewman Fisher came down with Rigelian fever after a visit to Tessik Prime. (ENT: "Dead Stop")
In 2154, a sample of this disease's pathogen was stored at Cold Station 12 for study. (ENT: "Cold Station 12")
In 2269, the crew of Federation starship USS Enterprise became infected, and visited the planet Holberg 917G which had rich natural ryetalyn deposits. There they encountered the immortal Flint and his android partner Rayna Kapec. (TOS: "Requiem for Methuselah")
- The term "gram-positive" implies that the pathogen is a bacterium.
Apocrypha
Rigelian fever (spelled "Rigellian" fever, though) was a plot device in two of the twenty story arcs in the Star Trek newspaper comic strip