Gram negative rod.
Fever (often relapsing), rash and arthritis. The arthritis may exist without the symptoms of classic rat bite fever: "Asymmetrical polyarticular involvement of the peripheral joints is typical for streptobacillary arthritis. In contrary to streptobacillary rat-bite fever, skin rash and bacteremia is uncommon (PubMed)."
ICD9 Codes (Soon to be supplanted by ICD10)
Streptobacillus moniliformis 026.1.