(ag″rō-bak-tēr′ē-ŭm rā″dē-ō-bak′tĕr) [L. fr. Gr.] The former name of the bacterium now called Rhizobium radiobacter. It is a gram negative rod shaped bacterium. It is an opportunistic pathogen that is a rare cause of bacteremia, endocarditis, and peritonitis mostly in mostly in immunocompromised patients, and is a rare cause of urinary tract infection.