Proteus vulgaris

a widespread species found in fecal matter, sewage, and soil. It is a common cause of cystitis and pyelonephritis and is associated with eye and ear infections, pleuritis, peritonitis, and suppurative abscesses. In debilitated or immunocompromised patients it can cause pneumonia (see Proteus pneumonia>, under pneumonia). The species has many serovars. The Ox antigens (Ox-2, Ox-19, Ox-K) react with antibodies formed in rickettsial infections and are used in the Weil-Felix reaction for the diagnosis of typhus, scrub typhus, and Rocky Mountain spotted fever.