Pyogenic liver abscess caused by Streptococcus milleri. Case reports.

In recent years Streptococcus milleri has emerged as an important cause of pyogenic liver abscess. Whether this represents a changing epidemiological pattern or merely reflects the more widespread application of routine anaerobic bacterial culture techniques is unclear. The isolation of Strept. milleri on culture of a blood specimen from a patient presenting with a pyrexial illness should alert the clinician to the possibility of an underlying liver abscess. Although it is isolated anaerobically this organism should not be mistaken for an obligate anaerobe, especially since it is resistant to metronidazole. Two cases of primary pyogenic liver abscess caused by this organism are reported.