Streptococcus Anginosus Group-associated Pyogenic Liver Abscess.

A 49-year-old woman with diabetes mellitus was referred to our hospital because of general malaise. Imaging studies and percutaneous drainage resulted in a diagnosis of pyogenic liver abscess (PLA) (Picture 1). Bacterial cultures of blood, aspirates from the abscess, and the dental plaque all grew Streptococcus anginosus. She had untreated periodontitis and resultant tooth losses in the natural course (Picture 2). She also had concomitant septic pulmonary embolisms with cavitations and feeding vessel sign (arrow in Picture 3). Despite a huge PLA, the serum levels of bilirubin, alanine aminotransferase, alkaline phosphatase, and procalcitonin were normal. The Streptococcus anginosus group (SAG), which consists of Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus, is normal flora of the human oral cavity and gastrointestinal tract. It can cause contiguous or distant infections, and notably, abscesses (1). SAG-associated PLAs often show less pronounced serum liver enzymes and biomarkers, and longer incubation periods than other PLAs (2). Furthermore, patients with SAG-associated PLAs frequently have diabetes mellitus, poor oral hygiene, ulcerated gastrointestinal diseases, and thoracic spread of infections. SAG should therefore be recognized as an emerging pathogen that can cause PLAs.

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The authors state that they have no Conflict of Interest (COI).