[Pleural empyema due to Streptococcus milleri].

Thus far little attention has been focused on the precise identification of Streptococcus viridans to species level and the clinical relevance of Streptococcus milleri, yet there is growing evidence that closer identification would be of significant clinical value. Streptococcus milleri was identified in 142 isolates from approximately 120 patients over a period of 12 months (June 1984-May 1985) at the Institute of Medical Microbiology, Zurich University Hospital. Pleural empyema was the source in eleven patients (10%). The presentation of six cases of pleural empyema in which Streptococcus milleri played a role, together with a review of the literature, may serve to emphasize the importance of an organism whose taxonomic status is still unclear.