Mycotic Aneurysm Caused by Streptococcus Constellatus Subsp Constellatus

An infected mycotic aneurysm due to Streptococcus constellatus subsp. constellatus has not previously been reported. We report on this condition in an 87-year-old woman who had aggravating abdominal pain and a large fusiform aneurysm over the thoracic-abdominal aorta with mural thrombus. Isolates from two sets of blood cultures and the debrided tissue were identified as S. constellatus subsp. constellatus by their biochemical reaction profiles, compatible 16S rRNA gene sequencing results, and sequencing results for the partial groESL gene and the 16S-23S intergenic spacer region