Streptococcus intermedius causing infective endocarditis and abscesses: a report of three cases and review of the literature.
BACKGROUND
Streptococcus intermedius is a member of the Streptococcus anginosus group. Clinical disease with S. intermedius is characterized by abscess formation and rarely endocarditis. Identification of Streptococcus intermedius is difficult, leading to the development of molecular methods to more accurately identify and characterize this organism.


METHODS
Over a period of 6 months we encountered three cases of invasive Streptococcus intermedius infection presenting as hepatic abscesses, brain abscess, and endocarditis. We confirmed our microbiologic diagnosis through 16S sequencing and found a common virulence gene in each case.


CONCLUSIONS
Our report illustrates three different clinical manifestations due to Streptococcus intermedius infection that can be encountered in healthy individuals in a community hospital setting. To our knowledge, this is the first case of Streptococcus intermedius endocarditis confirmed by 16S sequencing analysis. The use of molecular methods may allow a better understanding of the epidemiology and pathogenesis of this organism.
Tran
MaryAnn P
MP
Department of Medicine, Infectious Diseases Division, Michigan State University, East Lansing, Michigan, USA. maryann.tran@hc.msu.edu
Caldwell-McMillan
Molly
M
Khalife
Walid
W
Young
Vincent B
VB
D000293:Adolescent; D000328:Adult; D001426:Bacterial Proteins / Q000235:genetics; D001922:Brain Abscess / Q000382:microbiology*; D004697:Endocarditis, Bacterial / Q000382:microbiology*; D005260:Female; D006801:Humans; D008100:Liver Abscess / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000382:microbiology*; D034367:Streptococcus intermedius / Q000235:genetics / Q000302:isolation & purification*; D037521:Virulence Factors / Q000235:genetics
D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D037521:Virulence Factors