Clinical Significance and Characterization of Streptococcus tigurinus Isolates in an Adult Population.
Streptococcus tigurinus is a newly described member of the Streptococcus mitis group. Due to the difficulty in distinguishing viridans group streptococci (VGS) by phenotype, analysis of 16S rRNA sequences is necessary for the accurate identification of most species. Through a laboratory policy of analyzing all clinically significant isolates from the VGS group by16S rRNA gene sequencing, we identified 14 S. tigurinus isolates from 11 patients. The Vitek 2 system most commonly gave an excellent rating to an incorrect identification (e.g., Streptococcus mitis), as did matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (e.g., Streptococcus oralis). S. tigurinus strains were recovered from numerous body sites, including the blood, peritoneal fluid, bone, synovial fluid, a perianal abscess, and an arm wound. Retrospective chart review indicated that most isolates were clinically significant, with bacteremia (n = 5), soft tissue infections (n = 3) osteomyelitis (n = 2), infected joint prosthesis (n = 2), and peritonitis (n = 2) being the most common, thus expanding the spectrum of disease associated with S. tigurinus.
Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA.
Lori
L
Bourassa
Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA Veterans Administration Puget Sound Health Care System, Seattle, Washington, USA jill.clarridge@va.gov.
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JE
Clarridge
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D010019:Osteomyelitis / Q000382:microbiology*; D010538:Peritonitis / Q000382:microbiology*; D016459:Prosthesis-Related Infections / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012189:Retrospective Studies; D018461:Soft Tissue Infections / Q000382:microbiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013290:Streptococcal Infections / Q000175:diagnosis / Q000382:microbiology*; D013291:Streptococcus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S