Continued Epidemiological Feature Common Microorganism Overview of VGS, Streptococcus gallolyticus (Formerly Known as Streptococcus bovis), Abiotrophia defectiva, and Granulicatella Species VGS are common pathogenic agents in community-acquired NVE in patients who are not IDUs. The taxonomy of VGS is evolving. The species that most commonly cause IE are S sanguis, S oralis (mitis), S salivarius, S mutans, and Gemella morbillorum (formerly called S morbillorum). Members of the S anginosus group (S intermedius, angi- nosus, and constellatus) also have been referred to as the S milleri group, and this has caused some confusion. In contrast to other -hemolytic streptococcal species, the S anginosus group tends to form abscesses and to cause hematogenously disseminated infection (eg, myocardial and visceral abscesses, septic arthritis, and vertebral osteomy- elitis). In addition, although the S anginosus group usually is sensitive to penicillin, some strains may exhibit variable penicillin resistance. The recommendations that follow are intended to assist clinicians in selecting appropriate antimi- crobial therapy for patients with IE caused by VGS and S gallolyticus (bovis, a nonenterococcal penicillin-susceptible group D Streptococcus). S gallolyticus (bovis) expresses the group D antigen, but it can be distinguished from group D Enterococcus by appropriate biochemical tests. Patients with either S gallolyticus (bovis) bacteremia or IE should undergo a colonoscopy to determine whether malignancy or other mucosal lesions are present. Certain VGS have biological characteristics that may com- plicate diagnosis and therapy. A defectiva and Granulicatella species (G elegans, G adiacens, G paraadiacens, and G balaenopterae), formerly known as nutritionally variant strep- tococci, are detected by automated blood culture systems but may yield pleomorphic forms by Gram stain and will not grow on subculture unless chocolate agar or other media supple- mented with pyridoxal or cysteine is used. 