Background: Former nutritionally-deficient (variant) streptococci were recently separated from other streptococci viridans to constitute a new Abiotrophia genus, subdivided into two species, Abiotrophia defectiva (ex-Streptococcus defectivus) and Abiotrophia adjacens (ex-Streptococcus adjacens).
Case report: A woman was admitted to the hospital because of purpura and fever. Vegetations were shown by trans-esophageal echocardiography. Although blood samples were positive within 24 hours, accurate identification of the morphologically and biochemically streptococcus-like bacteria that had grown remained impossible. Molecular biology technicals permitted to identify Abiotrophia defectiva, ex-Streptococcus defectivus.
Discussion: This new genus is important to be identified in clinical practice, because of the increased virulence of these bacteria, when compared with Streptococci viridans. They are also frequently penicillin-resistant. Molecular biology technicals allow precocious diagnosis, and make possible the improvement of the prognosis.