Primary Streptococcus viridans pneumonia

Chest. 1989 Oct;96(4):831-4. doi: 10.1378/chest.96.4.831.


We describe three cases of acute uncomplicated bacterial pneumonia due to viridans streptococci in previously healthy adults, which were indistinguishable from those caused by other well-known respiratory pathogens. On arrival, all of these patients were treated with IV aqueous penicillin based on Gram stain of sputum which showed predominant Gram-positive cocci in pairs and chains. These specimens of sputum grew normal oral flora in the three cases. The diagnosis was confirmed by positive blood cultures in all three patients from each of two separate samples of blood. The isolates were identified as S uberis. There is no precedent in the literature of primary pneumonia due to viridans streptococci complicated by bacteremia in normal adults. We wonder if primary pneumonia due to viridans streptococci is not as rare as has been reported in the literature. Also, Gram stain of the sputum had a very significant contribution in the initial management of these patients. All of these patients subjectively showed improvement in 24 hours and became afebrile within three days of starting penicillin therapy.

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Male
  • Penicillins / therapeutic use
  • Pneumonia / drug therapy
  • Pneumonia / etiology*
  • Sputum / microbiology
  • Streptococcal Infections / drug therapy
  • Streptococcal Infections / microbiology*
  • Streptococcus / isolation & purification


  • Penicillins