[A case of bacterial pneumonia caused by Streptococcus dysgalactiae subsp. equisimilis, showing patchy consolidations resembling organizing pneumonia].

: In December, 2001, a 67-year-old woman was given a diagnosis of having systemic sclerosis and organizing pneumonia. Steroid treatment improved her condition, and she received no further medication for approximately three years thereafter. In October 2005, she visited Kurume University Hospital because of cough and fever. Chest X-ray film and high-resolution computed tomography (HRCT) showed bilateral patchy consolidation with air-bronchogram sign and ground-glass opacities, predominantly in the right lower lung field, suggesting relapse of organizing pneumonia. However, bronchoalveolar lavage fluid (BALF) analysis showed an increase of neutrophils (79%) and the CD4/CD8 ratio (4.04). Streptococcus dysgalactiae subsp. equisimilis (beta-hemolytic, Lancefield group G) was detected by bacterial culture of the BALF. Treatment with sulbactam sodium/ampicillin sodium (SBT/ ABPC) rapidly improved her symptoms. The patchy consolidations on chest X-ray and HRCT also disappeared after the treatment. On the basis of these clinical and bacteriological findings, we diagnosed the patient as having bacterial pneumonia caused by Streptococcus dysgalactiae subsp. equisimilis.