A pseudo-outbreak of Streptomyces infections linked to laboratory construction

Over a four-week period, nine isolates of Streptomyces species were identified from seven blood cultures, one infected gortex graft, and one cerebrospinal fluid (CSF) specimen. None of the patients were clinically infected or received antimicrobial therapy. Blood culture collecting tubes, iodoform prep solutions, BAC-TEC filters, and alcohol prep pads were cultured but did not reveal a source of contamination. Six additional clinical specimens became positive, and the occurrence of construction in the laboratory was considered as a source of the contaminating organism. Blood agar plates were placed for 20 minutes in an area undergoing construction. Streptomyces grew in heavy concentrations on nine of ten plates in the construction site, but only one colony on ten plates grew from a hallway not undergoing construction. Isolation of the organism ceased with cessation of the construction. The authors conclude that the Streptomyces pseudo-outbreak was related to construction around the laboratory, with probable airborne contamination of clinical specimens.