Pseudosepticemia

Laboratory contamination of blood cultures with Escherichia coli resulted in initiation of treatment of seven patients who in fact did not have septicemia. Penicillinase that had been added to these blood cultures was found to contain the same serotype of E. coli that was isolated from the blood cultures. Prompt investigation resulted in recognition of the source of contamination and the discontinuance of potentially hazardous antibiotic therapy to these patients. The potential for contamination of cultures exists in all bacteriology laboratories; the ability to detect it rapidly must be insured. The availability of a designated member of the laboratory or the medical staff to review all cultures, to relate them to the clinical situation, and to make appropriate investigation into questionable situations provides an important safeguard in routine hospital practice.