The influence of antimicrobial prophylaxis on the microbial and clinical findings in patients after autologous bone marrow transplantation.

The influence of a prophylactic regimen consisting of ciprofloxacin 250 mg bid, was examined by surveillance cultures from nose, throat, axilla, gingiva, exit site of central venous catheters, blood, rectum and urine of 60 patients undergoing autologous bone marrow transplantation during a 6-year period. None of the 60 patients developed any infectious with Gram-negative rods belonging to the Enterobacteriaceae, or deep fungal infections, during hospitalization. All patients were neutropenic. Febrile episodes were seen in all patients but 3. From 13 patients, microorganisms in the blood, mostly nonhaemolytic streptococci (9/13), were cultured. Surveillance cultures did not predict later infections, but revealed the marked influence of the prophylactic antibiotics on the normal flora. Thus, mainly streptococci, coagulase-negative staphylococci and yeasts were cultured from the sites examined. It is concluded that the future objective of the microbiological surveillance should be restricted to monitoring the possible selection of drug-resistant microorganisms, and that routine cultures of blood and urine are unnecessary.