RETROGRADE TRANSMISSION OF PROTEUS-MIRABILIS DURING PLATELET TRANSFUSION AND THE USE OF ARBITRARILY PRIMED POLYMERASE CHAIN-REACTION FOR BACTERIA TYPING IN SUSPECTED CASES OF TRANSFUSION TRANSMISSION OF INFECTION

Background: When bacteria are found, after a platelet transfusion, in the recipient's blood as well as in the platelet concentrate (PC), a c ausal relationship is normally suspected, with the PC as the causative agent, The other alternative, that the patient has bacteremia and con taminated the PC, is less well documented in the literature. Case Repo rt: Arbitrarily primed polymerase chain reaction (AP-PCR) was used for testing strains of Proteus mirabilis isolated from a patient's blood before and after a platelet transfusion and from the PC. Because of a febrile reaction after a platelet transfusion, bacterial culture was p erformed on the PC used, showing growth of P. mirabilis. The same spec ies was found in the patient's blood after the transfusion, Posttransf usion sepsis caused by a contaminated PC was suspected, and anti-sepsi s treatment was given to the recipient. Later, it became apparent that the patient had had bacteremia before the transfusion and that P. mir abilis was one of the species in the isolate. With AP-PCR, the identit y of the three P. mirabilis isolates could be distinguished. Conclusio n: AP-PCR is a useful technique for distinguishing the identity of bac terial isolates from patients and blood components, A patient with bac teremia can contaminate a PC in conjunction with a platelet transfusio n. With AP-PCR, the PC could be ruled out as the cause of the posttran sfusion sepsis.