Diagnostic Performance of Plasma Procalcitonin in Screening for Contamination When Detecting Potential Contaminants in Blood Cultures

Blood culture contamination is defined by the introduction into of a microorganism into blood culture bottles from either the patient's or healthcare worker's flora, or the immediate environment during specimen collection. Species considered as potentially contaminating (coagulase negative staphylococci (CNS), Bacillus spp., Corynebacterium spp., Cutibacterium acnes, Micrococcus spp., viridans group streptococci, and Clostridium perfringens) can, however, be responsible for true bacteremia. If an organism belonging to one of those species is detected in isolates, rapidly and accurately assessing its contaminant or infectious potential is hence important to ensure effective antibiotic therapy as well as to reduce financial burden caused by unnecessary treatments, and additional clinical and laboratory costs.

Blood levels of the prohormone procalcitonin (PCT) markedly increase in the early stages of bacterial infections. The aim of our study is to determine the role of plasma PCT as a biomarker differentiating blood culture contaminations from true bacteremia.