The Development of a Real-Time Quantitative Polymerase Chain Reaction Method for the Diagnosis of Staphylococcus Aureus in Intravascular Catheter Colonisation

Abstract

Staphylococcus aureus (S. aureus) catheter-related bloodstream infection (CRBSI) remains a leading cause of nosocomial (hospital acquired) infection worldwide. Early detection of S. aureus as a causative organism and appropriate antibiotic therapy is crucial in reducing patient morbidity and mortality rates. Current diagnosis of S. aureus intravascular catheter (IVC) colonisation relies on the use of conventional culture-dependent methods. However, many fastidious bacteria are difficult to be recovered in current laboratory conditions. Furthermore, a definitive diagnosis following a positive culture may take up to seven days and is therefore not useful in directing early antibiotic therapy in patients with CRBSI. A real-time polymerase chain reaction (PCR) assay, using primers specific to the thermonuclease (nuc) gene, targeting the S. aureus genome has the potential to address these limitations.