Molecular Diagnosis by qPCR for the Detection of Sepsis-Associated Microorganisms: A Comparative Study with Blood Culture in Intensive Care Unit Patients

Abstract

Sepsis is a severe clinical condition characterized by a dysregulated systemic inflammatory response resulting from infection and is associated with high mortality rates. Rapid diagnosis is essential for the timely initiation of appropriate antimicrobial therapy. Although blood culture is considered the gold standard method for identifying microorganisms in the bloodstream, its low sensitivity and prolonged turnaround time may compromise therapeutic decision-making. In this context, molecular methods such as real-time polymerase chain reaction (qPCR) have emerged as promising alternatives for the rapid diagnosis of sepsis. The aim of this study was to evaluate the application of qPCR-based molecular diagnosis for the detection of sepsis-associated microorganisms and to compare its performance with conventional blood culture in patients admitted to intensive care units. The study was conducted using serum samples from 31 patients. Samples were subjected to bacterial DNA extraction followed by qPCR amplification for the detection of Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. The results were compared with those obtained by conventional blood culture. Molecular diagnosis identified microorganisms in 6 of the 31 patients analyzed (19.35%), whereas blood culture yielded positive results in only two cases, including one contamination episode and one microorganism not covered by the molecular panel. Therefore, qPCR demonstrated greater speed and sensitivity in the detection of sepsis-associated pathogens when compared with blood culture, highlighting its potential as a valuable tool for improving diagnostic accuracy and optimizing the clinical management of critically ill patients.