ABSTRACT
In the microbiological diagnosis of bloodstream infections (BSI), blood culture (BC) is considered the gold standard test despite its limitations such as low sensitivity and slow turnaround time. A new FDA-cleared and CE-marked platform utilizing magnetic resonance to detect amplified DNA of the six most common and/or problematic BSI pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli; referred to as ESKAPEc) is available and may shorten the time to diagnosis and potentially improve antimicrobial utilization. Whole blood samples from hospitalized patients with clinical signs of sepsis were analyzed using the T2Bacteria Panel (T2Biosystems) and compared to simultaneously collected BC. Discrepant results were evaluated based on clinical infection criteria, combining supporting culture results and the opinion of treating physicians. A total of 55 samples from 53 patients were evaluated. The sensitivity and specificity of the T2Bacteria panel was 94% (16 out of 17 detections of T2Bacteria-targeted organisms) and 100%, respectively, with 36.4% (8 of 22) causes of BSI detected only by this method. The T2Bacteria Panel detected pathogens on average 55 hours faster than standard BC. In our study, 9 of 15 patients with positive T2Bacteria Panel results received early-targeted antibiotic therapy and/or modification of antimicrobial treatment based on T2Bacteria Panel findings. Given the high reliability, faster time to detection, and easy workflow, the technique qualifies as a point-of-care testing approach.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antimicrobial Stewardship/methods , Bacteremia/microbiology , Blood/microbiology , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Bacteremia/blood , Bacteremia/drug therapy , Blood Culture , Enterococcus faecium/drug effects , Enterococcus faecium/genetics , Enterococcus faecium/isolation & purification , Escherichia coli/drug effects , Escherichia coli/genetics , Escherichia coli/isolation & purification , Humans , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/isolation & purification , Prospective Studies , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/isolation & purification , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purificationABSTRACT
Fast and accurate detection of causative agents of bloodstream infections remains a challenge of today's microbiology. We compared the performance of cutting-edge technology based on polymerase chain reaction coupled with electrospray ionization-mass spectrometry (PCR/ESI-MS) with that of conventional broad-range 16S rRNA PCR and blood culture to address the current diagnostic possibilities for bloodstream infections. Of 160 blood samples tested, PCR/ESI-MS revealed clinically meaningful microbiological agents in 47 samples that were missed by conventional diagnostic approaches (29.4% of all analyzed samples). Notably, PCR/ESI-MS shortened the time to positivity of the blood culture-positive samples by an average of 34 hr. PCR/ESI-MS technology substantially improved current diagnostic tools and represented an opportunity to make bloodstream infections diagnostics sensitive, accurate, and timely with a broad spectrum of microorganisms covered.
