Diagnosis and Management of Bloodstream Infections With Rapid, Multiplexed Molecular Assays

Abstract

Bloodstream infection is a major health concern, responsible for considerable morbidity and mortality across the globe. Prompt identification of the responsible pathogen in the early stages of the disease allows clinicians to implement appropriate antibiotic therapy in a timelier manner. Rapid treatment with the correct antibiotic not only improves the chances of patient survival, but also significantly reduces the length of hospital stay and associated healthcare costs. Although culture has been the gold standard and most common method for diagnosis of bloodstream pathogens, it is being enhanced or supplanted with more advanced methods, including molecular tests that can reduce the turnaround time from several days to a few hours. In this article, we describe two rapid, molecular bloodstream infection panels that identify the most common pathogens and associated genetic determinants of antibiotic resistance - the Luminex^® VERIGENE^® Gram-Positive Blood Culture Test and the VERIGENE^® Gram-Negative Blood Culture Test. We conducted a search on PubMed to retrieve articles describing the performance and impact of these tests in the clinical setting. From a total of 48 articles retrieved, we selected 15 for inclusion in this review based on the type and size of the study and so there would be minimum of three articles describing performance and three articles describing the impact post-implementation for each assay. Here we provide a comprehensive review of these publications illustrating the performance and clinical utility of these assays, demonstrating how genotypic tests can benefit diagnostic and antimicrobial stewardship efforts.

Keywords: antibiotic resistance; antimicrobial stewardship; bloodstream infection; microarray; molecular diagnostics.

Figure 1

Composition of the VERIGENE^® System. (A) The VERIGENE System includes the VERIGENE Reader, the Processor SP, and the consumables for the specific assay. (B) The VERIGENE test consumables include the VERIGENE Test Cartridge, the extraction tray, the pipette assembly, and the utility/amp tray.

Figure 2

The VERIGENE^® workflow as compared to traditional blood culture. Positive blood cultures are evaluated by Gram stain and the appropriate VERIGENE Blood Culture Nucleic Acid Test is selected. Set-up, running the test, and reporting can be easily completed within 3 hours. With traditional culture-based workflows, subculture can add an additional 12 hours, and resistance testing (when required) can add another day so that the final results may not be available for 48 hours.