Advances in Rapid Molecular Blood Culture Diagnostics: Healthcare Impact, Laboratory Implications, and Multiplex Technologies

Abstract

Background For far too long, the diagnosis of bloodstream infections has relied on time-consuming blood cultures coupled with traditional organism identification and susceptibility testing. Technologies to define the culprit in bloodstream infections have gained sophistication in recent years, notably by application of molecular methods. Content In this review, we summarize the tests available to clinical laboratories for molecular rapid identification and resistance marker detection in blood culture bottles that have flagged positive. We explore the cost–benefit ratio of such assays, covering aspects that include performance characteristics, effect on patient care, and relevance to antibiotic stewardship initiatives. Summary Rapid blood culture diagnostics represent an advance in the care of patients with bloodstream infections, particularly those infected with resistant organisms. These diagnostics are relatively easy to implement and appear to have a positive cost–benefit balance, particularly when fully incorporated into a hospital's antimicrobial stewardship program.

Evaluation of two rapid molecular test systems to establish an algorithm for fast identification of bacterial pathogens from positive blood cultures

“…The panels of the FilmArray® and ePlex® systems with their ability for detecting common antimicrobial resistance genes are suitable for fast identification and rough genotypic resistance characterization of Grampositive organisms, specifically for Staphylococcus species demarcating S. aureus and MRSAs and Enterococcus species defining VREs. Specific performance characteristics of the assays, costbenefit ratio, laboratory operating hours, manning and state of knowledge of the laboratory personnel, patient population as well as effect on patient care from individual identification panels affect the advantages of rapid PCR-based blood culture diagnostics implicating the need of a considered selection and implementation of a rapid molecular ID system [39].…”

Clinical Performance of the Novel GenMark Dx ePlex Blood Culture ID Gram-Positive Panel

“…There are several possible reasons for this observation, such as detection of nonviable organisms, as has been observed in other studies of molecular assays or contamination. Finally, biological contamination due to presence of nucleic acid from an organism introduced during manufacturing of the blood culture bottle broth has been reported (69). With respect to this, there were no observed patterns of repeated detection of an organism that was not seen on Gram stain.…”

<p>Pediatric Antimicrobial Stewardship Programs: Current Perspectives</p>

“…These analyses can then be used to help justify the often expensive upfront costs of equipment purchasing and implementation. 65,66 Rapid pathogen identification theoretically allows for a shortened time interval between antibiotic initiation and optimization. However, such benefits can be negated in the absence of existing decision support structures to assist with testing interpretation and provide real-time clinical guidance.…”

“…67 The verbiage for reporting certain bacterial genetic resistance determinants (eg, presence of the mecA gene encoding for methicillin resistance in a Staphylococcus aureus isolate) detected by various rapid molecular diagnostics should be carefully crafted and reviewed by a multidisciplinary team of laboratory personnel, ID specialists, ASP team members and infection preventionists prior to dissemination. 66…”