Three Color Test for Simultaneous ID of Gram Negs Directly from Blood Cultures

AdvanDx have launched its CE-IVD marked GNR Traffic Light™ PNA FISH® test in Europe. GNR Traffic Light PNA FISH is the first-ever test capable of simultaneously identifying Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa directly from positive blood cultures in less than 90 minutes.

The GNR Traffic Light is the latest addition to AdvanDx's easy-to-use, molecular-based PNA FISH diagnostics platform designed to provide rapid, therapy-guiding results enabling clinicians to provide early, effective therapy for patients with Gram-negative bloodstream infections.

Every year, an estimated 100,000 patients develop bloodstream infections (BSI) due to Gram-negative pathogens, mainly E. coli, K. pneumoniae and P. aeruginosa. Patients afflicted by these serious infections spend an average of 15 days in the hospital, suffer mortality rates as high as 40% and cost institutions between $40,000 to $60,000 per case^1,2 . These grim statistics are due in part to Gram-negative bacteria's increasing resistance to a multitude of antibiotic agents, especially in P. aeruginosa and increasingly in K. pneumoniae, creating complex therapy decisions for clinicians. Treatment challenges are further compounded by conventional laboratory testing methods that take 24-48 hours or longer to identify the causative pathogen, forcing clinicians to treat patients empirically. This empirical antibiotic coverage can lead to both unnecessary treatment with broad-spectrum antibiotics as well as inadequate treatment if highly virulent and resistant pathogens are not suspected and covered for.

Studies show that providing a 24 hours 'head start' on appropriate, narrow-spectrum therapy for Gram-negative bloodstream infections may improve clinical outcomes, reduce antibiotic resistance rates and reduce the incidences of adverse events^3,4. GNR Traffic Light PNA FISH will enable microbiology labs to provide clinicians rapid, accurate Gram-negative pathogen identification results in hours, instead of days.

'The GNR Traffic Light PNA FISH test demonstrates AdvanDx's commitment to developing cutting-edge molecular diagnostic products that provide fast results for these serious infections.' said Thais T. Johansen, President and CEO of AdvanDx. 'This latest PNA FISH test provides another tool to help laboratories and clinicians improve antibiotic selection, care and outcomes for critically ill patients with bloodstream infections.' Johansen concluded.
PNA FISH is an easy-to-use and highly sensitive and specific fluorescence in situ hybridization (FISH) assay that uses PNA (peptide nucleic acid) probes to target species specific ribosomal RNA (rRNA) in live bacteria and yeast. The unique properties of the non-charged, peptide backbone of PNA probes enable the use of FISH assays in exceedingly complex sample matrixes, such as blood and blood cultures, and this in turn facilitates the development of very simple, yet very accurate tests that don't require the extensive sample preparation necessary for other nucleic acid technologies.

PNA FISH tests enable microbiology labs to provide rapid and accurate identification of bloodstream pathogens directly from positive blood cultures in hours instead of days. Clinical studies show that rapid identification of bloodstream pathogens using PNA FISH tests leads to more appropriate patient therapy that saves lives and reduces unnecessary antibiotic use, patient length of stay and hospital costs.

References:
1. Kang et al. Bloodstream Infections Caused by Antibiotic-Resistant Gram-Negative Bacilli: Risk Factors for Mortality and Impact of Inappropriate Initial Antimicrobial Therapy on Outcome. Antimicrobial Agent and Chemotherapy. 2005 Feb; 49:760-766

2. Paterson et al. Impact of Antibiotic Resistance in Gram-Negative Bacilli on Empirical and Definitive Antibiotic Therapy. Clinical Infectious Diseases. 2008; 47:S14-20

3. Slama et al. Gram-negative antibiotic resistance: there is a price to pay. Critical Care. 2008 May;12 Sup 4:1-9

4. Thom et al. Impact of Empiric Antimicrobial Therapy on Outcomes in Patients with Escherichia coli and Klebsiella pneumoniae Bacteremia: A Cohort Study. BMC Infectious Diseases. 2008 Sept; 8(116)

5. Al-Rawajfah et al. Incidence of and Risk Factors for Nosocomial Bloodstream Infections in Adults in the United States. Infect. Control Hosp Epedimiol. 2009 Nov; 30(11):1036-44

6. Wier et al. Diagnostic Groups with Rapidly Increasing Costs, by Payer, 2001-2007. HCUP Statistical Brief #91. 2010 June; Agency for Healthcare Research and Quality, Rockville, MD.