Woburn, Mass — AdvanDx has announced that it has received FDA 510(k) clearance for its GNR Traffic Light PNA FISH test. GNR Traffic Light PNA FISH is reportedly the first test capable of simultaneously identifying Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa directly from positive blood cultures containing Gram-negative rods in less than 90 minutes.  The test is the latest addition to AdvanDx’s easy-to-use, molecular-based PNA FISH diagnostics platform designed to provide rapid, therapy-guiding results that enable clinicians to provide early, effective therapy for patients with Gram-negative bloodstream infections (BSI).


1.     Shorr et al. Inappropriate antibiotic therapy in Gram-negative sepsis increases hospital length of stay. Crit Care Med. 2011 Jan;39(1):46-51.
2.     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. Antimicrob. Agent and Chemother. 2005 Feb; 49:760-766
3.     Paterson et al. Impact of Antibiotic Resistance in Gram-Negative Bacilli on Empirical and Definitive Antibiotic Therapy. Clin Infect Dis. 2008; 47:S14-20
4.     Thom et al. Impact of Empiric Antimicrobial Therapy on Outcomes in Patients with Escherichia coli and Klebsiella pneumoniae Bacteremia: A Cohort Study. BMC Infect Dis. 2008 Sep 15;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.

Gram-negative BSIs are considered some of the most serious hospital-acquired infections and afflict more than 100,000 patients annually in the US.  The majority of these infections, approximately 70 to 80%, are caused by E. coli, K. pneumoniae and P. aeruginosa.  Increasing resistance to a multitude of antibiotic agents, especially in P. aeruginosa and increasingly in K. pneumoniae, along with slow conventional laboratory testing methods that take 2 to 3 days to identify the causative pathogen, complicate therapy decisions for clinicians.  As a result, up to one third of patients afflicted by Gram-negative BSIs initially receive inappropriate antibiotic therapy which in turn leads to higher mortality rates of up to 40%, longer hospital stays and significant extra costs.(1,2,3)  
GNR Traffic Light PNA FISH will enable microbiology labs to identify and report E. coli, K. pneumoniae and P. aeruginosa from positive blood cultures 1 to 2 days earlier than traditional methods.  The rapid results will provide clinicians a “head start” on selecting appropriate and effective therapy for patients with Gram-negative bloodstream infections which studies show may improve clinical outcomes, reduce incidence of adverse events and shorten hospital length of stay.(1,4) 
“The GNR Traffic Light PNA FISH test provides yet another cutting-edge molecular diagnostic test to the PNA FISH platform, further improving AdvanDx industry leading capability to aid laboratories and clinicians in improving antibiotic selection, care and outcomes for critically ill patients with bloodstream infections.” concluded Thais T. Johansen, president and CEO of AdvanDx.
Every year, close to 875,000 patients in the United States contract bloodstream infections, leading to over 150,000 deaths and $12 billion in patient care costs.(5,6)  The infection is detected when a culture of the patient’s blood (i.e. a blood culture) turns positive with bacteria or yeast.  Rapid and accurate identification of the specific infecting pathogen is crucial to ensure early and appropriate therapy and save patient lives.
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.