Physician

GPCC - S. aureus/CNS PNA FISH

For in vitro diagnostic use.

S. aureus/CNS PNA FISH™ (Cat. No. KT005) is a multicolor, qualitative nucleic acid hybridization assay intended for identification of Staphylococcus aureus and selected other staphylococci from blood cultures.

S. aureus/CNS PNA FISH provides rapid identification of S. aureus and non-aureus staphylococci, commonly referred to as Coagulase-Negative Staphylococci (CNS), on smears made directly from Gram-positive cocci in clusters (GPCC) positive blood cultures. S. aureus/CNS PNA FISH is compatible with all major blood culture media. The 2.5 hour fluorescence in situ hybridization (FISH) assay uses fluorescently labeled peptide nucleic acid (PNA) probes that target the species-specific ribosomal RNA (rRNA) in S. aureus and CNS. Results are visualized using fluorescence microscopy. Green fluorescing cells identify S. aureus while red fluorescing cells identify Coagulase-Negative Staphylococci (CNS). The absence of fluorescence indicates another species is present in the positive blood culture.

Features and Benefits

Results Reporting - Rapid Identification of GPCC+ Blood Cultures

Once a blood culture turns positive, a Gram stain is performed. If the Gram stain reveals Gram-positive cocci in clusters (GPCC), S. aureus/CNS PNA FISH is performed and within a few hours, results are available and can be reported to the attending physician.

Reducing Mortality and Costs Associated with S. aureus Bloodstream Infections
- Early Identification of S. aureus from GPCC+ Blood Cultures
- Support Early and Aggressive Therapy 

S. aureus infections present a considerable challenge that lead to increased mortality, longer length of stay (LOS) and significant costs to hospitals. In the United States, more than 300,000 patients contract a S. aureus infection leading to more than 12,000 deaths, 2.7 million excess LOS days and close to $9.5 billion in excess hospital charges (1). Rapid identification of S. aureus, especially in positive blood cultures, is crucial to ensuring early, aggressive and effective therapy.

A study presented at the 2007 Annual Meeting of the Society for Healthcare Epidemiology of America (SHEA) by a team of infectious diseases specialists at the Washington Hospital Center (2), showed that implementing PNA FISH and rapid reporting of S. aureus results to physicians led to:

• Significant reduction in ICU related mortality due to S. aureus and BSI’s

• Median hospital cost savings of $19,441 per patient

Reducing Costs Associated with CNS Contaminated Blood Cultures
- Reduce Vancomycin Use and Length of Stay (LOS)
- Improve Bed and Resource Utilization
- Reduce Hospital Bed, Pharmacy and Laboratory Costs

Positive blood cultures don’t always constitute true infections. In fact, even though only about 10% of all blood cultures performed annually in the United States turn positive, indicating a bloodstream infection, 30% or more of those turn positive due to contamination with Coagulase-Negative Staphylococci which is commonly found on the skin. However, because these bacteria are closely related to S. aureus, which almost always causes true and serious infections, patients with CNS contaminated blood cultures are often unnecessarily treated with broad-spectrum antibiotics, especially vancomycin, leading to longer hospital stays.

A study published in the July 2006 issue of the Journal of Antimicrobial Agents and Chemotherapy by the University of Maryland Medical Center (3), showed that early detection of CNS contaminated blood cultures using PNA FISH resulted in:

• Significant reduction in unnecessary vancomycin use

• Reduction in median hospital length of stay of 2 days (from 6 to 4 days)

• Increased bed utilization

• Cost savings per patient of $4,005. The cost savings included $2,704 in reduced bed costs, $985 in reduced pharmacy costs and $316 in reduced laboratory costs.

1. Noskin et al. The burden of Staphylococcus aureus infections on hospitals in the United States: an analysis of the 2000 and 2001 Nationwide Inpatient Sample Database. Arch Intern Med. 2005 Aug 8-22;165(15):1756-61.

2. Ly et al. Impact Upon Clinical Outcomes of Translation of PNA FISH generated Laboratory Data From the Clinical Microbiology Bench to Bedside in Real Time. SHEA 2007. Baltimore, Maryland.

3. Forrest et al. Impact of rapid in situ hybridization testing on coagulase-negative staphylococci positive blood cultures. J Antimicrob Chemother. 2006 Jul;58(1):154-8