MRSA (Mersa) Questions

New test offers extreme MRSA accuracy

Link: Microbiological evaluation of a new growth-based approach for rapid detection of methicillin-resistant Staphylococcus aureus -- von Eiff et al. 61 (6): 1277 -- Journal of Antimicrobial Chemotherapy.

Objectives: Recently, a rapid screening tool for methicillin-resistant Staphylococcus aureus (MRSA) has been introduced that applies a novel detection technology allowing the rapid presence or absence of MRSA to be determined from an enrichment broth after only a few hours of incubation. To evaluate the reliability of this new assay to successfully detect MRSA strains of different origin and clonality, well-characterized S. aureus strains were tested in this study. Methods: More than 700 methicillin-susceptible and methicillin-resistant strains covering >90% of all registered European MRSA spa types within the SeqNet network were studied. Results: All 513 MRSA strains tested were recognized as methicillin-resistant: among these, 96 MRSA strains were from an institutional collection, each presenting a unique spa type. None of the 211 methicillin-susceptible strains were detected as positive. Conclusions: The new growth-based rapid MRSA assay was shown to detect without exception all MRSA strains of large collections of strains comprising highly diverse genetic backgrounds, indicating that such a phenotypic test might be potentially more likely to cope with new strains.

International project aids MRSA response

Link: Eurosurveillance - View Article.

Several countries with a low incidence of MRSA experienced importation of epidemic MRSA from endemic MRSA countries. The HARMONY database enabled them to confirm that these MRSA strains were indeed indistinguishable from those described in their countries of origin. This enabled the international community to reflect on how the same MRSA strains were behaving in different healthcare settings and patient types. A recurring observable fact in these situations was the rapid spread of these epidemic MRSA strains on affected wards. Some of the infection control teams commented to HARMONY centres that it was far in excess of what they had encountered previously. Audits of infection control in these countries found that the spread was particularly prominent in places where hand hygiene was poor and there were also comments stating that excessive workloads and sub-optimal staffing had been a major driver. 

Getting the drugs right through active testing

Link: The Impact of mecA Gene Testing and Infectious Diseases Pharmacists' Intervention on the Time to Optimal Antimicrobial Therapy for Staphylococcus aureus Bacteremia at a University Hospital -- Carver et al., 10.1128/JCM.00801-08 -- Journal of Clinical Microbiology.

In patients with Staphylococcus aureus bacteremia, Infectious Diseases pharmacist intervention based on the results of mecA tests resulted in a a 25.4 hour reduction in the time to optimal antimicrobial therapy, from 64.7 ± 36.8 to 39.3 ± 15.5 hours (p = 0.002), which may result in decreased mortality.

Finnish Test Can Detect 50 bacteria including MRSA

Link: Finnish Biotech Company Sets World Record By Detecting 50 Dangerous Bacteria With Single Test In Quest To Battle Sepsis.

The Finnish biotechnology company Mobidiag announced the Prove-it(TM) Bacteria test that sets a world record by being able to detect 50 dangerous bacteria simultaneously - including the widespread "superbug" MRSA. This is an important milestone in the battle against infectious diseases, most importantly life-threatening sepsis. Sepsis is a growing cause of death worldwide - there are around 3 million sepsis cases annually, over 500,000 of them resulting in death. Sepsis is an infection caused by a number of micro-organisms spreading in the bloodstream. The challenge in sepsis treatment is starting adequate treatment with the appropriate antibiotics on time. Currently, the diagnostics of causative pathogen(s) needed for the antibiotic treatment decision takes 2-5 days based on blood culturing and subsequent pathogen identification. Using Mobidiag's Prove-it(TM) Bacteria, the pathogen detection is available 1-3 days earlier compared to current diagnostics. The PCR and microarray-based test takes less than three hours to complete. Achieved time saving rationalizes antibiotic treatment and improves patient outcomes and decreases mortality considerably.

A Bug Rises, and With It a Company - New York Times

Link: A Bug Rises, and With It a Company - New York Times.

Patients might not particularly like the new admission procedure at a growing number of hospitals: having what looks like an elongated Q-Tip stuck up their noses. But it smells great to Cepheid. Cepheid, a biotechnology company in Silicon Valley, sells a rapid genetic test to detect MRSA, an antibiotic-resistant “superbug” that has received considerable media coverage and kills more Americans than AIDS. With fear of the germ rising, and some states calling for mandatory screening, hospitals are snapping up Cepheid’s product in order to test incoming patients by using it with a nasal swab.

70 min test approved for Canada

Link: Cepheid Receives Health Canada Medical Device License for Xpert MRSA(TM) Test and GeneXpert(R) System: Financial News - Yahoo! Finance.

Cepheid (Nasdaq: CPHD - News) today announced that Health Canada has issued a medical device license for the Xpert(TM) MRSA test for the rapid detection of Methicillin Resistant Staphylococcus aureus (MRSA) on nasal swabs and the GeneXpert� System. Xpert MRSA test results are available in approximately 70 minutes thereby enabling rapid identification of carriers of the potential pathogen in less than two hours, from the acquisition of the patient sample to returning the result to the floor.

Rapid MRSA test gets FDA OK

Link: AMNews: Jan. 28, 2008. Rapid MRSA test gets FDA OK ... American Medical News.

Those working to control the spread of methicillin-resistant Staphylococcus aureus say this task is about to get easier. In January, the Food and Drug Administration approved the first blood test that can differentiate it from the methicillin-susceptible variant in two hours, rather than the 24 to 48 hours or longer that currently available technology takes. "[This] test is good news for the public health community," said Daniel G. Schultz, MD, director of the FDA's Center for Devices and Radiological Health. The BD GeneOhm StaphSR Assay assesses a blood sample for genetic material specific to the two main forms of these bacteria. Studies leading to the test's approval found that it could identify 100% of MRSA samples and 98% of the susceptible types. According to an FDA statement, this test should be used in patients already suspected of having a staph infection but not to monitor treatment or initially detect it. Doctors still might have to conduct follow-up testing to pin down precisely what will kill particular bacteria, but physicians say the information provided by this product will be enough to narrow down treatment choices early on.

Superbug test could cut chain of transmission

Link: Superbug test approved, cuts days off MRSA diagnosis.

This new rapid PCR test could not only save millions in terms of healthcare costs, it should allow physicians to control an outbreak of MRSA by breaking the chain of transmission. It works by using real-time polymerase chain reaction (PCR) for the amplification of MRSA DNA, detecting the amplicon linking the staphylococcal cassette chromosome mec (SCCmec) carrying methicillin-resistance (mecA) with a sequence unique to S. aureus found in the orfX gene. Unlike most PCR tests, it does not require dedicated equipment and space and can be performed without a dedicated clean area. "This allows for more appropriate isolation procedures and agent-specific antimicrobial therapy, resulting in reduced patient morbidity and mortality as well as an overall reduction in healthcare costs," said Dr Thomas Davis, Director of Clinical Microbiology, Wishard Memorial Hospital, US. The assay works directly with blood cultures and requires less technologist time than traditional microbiology assays, which can take two days to get results. BD has also submitted subsequent nasal swab and wound applications to the FDA. The firm is also developing tests for the detection of two other organisms that cause severe HAIs. These tests will identify the vanA and vanB genes associated with vancomycin-resistant enterococci and the toxin gene associated with Clostridium difficile.

FDA OKs 1st Quick MRSA Blood Test

Link: FDA OKs 1st Quick MRSA Blood Test.

The FDA today announced that it has cleared for marketing the first rapid blood test for MRSA (methicillin-resistant Staphylococcus aureus), a drug-resistant staph bacterium that can cause deadly infections. The new MRSA blood test -- called the BD GeneOhm StaphSR assay -- delivers results in two hours. Other tests take several days. "The BD GeneOhm test is good news for the public health community," the FDA's Daniel Schultz, MD, says in a news release. The new test allows for "more effective diagnosis and treatment," says Schultz, who directs the FDA's Center for Devices and Radiological Health.

VA hospitals to get easier access to Cepheid's MEMS-based test kits

Link: Small Times - VA hospitals to get easier access to Cepheid's MEMS-based test kits.

Cepheid Inc. (Nasdaq: CPHD) says it has received two Veterans Affairs Federal Supply Service Schedule contracts for the company's GeneXpert System and the Xpert MRSA test for the rapid detection of Methicillin-resistant Staphylococcus aureus, a type of bacteria that is resistant to the most-common antibiotics used in hospitals. The two contracts are expected to streamline the acquisition process and ensure VA hospitals and other federal agencies can purchase GeneXpert Systems and Xpert MRSA test kits without individual negotiations as they await funding for the next fiscal year, the company said in a news release. The kits use microfluidic technology.