Oxoid test improves on MRSA detection time
Staphylococcus aureus (MRSA) a day earlier then traditional
antimicrobial susceptibility testing (AST) gives fresh impetus to
treatment and infection control efforts that have been previously
hampered.
The laboratory test represents a solution for the pharmaceutical industry, which face a number of key challenges, in particular a reduction in the useful lifespan of antibacterial products.
Staphylococci are a leading cause of nosocomial and community-acquired infections worldwide. In many institutions, approximately 25 per cent to 50 per cent of S. aureus strains and 75 per cent of coagulase-negative staphylococci (CoNS) are resistant to methicillin. MRSA are of particular concern because of the ease with which certain epidemic strains spread and colonise debilitated patients.
The availability of this test comes after UK Health Secretary, John Reid, announced that hygiene issues and hospital-acquired infections would be the top priority for England's new Chief Nursing Officer, Chris Beasley.
Early detection of methicillin resistance in S. aureus isolates is important if subsequent actions (such as isolation, infection control and directed therapy) are to be effective. The Oxoid PBP2' Test claims to be quicker and easier to perform than genotypic tests, such as PCR requires minimal labour and no expensive or complicated equipment.
Oxoid's test is specifically a rapid latex agglutination assay, detecting the protein PBP2 (also called PBP2a), in isolates of Staphylococcus, as an aid in identifying MRSA and methicillin-resistant coagulase-negative staphylococci.
The test directly detects the PBP2 protein encoded by the mecA gene, considered the gold standard in the determination of methicillin-resistance because of its accuracy, but this method is labour-intensive and expensive to perform
Oxoid's test has the advantage of direct detection of the PBP2 protein performed in a rapid timeframe with minimal labour. False-positive results will not occur with strains that possess mecA but are unable to produce the protein product of the gene. In addition, the assay does not detect strains that are hyperproducers of either beta-lactamase or PBPs.
A spokesman for Oxoid told LabTechnologist.com: "Our test compares favourably in terms of cost when compared to slower, more laborious tests such as PCR. We're confident there is no compromise in accuracy or sensitivity."
"Latex particles sensitized with a monoclonal antibody against PBP2 will specifically react with methicillin-resistant staphylococci to cause agglutination visible to the unaided eye."
The test conforms to both the EARSS (European Antimicrobial Resistance Surveillance System) guidelines for confirmation of non-susceptible S aureus isolates and the NCCLS guidelines for the detection of oxacillin resistance.
Bacterial resistance to antibiotics is now a serious health threat worldwide, as hospital infections such as vancomycin-resistant enterococci (VRE) and MRSA are being found in the general community. Drug treatment for these strains are limited and require an intensive program, often needing extended periods in hospital.
Treatment of sensitive strains with penicillinase-resistant penicillins (PRP), is preferred as beta-lactam drugs are more easily absorbed into body fluids and tissues, cause fewer complications from treatment, and do not select for vancomycin-resistant organisms.
Oxoid's PBP2 Latex Agglutination Test is available now on the company's website.
