Oxoid Makes Screening For Antibiotic-Resistant Organisms Faster, Allowing For Swifter Infection Control And Patient Treatment

Main Category: Infectious Diseases / Bacteria / Viruses
Article Date: 29 May 2009 - 4:00 PDT

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Oxoid, a world leading microbiology brand, has today announced the availability of two new chromogenic media in the Brilliance™ Resistant Screening Agar range. Brilliance ESBL Agar and Brilliance VRE Agar can be used as screening tests to rapidly identify patients colonised with problematic Extended Spectrum Beta-Lactamase (ESBL) producing organisms and vancomycin resistant enterococci (VRE), allowing appropriate infection control and treatment to commence sooner for the best possible patient outcome.

Brilliance ESBL Agar provides presumptive identification of ESBL-producing E. coli and the Klebsiella, Enterobacter, Serratia and Citrobacter (KESC) group, direct from clinical samples. Supplied in convenient, ready-to-use plates, results are available in just 24 hours. The semi-opaque background of the medium contrasts with the brightly coloured colonies and allows clear and easy differentiation of E. coli (blue colonies) and the KESC group (green colonies). The inclusion of Cefpodoxime, a well recognised marker for ESBL mediated resistance, inhibits most non-ESBL Enterobacteriaceae. Inhibition of AmpCs reduces incidence of false-positive results compared to traditional media minimising confirmatory testing.

Brilliance ESBL Agar has recently been selected by MOSAR (the FP6 EC funded project co-ordinated by the French Inserm) for use in a pioneering European ESBL prevalence study.

Brilliance VRE Agar is a chromogenic screening plate for the detection of VRE. Following direct inoculation from faecal sample, swab, isolate or suspension, the medium provides presumptive identification of Enterococcus faecium and Enterococcus faecalis within 24 hours. Differentiation of vancomycin resistant E. faecium from E. faecalis is achieved through the inclusion of two chromogens that are targeted by specific enzymes. The action of these enzymes on the chromogens results in a build-up of colour within the colony. The colour produced depends on which enzymes the organisms possess. Additional antibiotics are present in combination with vancomycin, to suppress the growth of competing flora including E. gallinarum and E. casseliflavus, both of which are intrinsically resistant to vancomycin.

Early presumptive identification of ESBL-producing organisms and VRE permits appropriate treatment and infection control procedures to be adopted sooner, improving both treatment outcomes and the effectiveness of infection control measures.

Oxoid is part of Thermo Fisher Scientific Inc., the world leader in serving science.

References

1. Bell J.M., Paton J.C., Turnidge J. (1998). Emergence of Vancomycin Resistant Enterococci in Australia: Phenotypic and Genotypic Characteristic of Isolates. J. Clin. Microbiol. 36, 2187-2190.

2. Centers for Disease Control and Prevention (2006). Recommendations for Preventing the Spread of Vancomycin Resistance: HICPAC.

3. Delmas J., Robin F., Schweitzer C., Lesens O., Bonnet R. (2007). Evaluation of a new chromogenic medium, chromID VRE, for detection of Vancomycin Resistant Enterococci in stool samples and rectal swabs. J. Clin. Microbiol. 45, 2731-2733.

Notes

Enterobacteriaceae have become one of the most important causes of nosocomial and community-acquired infections. The main therapeutic choices to treat such infections are ß-lactam antibiotics (mainly broad spectrum penicillins and cephalosporins). However, ESBLs confer transmissible resistance to these compounds. The lack of treatment options combined with the transmissible nature of ESBL resistance mechanisms and the alarming rate at which they have spread, results in a significant threat to global public health.

Vancomycin Resistant Enterococci (VRE) have recently emerged as nosocomial pathogens, due to the increased use of vancomycin for treatment of meticillin-resistant Staphylococcus aureus in the United States of America and use of a vancomycin-like glycopeptide (avoparcin) as a growth promoter in animal husbandry in Europe1. In the U.S.A., the Centers for Disease Control and Prevention reported that as many as 1 in 3 infections amongst intensive care patients were caused by VRE2. Early detection of VRE is important for infection control and prevention measures, epidemiological infectious disease follow-up, and also prevention of vancomycin resistant Staphylococcus aureus emergence3.

Source
Thermo Fisher Scientific

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