Successful European evaluation for staphylococci test kits shows high levels of sensitivity and specificity, as well as being much faster than the standard tube coagulase method
Oxoid's Staphytect Plus and Dryspot Staphytect Plus test kits have been successfully evaluated under the European Microbiological Methods Assessment Scheme (Emmas).
In the past, the testing of new methods has been undertaken by the individual laboratories wishing to use them.
This obviously resulted in considerable time taken, and duplication of large amounts of data.
Emmas was introduced to provide manufacturers with a system for the assessment of new methods, but also to provide the food industry with a source of information on the performance of new test kits.
The final Emmas report provides details of sensitivity, specificity and comparison to standard methods, along with other practical information such as additional requirements, cost per test, etc.
Oxoid's Staphytect Plus and Dryspot Staphytect Plus were compared with the tube coagulase method, on presumptive colonies isolated from a range of food samples including dairy products, raw meats, salads and vegetable, eggs, ready meals, sandwiches, and hand swabs.
The Oxoid kits showed very high levels of both sensitivity (98%) and specificity (97%) as well as offering the advantage of producing confirmed results 24-48 hours earlier than the standard tube coagulase method.
All the laboratories reported the kits were easy to use and the reactions were clear to interpret.
The Emmas procedure contains three phases of assessment: Phase 1 - Questionnaire: this detailed questionnaire is completed by the manufacturer, listing numerous aspects of the kit and explaining its use.
Phase 2 - Laboratory Testing: this part covers sensitivity and specificity of the test, comparing it to a standard method.
Phase 3 - End User Trial: this includes a minimum of six food industry laboratories experienced in the use of standard methods for the organism concerned.
The laboratories are generally accredited by an independent assessment organisation.
The laboratories supply all the data they generate from both the standard method and the test method.
The Emmas report contains all the above information, giving details of methods, food sample types used, statistical analysis etc.
This provides any company wishing to use the new method with a complete guide to its use and performance characteristics, thereby reducing the amount of in-house testing they are required to do themselves in order to meet their own accreditation requirements.
