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BAX^® STAPHYLOCOCCUS AUREUS KIT (96 tests)

Code: QB2689C

BAX System Real-Time PCR Assay for Staphylococcus aureus

click here for information on BAX System Q7

Description
Staphylococcus aureus exist in the air, in water, milk, food, and on equipment and environmental surfaces. They are also a commensal organism of the human skin. Some strains of S. aureus produce enterotoxins that are not destroyed by cooking and cause illness in humans. As little as 1ng of these toxins is enough to cause illness.

Numerous foods have been implicated in S. aureus contamination including meat; poultry, eggs, dairy and associated products. It is foods that require considerable handling that are particularly associated with contamination, and if they are not stored correctly, the staphylococci can proliferate to numbers in excess of 10⁵ per gram.  It is when these levels are reached - if the strain is an enterotoxin producer – that food poisoning is likely to occur.

Current culture-based screening procedures require a laborious plating and enumeration method which typically takes three to five days.

Faster results are now available with the BAX System Real-Time PCR Assay for Staphylococcus aureus:

• For use on the BAX System Q7.
• presence/absence or threshold result:
• 20 - 22 hours enrichment.
• 90 minute processing time.
• Sensitive:  1cfu/g or 10 cfu/g depending on method.
• Colony confirmation
•  Validated on powdered infant formula and ground beef

How it works
The BAX System Real-Time PCR Assay for Staphylococcus aureus, developed in alliance with Applied BioSystems, uses probe-based chemistry and real-time PCR detection to detect very low concentrations of S. aureus in food samples. Using the power of the polymerase chain reaction (PCR), the BAX System rapidly amplifies unique DNA fragments, when present, for quick and reliable detection of S. aureus.

BAX System assays simplify the method by combining all the PCR reagents you need into a single tablet, conveniently packaged inside the PCR tubes contained in each kit. Reducing the number of manual manipulations and pipetting steps, the tableted reagents improve accuracy and consistency; hands-on time is reduced to a minimum and shelf life is increased.

For presence/absence testing, samples can be enriched for 20-22 hours and then tested with the BAX System. By modifying the sampling procedure, threshold testing can also be performed. After enrichment, samples are lysed to break open the cell walls and release DNA. This lysate is then used to hydrate the PCR tablets. Processing in the BAX System Q7 takes less than 90 minutes for a full rack of 96 tests. Electronic results appear as positive icons if S. aureus is present. A table of results for each target also allows you to view the amplification plots for the target and the internal positive control.  Data can be easily stored, shared or printed.

Applications
The BAX System detects the presence or absence of  Staphylococcus aureus at concentrations as low as 1 cfu/10-gram sample.  Customers who take action based on threshold levels can also use the BAX System to detect 10 cfu/gram or above.

Validation studies on powdered infant formula and ground beef have shown that the BAX System performs as well or better than the standard culture method, but with next-day results.

Approvals
The BAX System Real-Time PCR Assay for Staphylococcus aureus will be submitted to AOAC-RI for Performance TestedSM method approval.