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BAX® System Real-Time PCR Assay

Staphylococcus aureus

A fast solution with flexibility

Staphylococcus aureus exist in air, water, milk, food, equipment and environmental surfaces. Some strains of S. aureus produce enterotoxins that are not destroyed by cooking and cause illness in humans. According to the U.S. Food and Drug Administration, a toxic dose of 1.0 microgram can be reached when S. aureus populations exceed 100,000 per gram. 

Foods often implicated in S. aureus contamination include meat and meat products; poultry and egg products; egg, tuna, chicken, potato and macaroni salads; bakery products, especially cream-filled pastries; sandwich fillings; and milk and dairy products.Foods that require considerable handling during preparation are frequently associated with S. aureus infection. 

Culture-based screening procedures require a laborious plating and enumeration method followed by a coagulase reaction test, for results in three to five days or more.

Now you can use the BAX® System Real-Time PCR Assay for Staphylococcus aureus to get faster, automated results the day after sampling.

  • Next-day results after 22-24 hours enrichment
  • Less than 90 minutes PCR processing time
  • Detects presence/absence in powdered infant formula at concentrations as low as 1 cfu/gram
  • Can also be used for threshold testing (10 cfu/gram) on ground beef and soy protein isolate
  • Excellent inclusivity/exclusivity

How it works

The BAX® System Real-Time PCR Assay forStaphylococcus aureus 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. Tableted reagents provide for minimal hands-on time, in addition to accuracy, long shelf life and consistency.

For presence/absence testing, samples can be enriched 22-24 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 Q7 unit 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 is LIMS-compatible and can be easily stored, shared or printed.

Applications

As validated by AOAC-RI, the BAX® system is equivalent to the ISO method for detecting low levels (1 cfu/gram) of S. aureus in diluted samples of soy-or milk-based powdered infant formula. Moreover, the AOAC-RI studies found that using the BAX® system on undiluted samples actually increased sensitivity.

Ground beef customers who take action based on threhold levels can also use the BAX® system to detect at least 10 cfu/gram, with next-day results. For soy protein isolate, the enrichment time is extended to 48 hours for best results.

Approvals

AOAC-RI Performance Tested Method 120701 - applies to presence/absence testing in powdered infant formula and threshold testing (10 cfu/gram) in ground beef and soy protein isolate.

  This test kit's performance was reviewed by the AOAC Research Institute and was found to perform to the manufacturer's specifications.

Ordering info

P/N D12762689  BAX® System Real-Time PCR Assay for  Staphylococcus aureus (96 tests per kit)