Fully Automated EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) from Positive Blood Cultures: Diagnostic Accuracy and Implementation

At the end of September, the Journal of Clinical Microbiology published a remarkable study evaluating the accuracy and robustness of fully automated Rapid Antimicrobial Susceptibility Testing (RAST) directly from positive blood cultures (BCs). This paper – by A. Chekraoui and colleagues – will significantly impact the whole microbiology community, as the spread of multidrug-resistant organisms and the increase of resistant infections make RAST more valuable than ever. Let’s see what it’s all about!

Background

Although many positive BCs’ RAST methods have been released and rapid standardized disk-diffusion methods have been developed by EUCAST to enable susceptibility reports within 4 to 8 h and 16 to 18 h from positive BCs, the labor-intensive manual setup and the strictly defined reading time points have hampered their large-scale use in clinical microbiology laboratories. Nevertheless, shorter times for delivering accurate antimicrobial susceptibility results to provide patients with a rapid antimicrobial treatment remain one of the primary objectives to be achieved by microbiologists.

Here is where lab automation comes to help. In recent years, full laboratory automation has permitted the flexible, cost-effective, and accurate disk-diffusion method to return to the center stage and strengthen its position among other AST methods currently used in clinical microbiology laboratories.

What did the study find?

First, Radian interpretation demonstrated great accuracy, as the manual adjustment of the inhibition zone diameter concerned only about 5% of all tested disks.

Second, the results of the spiked BCs precisely predicted the results of the clinical trial: all antibiotics tested could be released at 4 h with high confidence, with a categorical agreement for RAST compared with the EUCAST standardized disk-diffusion test results greater than 95% for all the antibiotics tested – except for amikacin, released at 6 hrs. The only organism that posed some challenges was P. aeruginosa, and greater attention should be paid to interpreting this organism with the RAST technique.

Products transition to IVDR: completed!

We finally obtained all the certificates needed to declare the entire COPAN WASP portfolio compliant with the latest European Union In Vitro Diagnostics Regulation (IVDR).

The one-year-long process – opened last September – allows us to CE-mark all our product classes, including those that had to be evaluated and certified according to the new regulation. As a result, we can now guarantee our trusted partners and clients the continuous circulation of all our products throughout Europe without disruption.

COPAN WASP products whose IVDR compliance is covered by the certificates are classified as class A Sterile (WASP QC TSB tube), class B Medical Device Software (SOFTWARE HALO MEASURE & VISUAL, for the measurement of AST halos), and class C Medical Device Software (PhenoMATRIX, PhenoMATRIX TAG, Radian Expert System and Radian Expert System RAST, for microbial identification and antimicrobial susceptibility assessment).

Don’t know IVDR yet?

The new IVDR 2017/746 regulates access to the European market by classifying products into four risk classes, according to the patient and public health risks. To ensure that a product can be marketed within the EU, a Notified Body – TÜV SUD in our case – must evaluate the necessary Quality System and Technical documentation to certify that “the manufacturer has established, documented and implemented a quality management system compliant with IVDR.”

510(k) FDA clearance for Colibrí: obtained!

It’s a very exciting time overseas as well: our sample preparator Colibrí™ got its second 510(k) FDA clearance! After last December’s clearance for the preparation of ID MALDI-TOF targets, now its triple vision system, accurate pipettor, and user-friendly interface became available in the US for the preparation of microbial suspension for Antimicrobial Susceptibility Testing with bioMérieux VITEK 2.

What’s next?

Of course, our regulatory activity is not over! As international guidelines keep evolving, we constantly work to make all our products compliant with the latest regulations. Explore below our products & certificates!

Automated Disk Diffusion AST: the next step in full laboratory automation

Fully Automated EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) from Positive Blood Cultures: Diagnostic Accuracy and Implementation

At the end of September, the Journal of Clinical Microbiology published a remarkable study evaluating the accuracy and robustness of fully automated Rapid Antimicrobial Susceptibility Testing (RAST) directly from positive blood cultures (BCs). This paper – by A. Chekraoui and colleagues – will significantly impact the whole microbiology community, as the spread of multidrug-resistant organisms and the increase of resistant infections make RAST more valuable than ever. Let’s see what it’s all about!

Background

Although many positive BCs’ RAST methods have been released and rapid standardized disk-diffusion methods have been developed by EUCAST to enable susceptibility reports within 4 to 8 h and 16 to 18 h from positive BCs, the labor-intensive manual setup and the strictly defined reading time points have hampered their large-scale use in clinical microbiology laboratories. Nevertheless, shorter times for delivering accurate antimicrobial susceptibility results to provide patients with a rapid antimicrobial treatment remain one of the primary objectives to be achieved by microbiologists.

Here is where lab automation comes to help. In recent years, full laboratory automation has permitted the flexible, cost-effective, and accurate disk-diffusion method to return to the center stage and strengthen its position among other AST methods currently used in clinical microbiology laboratories.