Streck ARM-D Kits detect more antibiotic resistance than comparable tests

Streck, Inc., received great interest in Streck ARM-D® Kits after its poster presentation on improved methodology for detection of antibiotic resistance in Gram-negative bacteria at ECCMID 2018 in Madrid.

Streck Director of R&D New Product Development Chris Connelly, Ph.D., presented the poster.

Connelly's study showed the Streck ARM-D β-Lactamase Kits detect more antibiotic resistance determinants than comparable tests due to their design. "This highlights the need to have comprehensive panels for PCR-based molecular tests so antibiotic resistance does not go undetected," Connelly said.

Antibiotic-resistant bacteria can complicate treatment choice in healthcare settings, Connelly said. Many mechanisms contribute to antibiotic resistance but the most common are β-Lactamases. As a strategy to complement phenotypic testing, PCR-based assays are being used to correctly and comprehensively identify the presence or absence of the genes associated with antibiotic resistance.

PCR-based tests utilize extracted nucleic acid from a number of different sample matrices and must retain their sensitivity and specificity. To do so, the test should identify multiple genetic variants within a given resistance gene family. Additionally, these tests should include controls that mimic the patient sample, including the sample matrix, to verify the accuracy and precision of the entire analytical process. The data described in the poster demonstrates a direct comparison of multiple commercially available real-time PCR-based assays, complete with controls, in the evaluation of Gram-negative bacteria isolates for the presence of genes imparting antibiotic resistance.

The data presented support use of the Streck ARM-D Kits as comprehensive screening tools for β-Lactamase-based resistance. Kit performance was as good or better for comparable targets detected with the other commercial tests. In total, these data demonstrate the Streck ARM-D Kits provide a suitable tool for detection of antibiotic resistance given the broad number of targets identified by these kits.

Molecular controls, positive for each target, demonstrated the expected identification profile of organisms and resistance mechanisms using the Streck ARM-D Kits, ampC and β-Lactamase, BioFire FilmArray BCID, and Cepheid Xpert® Carba-R tests. Stability analysis demonstrated equivalent analytical performance when controls were held for up to 150 days at 4 °C.​​