FDA approves Xpert Carba-R Assay to detect genetic markers for antibiotic-resistant bacteria

30 June 2016 (Last Updated June 30th, 2016 18:30)

The US Food and Drug Administration (FDA) has granted approval to market the Xpert Carba-R Assay, an infection control aid to detect genetic markers for carbapenem antibiotics-resistant bacteria.

The US Food and Drug Administration (FDA) has granted approval to market the Xpert Carba-R Assay, an infection control aid to detect genetic markers for carbapenem antibiotics-resistant bacteria.

Developed by US-based Cepheid , the Xpert Carba-R Assay is designed to curb infection and can be used with other clinical and laboratory findings.

Data from two clinical studies has prompted the FDA approval.

The first study used rectal swabs of 755 patients, which compared the results from the Xpert Carba-R Assay with that of reference cultures and automated real-time polymerase chain reaction (PCR) sequencing.

A second study evaluated the clinical performance of Xpert Carba-R Assay by testing 432 rectal swabs, which were artificially created with specific concentrations of bacteria containing the genes detected by the test.

"Hospitals can more quickly identify these dangerous bacteria resistant to certain antibiotics."

Results of both studies displayed similar functionalities of the Xpert Carba-R Assay and culture method.

The assay tests patient's specimens to identify markers for carbapenem-resistant Enterobacteriaceae (CRE).

Center for Devices and Radiological Health In Vitro Diagnostics and Radiological Health FDA office director Alberto Gutierrez said: "By using a specimen taken directly from a patient to test for the presence of genetic markers, hospitals can more quickly identify these dangerous bacteria resistant to certain antibiotics."

While the conventional tests take up to four days and involve an additional test to confirm the presence of carbapenem antibiotics inactivating enzyme, carbapenemase, the Xpert Carba-R Assay evaluates specimens derived directly from patients by rectal swabs.

It aims at detecting five different genetic markers associated with carbapenemase produced by CRE.

However, it is not functional in detecting the bacteria that creates carbapenemase and its associated activity or other possible non-enzymatic causes of carbapenem resistance. The Xpert Carba-R Assay detects only the genetic material.

It also does not detect all types of carbapenemase genes, while detection of bacteria is considered important for an accurate tracking of carbapenem resistance.

FDA has emphasised on continuing standard bacterial culture alongwith the Xpert Carba-R Assay.

In addition, the agency also stressed the need of concomitant cultures to recover organisms for epidemiological typing, antimicrobial susceptibility testing, and for confirmatory bacterial identification.