Comparison of phenotypic tests for detecting BKC-1-producing Enterobacteriaceae isolates

Area of Science:

• Microbiology
• Clinical Diagnostics
• Antimicrobial Resistance

Background:

• Carbapenemase-producing Enterobacteriaceae (CPE) pose a significant threat due to resistance to last-resort antibiotics.
• Some CPE, particularly those with weak carbapenemases like BKC-1, can appear susceptible to carbapenems in standard laboratory tests.
• Accurate and timely detection of CPE is crucial for effective patient management and infection control.

Purpose of the Study:

• To assess the performance of various phenotypic methods in detecting Enterobacteriaceae isolates that produce the BKC-1 carbapenemase.
• To identify potential limitations of routine screening tests in identifying weak carbapenemase producers.

Main Methods:

• Evaluation of multiple established phenotypic methods for detecting carbapenemase activity.
• Testing against a panel of Enterobacteriaceae isolates confirmed to produce the BKC-1 carbapenemase.
• Comparison of results from different phenotypic tests to identify discrepancies.

Main Results:

• Certain phenotypic methods demonstrated reduced accuracy in detecting BKC-1 carbapenemase activity.
• Isolates producing BKC-1 carbapenemase were sometimes misclassified as susceptible to carbapenems by standard tests.
• Variability in performance was observed across the evaluated phenotypic methods.

Conclusions:

• Routine phenotypic screening tests may not reliably detect all carbapenemase-producing Enterobacteriaceae, especially weak producers like those with BKC-1.
• Further refinement or alternative methods may be necessary for accurate identification of BKC-1-producing Enterobacteriaceae in clinical laboratories.
• Improved diagnostic strategies are needed to combat the spread of carbapenem resistance.