Blood-Modified Carbapenem Inactivation Method: a Phenotypic Method for Detecting Carbapenemase-Producing...

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Carbapenemase-producing Enterobacteriaceae (CPE) pose a significant threat due to limited treatment options.
• Rapid detection of CPE is crucial for effective patient management and infection control.

Purpose of the Study:

• To develop and evaluate a novel method, Blood-mCIM, for direct detection of carbapenemase activity in positive blood cultures.
• To assess the diagnostic performance of Blood-mCIM compared to existing methods.

Main Methods:

• A modified carbapenem inactivation method (mCIM) was adapted for direct use with positive blood culture broths.
• The Blood-mCIM assay was tested on Bactec blood culture bottles inoculated with known CPE and non-CPE isolates.

Main Results:

• The Blood-mCIM assay demonstrated 100% sensitivity and 100% specificity.
• All blood cultures with CPE isolates tested positive, while all with non-CPE isolates tested negative.

Conclusions:

• Blood-mCIM is a highly accurate, inexpensive, and simple method for detecting carbapenemase activity directly from blood cultures.
• This assay can facilitate prompt antimicrobial therapy for CPE bloodstream infections and support surveillance efforts.