A Cost-Effective Method for Identifying Enterobacterales with OXA-181

Area of Science:

• Microbiology
• Molecular Biology
• Infectious Diseases

Background:

• OXA-181 is a prevalent carbapenemase, particularly in the Indian subcontinent, often spreading to non-endemic regions.
• Distinguishing OXA-181 from similar enzymes typically requires costly and time-consuming sequencing.
• Effective surveillance requires rapid and accurate detection methods for OXA-181.

Purpose of the Study:

• To validate a specific Polymerase Chain Reaction (PCR) assay, OXA181PCR, for the accurate detection of the blaOXA-181 gene.
• To assess the prevalence and global distribution of OXA-181 producing Enterobacterales using the developed PCR method.
• To evaluate the utility of OXA181PCR in molecular surveillance programs.

Main Methods:

• Validation of OXA181PCR using a global collection of 315 bacteria with characterized carbapenemases.
• Application of OXA181PCR to 160 Enterobacterales isolates from the 2015 INFORM surveillance program.
• Comparison of OXA181PCR performance with a loop-mediated isothermal amplification (LAMP)-OXA48 assay.

Main Results:

• OXA181PCR demonstrated 100% sensitivity and specificity for detecting OXA-181.
• The assay identified OXA-181 in 36% (58/160) of Enterobacterales from the INFORM surveillance program.
• OXA-181 positive isolates were found in 9 countries across 5 continents, indicating widespread dissemination.

Conclusions:

• OXA181PCR is a highly sensitive and specific molecular tool for detecting OXA-181.
• The method facilitates accurate and efficient surveillance of OXA-181 producing bacteria globally.
• Incorporating OXA181PCR into surveillance programs can provide crucial data on the prevalence and spread of this important carbapenemase.