Carbapenemase-producing Enterobacterales in solid organ transplantation: Tip of the iceberg?

Area of Science:

• Microbiology
• Infectious Diseases
• Genomics

Background:

• A liver transplant recipient experienced a urinary tract infection (UTI) caused by Citrobacter freundii complex and Klebsiella aerogenes.
• Both bacterial species were found to produce dual carbapenemases, specifically KPC-3 and NDM-1, conferring resistance to a broad spectrum of antibiotics.

Discussion:

• Whole-genome sequencing revealed evidence of plasmid transfer between Citrobacter freundii and Klebsiella aerogenes within the patient.
• This horizontal gene transfer facilitated the dissemination of carbapenemase genes, contributing to the multidrug-resistant nature of the infection.
• The findings underscore the potential for silent plasmid transmission to drive the emergence and spread of carbapenem-resistant Enterobacteriaceae (CRE) in clinical settings.

Key Insights:

• Dual carbapenemase production (KPC-3/NDM-1) in common UTI pathogens like C. freundii and K. aerogenes presents a significant clinical challenge.
• Whole-genome sequencing is a powerful tool for elucidating the mechanisms of antimicrobial resistance gene dissemination, such as plasmid transfer.
• The study highlights the critical need for enhanced surveillance and infection control strategies to mitigate the threat of CRE.

Outlook:

• Implications for infection prevention protocols in immunocompromised patients, including liver transplant recipients.
• Recommendations for targeted screening strategies to detect carriers of carbapenemase-producing organisms.
• Emphasis on the importance of robust antimicrobial stewardship programs to preserve the efficacy of last-resort antibiotics.