Objective:

To investigate the spread of multidrug-resistant Klebsiella pneumoniae in community settings across the United States.

Approach:

• Study Design: A nationwide genomic study analyzing over 2,000 antibiotic-resistant Klebsiella isolates from 10 regional diagnostic laboratories.
• Sample Collection: Isolates were collected from 42 states primarily from outpatients between July 2023 and July 2024.
• Resistance Testing: Isolates were tested against four commonly prescribed oral antibiotics and assessed for resistance mechanisms.
• Genomic Analysis: Analysis focused on the blaCTX-M-15 gene linked to extended-spectrum β-lactamase (ESBL) production.

Key Findings:

• Most isolates were from urinary tract infections (UTIs), predominantly affecting older adults and women.
• Nearly 70% of isolates were resistant to all four tested oral antibiotics.
• Resistance to carbapenems was present in a subset of isolates.
• The blaCTX-M-15 gene was frequently found on mobile plasmids, facilitating resistance spread.
• More than half of the isolates belonged to genetic clusters indicating recent transmission across multiple states.

Interpretation:

Multidrug-resistant Klebsiella pneumoniae is becoming established in community settings.

Limitations:

• The study did not include antibiotic-susceptible comparison isolates.
• Lacked detailed patient information.

Conclusion:

Continued genomic surveillance is essential for understanding and addressing the spread of multidrug-resistant Klebsiella pneumoniae.

Sources:

• Nature Communications