Changing molecular epidemiology and resistance patterns of carbapenem-resistant Klebsiella pneumoniae in California long-term acute care hospitals.

Authors

Kyle J Gontjes, Brendan J Kelly, Leigh Cressman, Anne Jaskowiak-Barr, Laurel Glaser, Laura L Cowden, Alexa Patel, Jennifer Han, Ellie J C Goldstein, Warren B Bilker, Evan S Snitkin, Ebbing Lautenbach

Published in

The Journal of infectious diseases. Aug 07, 2026. Epub Aug 07, 2026.

Abstract

The epidemiology of carbapenem-resistant Klebsiella pneumoniae (CRKP) must be monitored over time to understand resistance dynamics to existing and novel antibiotics.
Antibiotic susceptibility testing and whole-genome sequencing were performed on clinical CRKP isolates collected from the same California long-term acute care hospital network across two time periods: 2014-15 (period 1) and 2021-23 (period 2). Differences in sequence type (ST) diversity, carbapenem resistance-associated genotypes, and resistance to clinically important antibiotics were evaluated.
Eight hundred eighty-one isolates were collected (period 1, 374; period 2, 507). Study period 1's population was dominated by ST258 (94.1%). ST diversity markedly increased in period 2, with a reduced prevalence of ST258 (41.6%) and an increased abundance of other epidemic lineages: ST14 (27.4%), ST307 (6.9%), and ST17 (6.5%). Changes to circulating resistance genotypes and plasmids reflected the increased ST diversity. Increases in blaKPC-3-harboring isolates (66.0% vs. 76.1%) and non-carbapenemase-containing isolates (2.7% vs 12.6%) aligned with decreases in blaKPC-2-harboring isolates (30.5% vs. 6.3%). Statistically significant differences in resistance patterns were also observed between study periods, including colistin (35.0% vs. 20.2%), fosfomycin (27.0% vs. 13.4%), meropenem-vaborbactam (9.4% vs. 2.0%), and ceftazidime-avibactam (1.1% vs. 9.1%). Differential patterns of resistance emergence and spread across circulating STs largely drove resistance patterns in study period 2.
The comparison of clinical CRKP isolates collected from the same healthcare network and separated by nearly a decade revealed increasing ST diversity, mainly due to the introduction of numerous epidemic lineages, which coincided with differing patterns of circulating resistance-associated genotypes and antibiotic resistance.

PMID:
42566283
Bibliographic data and abstract were imported from PubMed on 08 Aug 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.