Ceftazidime-avibactam tolerance and persistence among difficult-to-treat KPC-producing Klebsiella pneumoniae clinical isolates from bloodstream infections

N Abichabki; G G Gaspar; L R Bortolato; D A F S Lima; L N Silva; R H C Pocente; J C Ferreira; T C Ogasawara; D Pereira; R R Guerra; C Wilhelm; P Barth; A F Martins; A Barth; G U L Braga; E C P De Martinis; J Bengtsson-Palme; F Bellissimo-Rodrigues; V R Bollela; A L C Darini; L N Andrade

doi:10.1007/s10096-024-05005-4

Ceftazidime-avibactam tolerance and persistence among difficult-to-treat KPC-producing Klebsiella pneumoniae clinical isolates from bloodstream infections

Eur J Clin Microbiol Infect Dis. 2024 Nov 30. doi: 10.1007/s10096-024-05005-4. Online ahead of print.

Authors

N Abichabki¹, G G Gaspar^{2

3}, L R Bortolato¹, D A F S Lima³, L N Silva³, R H C Pocente³, J C Ferreira¹, T C Ogasawara¹, D Pereira⁴, R R Guerra⁴, C Wilhelm⁴, P Barth⁴, A F Martins⁴, A Barth⁴, G U L Braga¹, E C P De Martinis¹, J Bengtsson-Palme^{5

6

7}, F Bellissimo-Rodrigues², V R Bollela^{2

3}, A L C Darini¹, L N Andrade⁸

Affiliations

¹ Faculdade de Ciências Farmacêuticas de Ribeirão Preto - Universidade de São Paulo, Ribeirão Preto, Brazil.
² Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo, Ribeirão Preto, Brazil.
³ Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo, Ribeirão Preto, Brazil.
⁴ Hospital de Clínicas de Porto Alegre - Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
⁵ Division of Systems and Synthetic Biology, Department of Life Sciences, SciLifeLab, Chalmers University of Technology, Gothenburg, Sweden.
⁶ Centre for Antibiotic Resistance Research (CARe) in Gothenburg, Gothenburg, Sweden.
⁷ Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
⁸ Faculdade de Ciências Farmacêuticas de Ribeirão Preto - Universidade de São Paulo, Ribeirão Preto, Brazil. leonardo@fcfrp.usp.br.

PMID: 39614972
DOI: 10.1007/s10096-024-05005-4

Abstract

Purpose: Tolerance and persistence occur "silently" in bacteria categorized as susceptible by antimicrobial susceptibility testing in clinical microbiology laboratories. They are different from resistance phenomena, not well-studied, and often remain unnoticeable. We aimed to investigate and characterize ceftazidime-avibactam (CZA) tolerance/persistence in 80 Klebsiella pneumoniae isolates from bloodstream infections.

Methods: We used the Tolerance Disk Test (TDtest) to detect CZA tolerance/persistence and investigate the avibactam (AVI) influence on them, and time-kill assays with minimal duration for killing (MDK) determination to characterize/differentiate CZA tolerance from persistence, for selected isolates. Whole genome sequencing was performed for 49/80 selected isolates to investigate genes related to beta-lactam tolerance/persistence and resistance as well as phylogeny studies.

Results: Tolerance/persistence to CZA was detected in 48/80 (60%) isolates, all extensively drug-resistant (XDR) or multidrug-resistant, carbapenem-resistant K. pneumoniae (CRKp), KPC producers, and previously categorized as susceptible (not resistant) to CZA. No heteroresistance was detected. CZA tolerance/persistence occurred due to ceftazidime tolerance/persistence and was not related to AVI in the CZA combination. 5/11 isolates were characterized as CZA-tolerant and 5/11 as CZA-persistent. The single (1/11) XDR and CRKp non-KPC producer was truly susceptible. All the CZA-tolerant/persistent isolates (ST11, ST258, ST340, ST437, ST16, ST17, and ST307) harbored the carbapenemase-encoding gene bla_KPC-2. Mutation in only two genes (rpoS and degQ) related to beta-lactam tolerance/persistence was found in only 7/49 CZA-tolerant/persistent isolates, suggesting the presence of yet unknown beta-lactam tolerance/persistence genes.

Conclusion: Among the K. pneumoniae bloodstream isolates studied, 60%, previously categorized as susceptible to CZA, were, actually, tolerant/persistent to this antibiotic, all these KPC producers.

Keywords: Antibiotic resistant bacteria; Minimal duration for killing (MDK); Time-kill assays; Tolerance disk test (TDtest).

Abstract

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