A novel KPC-166 in ceftazidime/avibactam resistant ST307 Klebsiella pneumoniae causing an outbreak in intensive care COVID Unit, Italy
In: Journal of Microbiology, Immunology and Infection, Jg. 57 (2024), Heft 3, S. 457-469
Online
academicJournal
Zugriff:
Introduction: Aim of the study was the molecular characterization of 21 ceftazidime/avibactam resistant (CZA-R) Klebsiella pneumoniae strains, collected in the period October 2021–March 2022 from an Intensive Care COVID Unit in a Northern Italian Hospital. Methods: After growth on selective/chromogenic culture media and susceptibility tests assessment, resistance genes content was ascertained for all the isolates by the HybriSpot 12 multiplexing, PCR and Whole-Genome Sequencing (WGS). Clonality was assessed by PFGE and MLST according to the Pasteur scheme. A SNPs-based phylogenetic tree was obtained comparing representative isolates and global genomes. The blaKPC gene horizontal transmission was evaluated by conjugation experiments. blaKPC-166 was cloned in a pCR2.1 vector and transformed in chemically competent TOP10 cells. Results: Sixteen inpatients resulted positive for colonization and/or infection by KPC-producing K. pneumoniae (KPC-Kp) strains. The 21 CZA-R KPC-Kp isolates obtained showed MDR phenotype; susceptibility to meropenem was always retained. All the CZA-R KPC-Kp presented a novel blaKPC variant, named blaKPC-166, showing a single nucleotide substitution (T811C) compared to the blaKPC-94; but related to blaKPC-2. Two different pulsotypes were detected: A in 18/21 and B in 1/21 cases, two strains from the same patient being untypable by PFGE. Interestingly, the outbreak was sustained by the high-risk clone ST307, although the ST22, ST6342, ST6418 and ST6811 have also been identified and associated to KPC-166. Worryingly, blaKPC-166 could be transferred horizontally and, after cloning, it conferred resistance to CZA. Discussion: This novel variant confers CZA–resistance and carbapenems susceptibility restoration. As KPC-166 was found expressed by multiple Kp clones, greater efforts should be made to prevent the further dissemination of such strains in Italian clinical settings.
Titel: |
A novel KPC-166 in ceftazidime/avibactam resistant ST307 Klebsiella pneumoniae causing an outbreak in intensive care COVID Unit, Italy
|
---|---|
Autor/in / Beteiligte Person: | Piazza, Aurora ; Vittoria Mattioni Marchetti ; Bielli, Alessandra ; Gherard Batisti Biffignandi ; Piscopiello, Francesca ; Giudici, Riccardo ; Tartaglione, Livia ; Merli, Marco ; Vismara, Chiara ; Migliavacca, Roberta |
Link: | |
Zeitschrift: | Journal of Microbiology, Immunology and Infection, Jg. 57 (2024), Heft 3, S. 457-469 |
Veröffentlichung: | Elsevier, 2024 |
Medientyp: | academicJournal |
ISSN: | 1684-1182 (print) |
DOI: | 10.1016/j.jmii.2024.03.004 |
Schlagwort: |
|
Sonstiges: |
|