Affiliation:
1. Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
2. Department of Public Health, Sapienza University of Rome, Rome, Italy
3. Department of Molecular Medicine, Sapienza University of Rome, Rome, Laboratory affiliated to Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Italy
Abstract
The first reports of carbapenem-resistant
Enterobacterales
in our hospital date back to 2006. In that period, few ertapenem-resistant but meropenem-susceptible
Klebsiella pneumoniae
isolates belonging to sequence type (ST) 37 were retrieved from clinical samples. These strains produced the CTX-M-15 extended spectrum β-lactamase, OmpK35 was depleted due to a nonsense mutation, and a novel OmpK36 variant was identified. Yet, starting from 2010,
Klebsiella pneumoniae
carbapenemase (KPC)-producing ST512 isolates started prevailing and ST37 vanished from sight. Since 2018 the clinical use of the combination of ceftazidime–avibactam (CZA) has been introduced in clinical practice for the treatment of bacteria producing serine-β-lactamases, but KPC-producing, CZA-resistant
K. pneumoniae
are emerging. In 2021, four CZA-resistant ST37 isolates producing KPC variants were isolated from the same number of patients. blaKPC gene cloning in
Escherichia coli
was used to define the role of those KPC variants on CZA resistance, and whole genome sequencing was performed on these isolates and on three ST37 historical isolates from 2011. CZA resistance was due to mutations in the blaKPC genes carried on related pKpQIL-type plasmids, and three variants of the KPC enzyme have been identified in the four ST37 strains. The four ST37 isolates were closely related to each other and to the historical isolates, suggesting that ST37 survived without notice in our hospital for 10 years, waiting to re-emerge as a CZA-resistant
K. pneumoniae
clone. The ancestor of these contemporary isolates derives from ST37 wild-type porin strains, with no other mutations in chromosomal genes involved in conferring antibiotic resistance (parC, gyrA, ramR, mgrB, pmrB).
Funder
Sapienza Università di Roma
Istituto Pasteur-Fondazione Cenci Bolognetti
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献