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oai:repisalud.isciii.es:20.500.12105/265702025-12-18T13:01:31Zcom_20.500.12105_2052com_20.500.12105_2051com_20.500.12105_15322col_20.500.12105_19609col_20.500.12105_16967
Repisalud author Barceló, Isabel M author Escobar-Salom, Maria author Cabot, Gabriel author Perelló-Bauzà, Pau author Jordana-Lluch, Elena author Taltavull, Biel author Torrens, Gabriel author Rojo-Molinero, Estrella author Zamorano, Laura author Perez Gomez, Astrid author Oliver, Antonio author Juan, Carlos funder Govern de les Illes Balears (España) funder RETICS-Investigación en Patología Infecciosa (REIPI-ISCIII) (España) funder Instituto de Salud Carlos III funder Ministerio de Ciencia e Innovación (España) funder Unión Europea. Fondo Europeo de Desarrollo Regional (FEDER/ERDF) 2025-03-26T08:16:48Z 2025-03-26T08:16:48Z 2024-05-02 Barceló IM, Escobar-Salom M, Cabot G, Perelló-Bauzà P, Jordana-Lluch E, Taltavull B, Torrens G, Rojo-Molinero E, Zamorano L, Pérez A, Oliver A, Juan C. Transferable AmpCs in Klebsiella pneumoniae: interplay with peptidoglycan recycling, mechanisms of hyperproduction, and virulence implications. Antimicrob Agents Chemother. 2024 May 2;68(5):e0131523. 10.1128/aac.01315-23 1098-6596 0066-4804 Antimicrobial agents and chemotherapy 38517189 https://hdl.handle.net/20.500.12105/26570 Chromosomal and transferable AmpC β-lactamases represent top resistance mechanisms in different gram-negatives, but knowledge regarding the latter, mostly concerning regulation and virulence-related implications, is far from being complete. To fill this gap, we used Klebsiella pneumoniae (KP) and two different plasmid-encoded AmpCs [DHA-1 (AmpR regulator linked, inducible) and CMY-2 (constitutive)] as models to perform a study in which we show that blockade of peptidoglycan recycling through AmpG permease inactivation abolished DHA-1 inducibility but did not affect CMY-2 production and neither did it alter KP pathogenic behavior. Moreover, whereas regular production of both AmpC-type enzymes did not attenuate KP virulence, when blaDHA-1 was expressed in an ampG-defective mutant, Galleria mellonella killing was significantly (but not drastically) attenuated. Spontaneous DHA-1 hyperproducer mutants were readily obtained in vitro, showing slight or insignificant virulence attenuations together with high-level resistance to β-lactams only mildly affected by basal production (e.g., ceftazidime, ceftolozane/tazobactam). By analyzing diverse DHA-1-harboring clinical KP strains, we demonstrate that the natural selection of these hyperproducers is not exceptional (>10% of the collection), whereas mutational inactivation of the typical AmpC hyperproduction-related gene mpl was the most frequent underlying mechanism. The potential silent dissemination of this kind of strains, for which an important fitness cost-related contention barrier does not seem to exist, is envisaged as a neglected threat for most β-lactams effectiveness, including recently introduced combinations. Analyzing whether this phenomenon is applicable to other transferable β-lactamases and species as well as determining the levels of conferred resistance poses an essential topic to be addressed. IMPORTANCE: Although there is solid knowledge about the regulation of transferable and especially chromosomal AmpC β-lactamases in Enterobacterales, there are still gaps to fill, mainly related to regulatory mechanisms and virulence interplays of the former. This work addresses them using Klebsiella pneumoniae as model, delving into a barely explored conception: the acquisition of a plasmid-encoded inducible AmpC-type enzyme whose production can be increased through selection of chromosomal mutations, entailing dramatically increased resistance compared to basal expression but minor associated virulence costs. Accordingly, we demonstrate that clinical K. pneumoniae DHA-1 hyperproducer strains are not exceptional. Through this study, we warn for the first time that this phenomenon may be a neglected new threat for β-lactams effectiveness (including some recently introduced ones) silently spreading in the clinical context, not only in K. pneumoniae but potentially also in other pathogens. These facts must be carefully considered in order to design future resistance-preventive strategies. eng AmpR regulator Galleria mellonella Klebsiella pneumoniae blaCMY-2 blaDHA-1 Peptidoglycan recycling Transferable AmpC β-lactamases Virulence Transferable AmpCs in Klebsiella pneumoniae: interplay with peptidoglycan recycling, mechanisms of hyperproduction, and virulence implications research article 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 URL https://repisalud.isciii.es/bitstreams/2a7ec6b3-0a5a-45f1-8176-902934df084a/download File MD5 2fa91f7abd4f0d464d184d38b21382ea 875800 application/pdf TransferableAmpCs_KlebsiellaPneumoniae_2024.pdf URL https://repisalud.isciii.es/bitstreams/f6a61a41-e6c7-4a1f-b193-a830afb131ab/download File MD5 b02872378b3a57f0d696a63a92f43666 705587 application/pdf Supplementary_TransferableAmpCs_KlebsiellaPneumoniae_2024.pdf URL https://repisalud.isciii.es/bitstreams/2ea0d1fc-030a-47c0-8e7b-495b18b72bf6/download File MD5 d85f38782f061326566d765d6a3c09bf 103572 application/pdf Correction_TrainedImmunityRegulated_T_cell-induced_2024.pdf