Acquired metallo-β-lactamases (MBLs) are resistance determinants of increasing clinical importance in Gram-negative bacterial pathogens, which confer a broad-spectrum β-lactam resistance including carbapenems. Several such enzymes have been described since the 1990s. In this work a novel acquired MBL, named FIM-1, was identified and characterized. The bla(FIM-1) gene was cloned from a multidrug-resistant Pseudomonas aeruginosa clinical isolate (FI-14/157) cultured from a patient with a vascular graft infection in Florence, Italy. The isolate belonged in the sequence type 235 epidemic clonal lineage. The FIM-1 enzyme is a member of subclass B1 and, among acquired MBLs, exhibited the highest similarity (around 40% amino acid identity) with NDM-type enzymes. In P. aeruginosa FI-14/157 the bla(FIM-1) gene was apparently inserted into the chromosome and associated with ISCR19-like elements that were likely involved in the capture and mobilization of this MBL gene. Transfer experiments of the bla(FIM-1) gene to an Escherichia coli or another P. aeruginosa strain by conjugation or electrotransformation were not successful. The FIM-1 protein was produced in Escherichia coli and purified by two chromatography steps. Analysis of the kinetic parameters, carried out with the purified enzyme, revealed that FIM-1 has a broad substrate specificity, with preference for penicillins (except the 6α-methoxy derivative temocillin) and carbapenems. Aztreonam was not hydrolyzed. Detection of this novel type of acquired MBL in a P. aeruginosa clinical isolate underscores the increasing diversity of such enzymes that can be encountered in the clinical setting.
|Titolo:||FIM-1, a new acquired metallo-beta-lactamase from a Pseudomonas aeruginosa clinical isolate from Italy|
|Citazione:||Pollini, S., Maradei, S., Pecile, P., Olivo, G., Luzzaro, F., Docquier, J.D., et al. (2013). FIM-1, a new acquired metallo-beta-lactamase from a Pseudomonas aeruginosa clinical isolate from Italy. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 57(1), 410-416.|
|Appare nelle tipologie:||1.1 Articolo in rivista|
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