Structural and Biochemical Features of OXA-517: a Carbapenem and Expanded-Spectrum Cephalosporin Hydrolyzing OXA-48 Variant.
Antimicrob Agents Chemother
; 67(2): e0109522, 2023 02 16.
Article
em En
| MEDLINE
| ID: mdl-36648230
ABSTRACT
OXA-48-producing Enterobacterales have now widely disseminated throughout the world. Several variants have now been reported, differing by just a few amino-acid substitutions or deletions, mostly in the region of the loop ß5-ß6. As OXA-48 hydrolyzes carbapenems but lacks significant expanded-spectrum cephalosporin (ESC) hydrolytic activity, ESCs were suggested as a therapeutic option. Here, we have characterized OXA-517, a natural variant of OXA-48- with an Arg214Lys substitution and a deletion of Ile215 and Glu216 in the ß5-ß6 loop, capable of hydrolyzing at the same time ESC and carbapenems. MICs values of E. coli expressing blaOXA-517 gene revealed reduced susceptibility to carbapenems (similarly to OXA-48) and resistance to ESCs. Steady-state kinetic parameters revealed high catalytic efficiencies for ESCs and carbapenems. The blaOXA-517 gene was located on a ca. 31-kb plasmid identical to the prototypical IncL blaOXA-48-carrying plasmid except for an IS1R-mediated deletion of 30.7-kb in the tra operon. The crystal structure of OXA-517, determined to 1.86 Å resolution, revealed an expanded active site compared to that of OXA-48, which allows for accommodation of the bulky ceftazidime substrate. Our work illustrates the remarkable propensity of OXA-48-like carbapenemases to evolve through mutation/deletion in the ß5-ß6 loop to extend its hydrolysis profile to encompass most ß-lactam substrates.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Contexto em Saúde:
3_ND
Problema de saúde:
3_neglected_diseases
/
3_zoonosis
Assunto principal:
Carbapenêmicos
/
Cefalosporinas
Idioma:
En
Revista:
Antimicrob Agents Chemother
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
França