OXA-Type β-Lactamases

Title:OXA-Type β-Lactamases

Volume: 5 Issue: 11

Author(s): Thierry Naas*Patrice Nordmann

Affiliation:

• Service de Bacteriologie-Virologie, Hopital de Bicetre, 94274 Le Kremlin-Bicetre, Assistance Publique-Hopitaux de Paris, Faculte de Medecine Paris-Sud, Universite Paris XI, France

Abstract: The OXA-type (oxacillin-hydrolysing) enzymes are widespread and have been mostly described in Enterobacteriaceae and in P. aeruginosa. They usually confer resistance to amino- and ureidopenicillin and possess high-level hydrolytic activity against cloxacillin, oxacillin, and methicillin. Their activities are weakly inhibited by clavulanic acid but sodium chloride (NaCl) possesses a strong il'lhibition activity. Oxacillin-hydrolysing -lactamases belong to Ambler class D and thus possess an active serine site as classes A and C β-lactamases. Overall amino-acid identities between class D and class A or class C β-lactamases is about 16%. Until now, 24 Ambler class D enzymes, named OXA-1 to OXA-22, AmpS and LCR-1, have been characterised, either by sequence and/or by biochemical analyses, but for none of them a three dimensional structure is yet available. While some oxacillinases present a significant degree of amino-acid identity (for example, OXA-l and OXA-4; OXA-10 (PSE-2) derivatives; OXA-2 and OXA- 3), most of them are only weakly related (20% to 30% amino-acid identity). Oxacillinases usually display a restricted-spectrum phenotype. However extension of their spectrum towards oxyimino cephalosporins and/or imipenem has recently been observed mostly as a consequence of point mutations in OXA-2 or OXA-10 derivatives. Their frequent plasmid- and/or integron-location provide them a mean for a wide diffusion.

Cite this article as:

Naas Thierry*, Nordmann Patrice, OXA-Type β-Lactamases, Current Pharmaceutical Design 1999; 5 (11) . https://dx.doi.org/10.2174/1381612805666230112185101