These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Molecular characterization of OXA-20, a novel class D beta-lactamase, and its integron from Pseudomonas aeruginosa.
    Author: Naas T, Sougakoff W, Casetta A, Nordmann P.
    Journal: Antimicrob Agents Chemother; 1998 Aug; 42(8):2074-83. PubMed ID: 9687410.
    Abstract:
    The Pseudomonas aeruginosa Mus clinical isolate produces OXA-18, a pI 5.5 class D extended-spectrum beta-lactamase totally inhibited by clavulanic acid (L. N. Philippon, T. Naas, A.-T. Bouthors, V. Barakett, and P. Nordmann, Antimicrob. Agents Chemother. 41:2188-2195, 1997). A second beta-lactamase was cloned, and the recombinant Escherichia coli clone pPL10 expressed a pI 7.4 beta-lactamase which conferred high levels of amoxicillin and ticarcillin resistance and which was partially inhibited by clavulanic acid. The 2.5-kb insert from pPL10 was sequenced, and a 266-amino-acid protein (OXA-20) was deduced; this protein has low amino acid identity with most of the class D beta-lactamases except OXA-2, OXA-15, and OXA-3 (75% amino acid identity with each). OXA-20 is a restricted-spectrum oxacillinase and is unusually inhibited by clavulanic acid. OXA-20 is a peculiar beta-lactamase because its translation initiates with a TTG (leucine) codon, which is rarely used as a translational origin in bacteria. Exploration of the genetic environment of oxa20 revealed the presence of the following integron features: (i) a second antibiotic resistance gene, aacA4; (ii) an intI1 gene; and (iii) two 59-base elements, each associated with either oxa20 or aacA4. This integron is peculiar because it lacks the 3' conserved region, and therefore is not a sul1-associated integron like most of them, and because its 3' end is located within tnpR, a gene involved in the transposition of Tn5393, a gram-negative transposon. P. aeruginosa Mus produces two novel and unrelated oxacillinases, OXA-18 and OXA-20, both of which are inhibited by clavulanic acid.
    [Abstract] [Full Text] [Related] [New Search]