Characterization of a novel plasmid-mediated cephalosporinase (CMY-9) and its genetic environment in an Escherichia coli clinical isolate.

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Citation

Doi Y, Shibata N, Shibayama K, Kamachi K, Kurokawa H, Yokoyama K, Yagi T, Arakawa Y

Characterization of a novel plasmid-mediated cephalosporinase (CMY-9) and its genetic environment in an Escherichia coli clinical isolate.

Antimicrob Agents Chemother. 2002 Aug;46(8):2427-34.

PubMed ID
12121914 [ View in PubMed
]
Abstract

An Escherichia coli strain, HKYM68, which showed resistance to broad-spectrum cephalosporins was isolated from a sputum specimen in Japan. The high-level resistance of the strain to ceftazidime, cefpirome, and moxalactam was carried by a self-transferable plasmid. The beta-lactamase gene responsible for the resistance was cloned and sequenced. The deduced amino acid sequence of this gene product, CMY-9, had a single amino acid substitution (E85D), the residue reported to be part of the recognition site for the R1 side chain of beta-lactams, compared with the amino acid sequence of CMY-8 and also had 78% identity with the amino acid sequence of CepH, a chromosomal cephalosporinase of Aeromonas hydrophila. A sul1-type class 1 integron containing an aacA1-orfG gene cassette was identified upstream of bla(CMY-9) and ended with a truncated 3' conserved segment. The following 2.1 kb was almost identical to the common region of integrons In6 and In7 and the integron of pSAL-1, except that orf513 encoding a putative transposase was identified instead of orf341 due to addition of a single nucleotide. bla(CMY-9) was closely located downstream of the end of the common region. These observations are indicative of the exogenous derivation of bla(CMY-9) from some environmental microorganisms such as aeromonads.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Dihydropteroate synthase type-1P0C002Details