title: Characterisation of CMY-4, an AmpC-type plasmid-mediated beta-lactamase in a Tunisian clinical isolate of Proteus mirabilis.
abstract: A strain of Proteus mirabilis resistant to beta-lactams, including cefoxitin, was isolated from the urine of a woman from Tunisia. Its antibiotic susceptibility pattern and that of the Escherichia coli transconjugant suggested the presence of an AmpC-type beta-lactamase. Two bands of beta-lactamase activity (pI 5.4 and 9.2) were detected by isoelectric focusing. The nucleotide sequence of the gene encoding the AmpC-type enzyme was determined. The deduced amino acid sequence was 98-99% identical to CMY-3 and to those of the plasmid-mediated AmpC-type beta-lactamases originated from Citrobacter freundii and 97% identical to the chromosome-encoded beta-lactamase of a Tunisian clinical isolate of C. freundii. This enzyme differs from CMY-2 by one substitution (Arg for Trp at position 221) and from CMY-3 by two substitutions (Glu for Gly at position 42 and Ser for Asn at position 363) and we propose the denomination CMY-4.
authors.affiliation: Service de Microbiologie, Université Paris VII Denis Diderot, Hôpital Saint-Louis, France.
authors.forename: C
authors.initials: C
authors.lastname: Verdet
authors.forename: G
authors.initials: G
authors.lastname: Arlet
authors.forename: S
authors.initials: S
authors.lastname: Ben Redjeb
authors.forename: A
authors.initials: A
authors.lastname: Ben Hassen
authors.forename: P H
authors.initials: PH
authors.lastname: Lagrange
authors.forename: A
authors.initials: A
authors.lastname: Philippon
mesh_terms: D000368:Aged; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002440:Cefoxitin / Q000494:pharmacology; D002513:Cephamycins / Q000494:pharmacology; D016971:Citrobacter freundii / Q000201:enzymology / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D011513:Proteus mirabilis / Q000187:drug effects / Q000201:enzymology*; D011815:R Factors / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002513:Cephamycins; D002440:Cefoxitin; D001618:beta-Lactamases