title: [CMY-2-type plasmid-mediated AmpC ß-lactamases emerging in Tucumán, Argentina].
abstract: In the last years, Enterobacteriaceae such as Klebsiella pneumoniae, Proteus mirabilis and Escherichia coli, have acquired resistance to third-generation cephalosporins (C3G) because of the presence of plasmid-mediated AmpC ß-lactamases. The aim of this work was to detect plasmid AmpC enzymes and to investigate the predominant types in our region. Between March and July 2009, 733 consecutive isolates of Enterobacteriaceae derived from hospitals and outpatient centers were studied. Susceptibility testing was performed by disk diffusion; one P. mirabilis and three E. coli strains showed resistance to cephamycins (cefoxitin) and C3G. An E-test to determine MIC and a synergy test by aminophenylboronic disks were performed. Enzymatic activity against cefoxitin was confirmed by a microbiological assay. A polymerase chain reaction (PCR) for the detection of plasmid-mediated ampC genes of different groups was performed and a 462-bp amplicon was obtained when using primers directed against the CIT group; the obtained sequences were compared to blaCMY-2 sequences, showing 100% identity. The emergence of CMY-2-type plasmid-mediated AmpC ß-lactamases indicated the importance of implementing systematic monitoring of these resistances to avoid potential clinical and epidemiological consequences.
authors.affiliation: Instituto de Microbiología Dr. Luis C. Verna, Cátedra de Bacteriología, Facultad de Bioquímica, Química, Farmacia y Biotecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán. majure@fbqf.unt.edu.ar
authors.forename: María A
authors.initials: MA
authors.lastname: Jure
authors.forename: Constanza
authors.initials: C
authors.lastname: Presti
authors.forename: Norma M
authors.initials: NM
authors.lastname: Cudmani
authors.forename: Lidia M
authors.initials: LM
authors.lastname: Grellet
authors.forename: Carolina
authors.initials: C
authors.lastname: López
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: Musa
authors.forename: Olga C
authors.initials: OC
authors.lastname: Aulet
authors.forename: Carlos
authors.initials: C
authors.lastname: Nieto
authors.forename: Lucila
authors.initials: L
authors.lastname: Saavedra
authors.forename: Marta Cecilia
authors.initials: MC
authors.lastname: de Castillo
mesh_terms: D000595:Amino Acid Sequence; D001118:Argentina; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D002440:Cefoxitin / Q000494:pharmacology; D018550:Cephalosporin Resistance / Q000235:genetics; D002511:Cephalosporins / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D011512:Proteus Infections / Q000382:microbiology; D011513:Proteus mirabilis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D011815:R Factors / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014552:Urinary Tract Infections / Q000382:microbiology; D001618:beta-Lactamases / Q000032:analysis* / Q000737:chemistry / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002511:Cephalosporins; D004269:DNA, Bacterial; D002440:Cefoxitin; C103022:beta-lactamase CMY-2; C048795:AmpC beta-lactamases; D001618:beta-Lactamases