title: Cefotaxime-hydrolysing beta lactamases in Morganella morganii.
abstract: The frequency of enterobacterial isolates with high resistance to expanded-spectrum beta-lactam antibiotics (mainly cefotaxime or ceftriaxone) has increased notoriously in Argentina, mainly because of the spread of extended-spectrum beta-lactamases. The aim of this work was the study of extended-spectrum beta-lactamases in several Morganella morganii isolates with unusually high resistance to ceftriaxone. These strains produced at least two beta-lactamases, of apparent pIs of 5.4 and 8.2, molecular weight 23 000, well inhibited by clavulanate, compatible with a broad-spectrum beta-lactamase - perhaps TEM-1 - and an extended-spectrum beta-lactamase, respectively. The extended-spectrum beta-lactamase was identified as a CTX-M-type beta-lactamase - probably CTX-M-2 - by polymerase chain reaction, restriction profile analysis and DNA-DNA hybridisation. The remaining isolates studied produced either the broad-spectrum beta-lactamase plus the ubiquitous AmpC beta-lactamase (13 strains), or the AmpC beta-lactamase only (10 strains).
authors.affiliation: Departamento de Microbiología, Immunología y Biotecnología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
authors.forename: P
authors.initials: P
authors.lastname: Power
authors.forename: M
authors.initials: M
authors.lastname: Radice
authors.forename: C
authors.initials: C
authors.lastname: Barberis
authors.forename: C
authors.initials: C
authors.lastname: de Mier
authors.forename: M
authors.initials: M
authors.lastname: Mollerach
authors.forename: M
authors.initials: M
authors.lastname: Maltagliatti
authors.forename: C
authors.initials: C
authors.lastname: Vay
authors.forename: A
authors.initials: A
authors.lastname: Famiglietti
authors.forename: G
authors.initials: G
authors.lastname: Gutkind
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002439:Cefotaxime / Q000378:metabolism*; D002511:Cephalosporins / Q000378:metabolism*; D006868:Hydrolysis; D008826:Microbial Sensitivity Tests; D020613:Morganella morganii / Q000187:drug effects / Q000201:enzymology*; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D001618:beta-Lactamases; D002439:Cefotaxime