title: Utility of the ceftazidime-imipenem antagonism test (CIAT) to detect and confirm the presence of inducible AmpC beta-lactamases among enterobacteriaceae.
abstract: Detection of AmpC beta-lactamase production by enterobacteria has been problematic. Contrary to ESBLs, no specific guidelines are available for detection and confirmation of AmpC production by clinical relevant microorganisms. Moreover, some bacterial species may produce inducible AmpC beta-lactamases that can be easily overlooked by routine susceptibility tests. We reported here a new test based on the strong inducible effect of imipenem on AmpC genes and the consequent antagonism with ceftazidime. This test is very simple and proved to be helpful in detecting AmpC-inducible enzymes among several species of clinical isolates.
authors.affiliation: Microbiology sections, Weinmann Laboratório LTDA, Ramiro Barcelos 910, 90035-001 Porto Alegre, RS, Brazil. vcantarelli@weinmann.com.br
authors.forename: Vlademir Vicente
authors.initials: VV
authors.lastname: Cantarelli
authors.forename: Everton
authors.initials: E
authors.lastname: Inamine
authors.forename: Teresa Cristina Z
authors.initials: TC
authors.lastname: Brodt
authors.forename: Carina
authors.initials: C
authors.lastname: Secchi
authors.forename: Bianca C
authors.initials: BC
authors.lastname: Cavalcante
authors.forename: Fabiana de Souza
authors.initials: Fde S
authors.lastname: Pereira
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics; D002442:Ceftazidime / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D010641:Phenotype; D001618:beta-Lactamases / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015378:Imipenem; D002442:Ceftazidime; C048795:AmpC beta-lactamases; D001618:beta-Lactamases