Molecular characterization of blaIMP-5, a new integron-borne metallo-β-lactamase gene from an Acinetobacter baumannii nosocomial isolate in Portugal

• Published in: FEMS microbiology letters Vol. 215; no. 1; pp. 33 - 39
• Main Authors: Da Silva, Gabriela J., Correia, Mário, Vital, Clementina, Ribeiro, Graça, Sousa, João C., Leitão, Rui, Peixe, Luı́sa, Duarte, Aida
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 24.09.2002; Blackwell
• Subjects: Acinetobacter baumannii; Bacteriology; Biological and medical sciences; Class 1 integron; Fundamental and applied biological sciences. Psychology; Genetics; Imipenem resistance; Metallo-β-lactamase; Microbiology; Portugal; Europe; Metallo-β-lactamase; Class 1 integron; Acinetobacter baumannii; Imipenem resistance; Human; Nosocomial infection; Enzyme; Neisseriaceae; β-Lactamase; Infection; Resistance; Antibiotic; Carbapenem derivatives; Gene; Integron; Bacteriosis; Molecular epidemiology; Bacteria; Hydrolases; Micrococcales; Clinical isolate; Imipenem; Class I integron
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1016/S0378-1097(02)00896-0

Acinetobacter baumannii 65FFC, an imipenem-resistant clinical strain, isolated from the urine of a patient at the Coimbra University Hospital, Portugal, in 1998, produced a metallo-β-lactamase with a calculated pI 9.3. The isolate was highly resistant to penicillins, broad-spectrum cephalosporins, including ceftazidime, ceftriaxone, cefepime, cefpirome, and to aztreonam, but it remained susceptible to ampicillin/sulbactam, aminoglycosides and quinolones. Nucleotide sequence revealed a new allelic variant of other bla IMP genes, named bla IMP-5. IMP-5 β-lactamase showed a greater homology with IMP-1, IMP-3 and IMP-4 (identified in Southeast Asia), than with IMP-2, found in Italy (93%, 92%, 91% and 87% of amino acid identity, respectively). bla IMP-5 was the only gene cassette inserted into a class 1 integron, named In76. This is the first IMP-enzyme reported in Portugal and the second in Europe, indicating a wider dissemination in the environment of bla IMP alleles.