Artículo
New carbenicillin-hydrolyzing beta-lactamase (CARB-7) from Vibrio cholerae non-O1, non-O139 strains encoded by the VCR region of the V. cholerae genome
Registro en:
1098-6596
10.1128/aac.46.7.2162-2168.2002
Autor
Melano, Roberto
Petroni, Alejandro
Garutti, Alicia
Saka, Héctor A.
Mange, Laura
Pasteran, Fernando
Rapoport, Melina J.
Rossi, Alicia
Galas, Marcelo F.
Resumen
Fil: Melano, Roberto. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Petroni, Alejandro. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Garutti, Alicia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Saka, Héctor Alex. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Mange, Laura. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Pasteran, Fernando. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Rapoport, Melina J. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Rossi, Alicia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. Fil: Galas, Marcelo F. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio de Antimicrobianos; Argentina. In a previous study, an analysis of 77 ampicillin-nonsusceptible (resistant plus intermediate categories) strains of Vibrio cholerae non-O1, non-O139, isolated from aquatic environment and diarrheal stool, showed that all of them produced a -lactamase with a pI of 5.4. Hybridization or amplification by PCR with a probe for blaTEM or primers for blaCARB gene families was negative. In this work, an environmental ampicillinresistant strain from this sample, ME11762, isolated from a waterway in the west region of Argentina, was studied. The nucleotide sequence of the structural gene of the -lactamase was determined by bidirectional sequencing of a Sau3AI fragment belonging to this isolate. The gene encodes a new 288-amino-acid protein, designated CARB-7, that shares 88.5% homology with the CARB-6 enzyme; an overall 83.2% homology with PSE-4, PSE-1, CARB-3, and the Proteus mirabilis N29 enzymes; and 79% homology with CARB-4 enzyme. The gene for this -lactamase could not be transferred to Escherichia coli by conjugation. The nucleotide sequence of the flanking regions of the blaCARB-7 gene showed the occurrence of three 123-bp V. cholerae repeated sequences, all of which were found outside the predicted open reading frame. The upstream fragment of the blaCARB-7 gene shared 93% identity with a locus situated inside V. cholerae’s chromosome 2. These results strongly suggest the chromosomal location of the blaCARB-7 gene, making this the first communication of a -lactamase gene located on the VCR island of the V. cholerae genome.