Molecular characterization of In50, a class 1 integron encoding the gene for the extended-spectrum beta-lactamase VEB-1 in Pseudomonas aeruginosa.
A clinical isolate of Pseudomonas aeruginosa, JES, was resistant to extended-spectrum cephalosporins with a marked synergistic effect with clavulanic acid on a routine antibiogram. Preliminary PCR analysis revealed the presence of blaVEB-1, an integron-located gene encoding an extended-spectrum beta-lactamase previously identified in Escherichia coli MG-1. Using class 1 integron primers and blaVEB-1 intragenic primers, the insert region of the blaVEB-1 containing integron along with some flanking sequence from P. aeruginosa JES was amplified and subsequently sequenced. In50 contains within its variable region, in addition to qacE delta 1 and sull genes commonly found in class 1 integrons, two gene cassettes, veb1 and aadB. In50 is peculiar since its attI1 site is interrupted by two novel insertion sequences, IS1999 and IS2000. P. aeruginosa JES and Escherichia coli MG-1 strains were isolated from patients previously hospitalized in south east Asian countries. The finding of blaVEB-1 in these strains and on different integrons underlines the interspecies spread of this integron-located extended-spectrum beta-lactamase gene.
Naas
T
T
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique-Hôpitaux de Paris, Faculté de Médecine Paris-Sud, France. thierry.naas@kb.u-psud.fr
Poirel
L
L
Karim
A
A
Nordmann
P
P
D000595:Amino Acid Sequence; D001483:Base Sequence; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D020071:Interspersed Repetitive Sequences; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics*
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C119424:beta-lactamase VEB-1, E coli; D001618:beta-Lactamases