Characterization of Class 1 integrons from Pseudomonas aeruginosa that contain the bla(VIM-2) carbapenem-hydrolyzing beta-lactamase gene and of two novel aminoglycoside resistance gene cassettes.
Two clonally unrelated Pseudomonas aeruginosa clinical strains, RON-1 and RON-2, were isolated in 1997 and 1998 from patients hospitalized in a suburb of Paris, France. Both isolates expressed the class B carbapenem-hydrolyzing beta-lactamase VIM-2 previously identified in Marseilles in the French Riviera. In both isolates, the bla(VIM-2) cassette was part of a class 1 integron that also encoded aminoglycoside-modifying enzymes. In one case, two novel aminoglycoside resistance gene cassettes, aacA29a and aacA29b, were located at the 5' and 3' end of the bla(VIM-2) gene cassette, respectively. The aacA29a and aacA29b gene cassettes were fused upstream with a 101-bp part of the 5' end of the qacE cassette. The deduced amino acid sequence AAC(6')-29a protein shared 96% identity with AAC(6')-29b but only 34% identity with the aacA7-encoded AAC(6')-I1, the closest relative of the AAC(6')-I family enzymes. These aminoglycoside acetyltransferases had amino acid sequences much shorter (131 amino acids) than the other AAC(6')-I enzymes (144 to 153 amino acids). They conferred resistance to amikacin, isepamicin, kanamycin, and tobramycin but not to gentamicin, netilmicin, and sisomicin.
Poirel
L
L
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine Paris-Sud, 94275 Le Kremlin-Bicêtre, France.
Lambert
T
T
Türkoglü
S
S
Ronco
E
E
Gaillard
J
J
Nordmann
P
P
D000595:Amino Acid Sequence; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D015780:Carbapenems / Q000378:metabolism*; D003001:Cloning, Molecular; D003227:Conjugation, Genetic / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D018274:Electroporation; D005798:Genes, Bacterial / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D015780:Carbapenems; D004269:DNA, Bacterial; C425108:beta-lactamase bla(vim-2); D001618:beta-Lactamases