Cloning and characterization of a 3-N-aminoglycoside acetyltransferase gene, aac(3)-Ib, from Pseudomonas aeruginosa.
A novel gene encoding an aminoglycoside 3-N-acetyltransferase, which confers resistance to gentamicin, astromicin, and sisomicin, was cloned from Pseudomonas aeruginosa Stone 130. Its sequence was determined and found to show considerable similarity to an aac(3)-I gene previously cloned from R plasmids from Enterobacter, Pseudomonas, and Serratia spp. We have designated the genes from the R plasmids and this work aac(3)-Ia and aac(3)-Ib, respectively. The two aac(3)-I genes share 74% nucleotide identity, and their deduced protein products are 88% similar. These data suggest that the genes derive from a common ancestor. Homology between the flanking sequences of both aac(3)-I genes and other resistance determinants known to reside in integron environments was also observed. Intragenic probes specific for either aac(3)-Ia or aac(3)-Ib were used in hybridization studies with a series of gentamicin-, astromicin-, and sisomicin-resistant clinical isolates. Of 59 clinical isolates tested, no isolates hybridized with both probes, 30 (51%) hybridized with the aac(3)-Ia probe, 12 (20%) hybridized with the aac(3)-Ib probe, and 17 (29%) did not hybridize with either probe. These data suggest the existence of at least one other aac(3)-I gene.
D000123:Acetyltransferases / Q000235:genetics*; D000595:Amino Acid Sequence; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D000123:Acetyltransferases; C045539:aminoglycoside N(3')-acetyltransferase