Sequence of conjugative plasmid pIP1206 mediating resistance to aminoglycosides by 16S rRNA methylation and to hydrophilic fluoroquinolones by efflux.
Self-transferable IncFI plasmid pIP1206, isolated from an Escherichia coli clinical isolate, carries two new resistance determinants: qepA, which confers resistance to hydrophylic fluoroquinolones by efflux, and rmtB, which specifies a 16S rRNA methylase conferring high-level aminoglycoside resistance. Analysis of the 168,113-bp sequence (51% G+C) revealed that pIP1206 was composed of several subregions separated by copies of insertion sequences. Of 151 open reading frames, 56 (37%) were also present in pRSB107, isolated from a bacterium in a sewage treatment plant. pIP1206 contained four replication regions (RepFIA, RepFIB, and two partial RepFII regions) and a transfer region 91% identical with that of pAPEC-O1-ColBM, a plasmid isolated from an avian pathogenic E. coli. A putative oriT region was found upstream from the transfer region. The antibiotic resistance genes tet(A), catA1, bla(TEM-1), rmtB, and qepA were clustered in a 33.5-kb fragment delineated by two IS26 elements that also carried a class 1 integron, including the sulI, qacEDelta1, aad4, and dfrA17 genes and Tn10, Tn21, and Tn3-like transposons. The plasmid also possessed a raffinose operon, an arginine deiminase pathway, a putative iron acquisition gene cluster, an S-methylmethionine metabolism operon, two virulence-associated genes, and a type I DNA restriction-modification (R-M) system. Three toxin/antitoxin systems and the R-M system ensured stabilization of the plasmid in the host bacteria. These data suggest that the mosaic structure of pIP1206 could have resulted from recombination between pRSB107 and a pAPEC-O1-ColBM-like plasmid, combined with structural rearrangements associated with acquisition of additional DNA by recombination and of mobile genetic elements by transposition.
Périchon
Bruno
B
Unité des Agents Antibactériens, Institut Pasteur, Paris, France.
Bogaerts
Pierre
P
Lambert
Thierry
T
Frangeul
Lionel
L
Courvalin
Patrice
P
Galimand
Marc
M
D000150:Acinetobacter / Q000187:drug effects / Q000235:genetics; D000617:Aminoglycosides / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001482:Base Composition; D001483:Base Sequence; D002874:Chromosome Mapping; D003227:Conjugation, Genetic; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D024841:Fluoroquinolones / Q000494:pharmacology; D005798:Genes, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics; D011815:R Factors / Q000235:genetics*; D012323:RNA Processing, Post-Transcriptional; D012329:RNA, Bacterial / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D018741:Replication Origin; D012689:Sequence Homology, Nucleic Acid
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D017931:DNA Primers; D004269:DNA, Bacterial; D024841:Fluoroquinolones; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S