Affiliation:
1. Unité des Agents Antibactériens, Institut Pasteur, Paris, France
2. Cliniques Universitaires UCL de Mont-Godinne, Yvoir, Belgium
3. Centre d'Etudes Pharmaceutiques, Châtenay-Malabry, France
4. Plate-forme Intégration et Analyse Génomique, Institut Pasteur, Paris, France
Abstract
ABSTRACT
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 IS
26
elements that also carried a class 1 integron, including the
sulI, qacE
Δ
1, aad4
, and
dfrA17
genes and Tn
10
, Tn
21
, and Tn
3
-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.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology