A novel IncQ plasmid type harbouring a class 3 integron from Escherichia coli.
OBJECTIVE
To determine the genetic structures at the origin of the mobilization of the extended-spectrum beta-lactamase (ESBL) bla(GES-1) gene in an Escherichia coli clinical isolate.


METHODS
ESBL-encoding genes and class 1 or class 3 integron-specific motifs were screened. Conjugation experiments were performed to determine whether the plasmid-carrying bla(GES-1) gene was self-transferable. Plasmid sequencing was achieved by a primer-walking approach.


RESULTS
The bla(GES-1) gene was located in a class 3 integron. That unusual genetic structure was itself located on an approximately 9 kb plasmid, pQ7, which was not self-transferable. Sequence analysis revealed that plasmid pQ7 belonged to a novel subtype of the IncQ group.


CONCLUSIONS
This study identified for the first time the bla(GES-1) gene in E. coli and in Switzerland. It describes a novel IncQ-type plasmid subgroup that possesses original features, in particular iteron sequences that constitute a hot spot for integration of foreign DNA.
Service de Bactériologie-Virologie, INSERM U914 Emerging Resistance to Antibiotics, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine et Université Paris-Sud, K.-Bicêtre, France.
Laurent
L
Poirel
Alessandra
A
Carattoli
Sandrine
S
Bernabeu
Thomas
T
Bruderer
Reno
R
Frei
Patrice
P
Nordmann
D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D005798:Genes, Bacterial; D006801:Humans; D032023:Integrons; D008969:Molecular Sequence Data; D010957:Plasmids / Q000145:classification* / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D013557:Switzerland; D001618:beta-Lactamases / Q000235:genetics*
D001618:beta-Lactamases