title: Diversity of CTX-M beta-lactamases and their promoter regions from Enterobacteriaceae isolated in three Parisian hospitals.
abstract: Nine clinical isolates of Enterobacteriaceae (six Escherichia coli and three Proteus mirabilis) isolated in three Parisian hospitals between 1989 and 2000 showed a particular extended-spectrum cephalosporin-resistance profile characterized by resistance to cefotaxime and aztreonam but not to ceftazidime. CTX-M-1, CTX-M-2, CTX-M-9, CTX-M-14 and two novel plasmid-mediated CTX-M beta-lactamases (CTX-M-20, and CTX-M-21) were identified by polymerase chain reaction and isoelectric focusing (pI>8) and were associated in eight cases with TEM-1 (pI=5.4) or TEM-2 (pI=5.6) beta-lactamases. We used internal ISEcp1 and IS26 forward primers and the CTX-M consensus reverse primer to characterize the CTX-M beta-lactamase promoter regions and showed their high degree of structure diversity. We found upstream of some bla(CTX-M) genes, a 266-bp sequence 100% identical to the sequence upstream of the Kluyvera ascorbata beta-lactamase gene, suggesting that this chromosomal enzyme is the progenitor of the CTX-M-2/5 cluster.
authors: Service de Bactériologie, Hôpital Tenon, U.F.R Saint-Antoine, 4 rue de la Chine, 75970 Paris Cedex 20, France.
authors: Michèle
authors: M
authors: Saladin
authors: Van Thi Bao
authors: VT
authors: Cao
authors: Thierry
authors: T
authors: Lambert
authors: Jean-Luc
authors: JL
authors: Donay
authors: Jean-Louis
authors: JL
authors: Herrmann
authors: Zahia
authors: Z
authors: Ould-Hocine
authors: Charlotte
authors: C
authors: Verdet
authors: Françoise
authors: F
authors: Delisle
authors: Alain
authors: A
authors: Philippon
authors: Guillaume
authors: G
authors: Arlet
mesh_terms: D001483:Base Sequence; D018550:Cephalosporin Resistance / Q000235:genetics*; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D014644:Genetic Variation; D006761:Hospitals; D006801:Humans; D008969:Molecular Sequence Data; D010297:Paris; D010957:Plasmids; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011513:Proteus mirabilis / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; C412613:CTX-M-9 protein, E coli; C071167:beta-lactamase CTX-2; C456080:beta-lactamase CTX-M-14; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases