Diversity of CTX-M beta-lactamases and their promoter regions from Enterobacteriaceae isolated in three Parisian hospitals.
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.
Saladin
Michèle
M
Service de Bactériologie, Hôpital Tenon, U.F.R Saint-Antoine, 4 rue de la Chine, 75970 Paris Cedex 20, France.
Cao
Van Thi Bao
VT
Lambert
Thierry
T
Donay
Jean-Luc
JL
Herrmann
Jean-Louis
JL
Ould-Hocine
Zahia
Z
Verdet
Charlotte
C
Delisle
Françoise
F
Philippon
Alain
A
Arlet
Guillaume
G
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*
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