CTX-M-1-related extended-spectrum beta-lactamases producing Escherichia coli: so far a sporadic event in Western Austria.
BACKGROUND
The present study was aimed to searching for CTX-M-type extended-spectrum beta-lactamases in community- and hospital-acquired Escherichia coli (E. coli) collected in western Austria and to investigate their clonal relatedness and their ability to spread.


METHODS
All patients with E. coli positive cultures collected from a catchment population of 186,000 between January and July 2006 were enrolled into the study. CTX-M-producing E. coli were identified by antibiotic susceptibility testing and blaCTX-M multiplex PCR. Clonal relatedness was analyzed by pulsed-field gel electrophoresis (PFGE).


RESULTS
In 2,042 E. coli isolates, 20 isolates (16 from urine, 4 from blood cultures) demonstrated CTX-M-1-related genes and no CTX-M-2- or CTX-M-9-related enzymes or CTX-M-15-producing strains were identified. We did not find clonal relatedness among CTX-M-1 producers isolated from the same referring center. E. coli were investigated for plasmid transfer ability of CTX-M-1-encoding genes. Plasmid digest patterns were not consistent with episomal spread of resistance loci. Transfection of CTX-M-encoding plasmids failed.


CONCLUSIONS
Our data suggest that the emergence of CTX-M-1-producing E. coli in western Austria may be attributed to multiple independent events.
Dept. of Pediatrics, Medical University Innsbruck, Anichstr. 35, A-6020, Innsbruck, Austria. Martina.Prelog@i-med.ac.at
M
M
Prelog
M
M
Fille
W
W
Prodinger
K
K
Grif
A
A
Brunner
R
R
Würzner
L B
LB
Zimmerhackl
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000494:pharmacology; D001317:Austria; D016470:Bacteremia / Q000382:microbiology; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010957:Plasmids / Q000235:genetics; D014552:Urinary Tract Infections / Q000382:microbiology; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
D000890:Anti-Infective Agents; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases