Ciprofloxacin-resistant, CTX-M-15-producing Escherichia coli ST131 clone in extraintestinal infections in Italy.
Quinolone and β-lactam resistance mechanisms and clonal relationships were characterized among Escherichia coli isolates resistant to ciprofloxacin and extended-spectrum cephalosporins associated with human extra-intestinal infections in Rome. The E. coli. ST131 clone was found to be prevalent. This clone invariably carried a specific pattern of substitutions in the topoisomerase genes and all isolates but one produced CTX-M-15. One ST131 isolate produced SHV-12. The new ST131 variant described here is of particular concern because it combines fluoroquinolone resistance and chromosomally encoded CTX-M-15.
Cerquetti
M
M
Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
Giufrè
M
M
García-Fernández
A
A
Accogli
M
M
Fortini
D
D
Luzzi
I
I
Carattoli
A
A
D019943:Amino Acid Substitution / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002939:Ciprofloxacin / Q000494:pharmacology*; D016000:Cluster Analysis; D027101:DNA Topoisomerase IV / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058889:Molecular Typing; D020125:Mutation, Missense; D012384:Rome / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases; D027101:DNA Topoisomerase IV