Clonal emergence of extended-spectrum beta-lactamase (CTX-M-2)-producing Salmonella enterica serovar Virchow isolates with reduced susceptibilities to ciprofloxacin among poultry and humans in Belgium and France (2000 to 2003).
Antibiotic treatment is not required in cases of Salmonella enterica gastroenteritis but is essential in cases of enteric fever or invasive salmonellosis or in immunocompromised patients. Although fluoroquinolones and extended-spectrum cephalosporins are the drugs of choice to treat invasive Salmonella, resistance to these antibiotics is increasing worldwide. During the period 2000 to 2003, 90 Salmonella enterica serovar Virchow poultry and poultry product isolates and 11 serovar Virchow human isolates were found to produce an extended-spectrum beta-lactamase, CTX-M-2, concomitantly with a TEM-1 beta-lactamase. The bla(CTX-M-2) gene was located on a large conjugative plasmid (>100 kb). Pulsed-field gel electrophoresis indicated a clonal relationship between the poultry and human isolates. All these isolates displayed additional resistance to trimethoprim-sulfamethoxazole and tetracycline as well as a reduced susceptibility to ciprofloxacin (MICs of between 0.5 and 1 mug/ml). CTX-M-2-producing Salmonella with a reduced susceptibility to fluoroquinolones constitutes a major concern, since such strains could disseminate on a large scale and jeopardize classical antibiotic therapy in immunocompromised patients.
Bertrand
Sophie
S
National Reference Centre for Salmonella and Shigella, Bacteriology Division, Scientific Institute of Public Health, 14 Wytsman Street, B-1050 Brussels, Belgium. sbertrand@iph.fgov.be
Weill
François-Xavier
FX
Cloeckaert
Axel
A
Vrints
Martine
M
Mairiaux
Eric
E
Praud
Karine
K
Dierick
Katlijne
K
Wildemauve
Christa
C
Godard
Claudine
C
Butaye
Patrick
P
Imberechts
Hein
H
Grimont
Patrick A D
PA
Collard
Jean-Marc
JM
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D015373:Bacterial Typing Techniques; D001530:Belgium; D002876:Chromosomes, Bacterial / Q000235:genetics; D002939:Ciprofloxacin / Q000494:pharmacology*; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005602:France; D016680:Genome, Bacterial / Q000235:genetics; D005838:Genotype; D006801:Humans; D008461:Meat Products / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D012150:Polymorphism, Restriction Fragment Length; D011200:Poultry; D011201:Poultry Diseases / Q000382:microbiology*; D012480:Salmonella Infections / Q000382:microbiology*; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D002939:Ciprofloxacin; C071167:beta-lactamase CTX-2; D001618:beta-Lactamases