title: Highly drug-resistant Salmonella enterica serotype Kentucky ST198-X1: a microbiological study.
abstract: BACKGROUND
  Salmonella enterica is a major global food-borne pathogen, causing life-threatening infections. Ciprofloxacin and extended-spectrum cephalosporins (ESCs) are the drugs of choice for severe infections. We previously reported a ciprofloxacin-resistant S. enterica serotype Kentucky (S Kentucky) ST198-X1 strain that emerged in Egypt and spread throughout Africa and the Middle East from 2002 to 2008. We aimed to monitor recent trends in the location of transmission and antimicrobial resistance of this strain.
  
  
  METHODS
  We analysed isolates of S Kentucky collected by the French national surveillance system for salmonellosis in France from Jan 1, 2000, to Dec 31, 2011, and at two sites in Casablanca, Morocco, between Jan 1, 2003, and Dec 31, 2011. We analysed patterns of travel of patients infected with a ciprofloxacin-resistant strain of S Kentucky. We identified isolates showing resistance to ESCs or decreased susceptibility to carbapenems, characterised isolates by XbaI-pulsed field gel electrophoresis and multilocus sequence typing, and assessed mechanisms of bacterial resistance to antimicrobial drugs.
  
  
  RESULTS
  954 (1%) of 128,836 serotyped Salmonella spp isolates in France were identified as S Kentucky, as were 30 (13%) of 226 Salmonella spp isolates from Morocco. During 2000-08, 200 (40%) of 497 subculturable isolates of S Kentucky obtained in France were resistant to ciprofloxacin, compared with 376 (83%) of 455 isolates in 2009-11, suggesting a recent increase in ciprofloxacin resistance in France. Travel histories suggested S Kentucky infections originated predominantly in east Africa, north Africa, west Africa, and the Middle East, but also arose in India. We report several occurrences of acquisition of extended-spectrum β-lactamase (CTX-M-1, CTX-M-15), plasmid-encoded cephalosporinase (CMY-2), or carbapenemase (OXA-48, VIM-2) genes by ciprofloxacin-resistant isolates of S Kentucky ST198-X1 from the Mediterranean area since 2009. Many of these highly drug-resistant isolates were also resistant to most aminoglycosides, to co-trimoxazole (trimethoprim-sulfamethoxazole), and to azithromycin.
  
  
  CONCLUSIONS
  The potential risk to public health posed by ciprofloxacin-resistant S Kentucky ST198-X1 warrants its inclusion in national programmes for the control of S. enterica in food-producing animals, in particular in poultry.
  
  
  BACKGROUND
  Institut Pasteur, Institut de Veille Sanitaire, Fondation pour la Recherche Médicale, French Government Investissement d'Avenir programme.
authors.affiliation: Institut Pasteur, Unité des Bactéries Pathogènes Entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, Paris, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Le Hello
authors.forename: Dorothée
authors.initials: D
authors.lastname: Harrois
authors.forename: Brahim
authors.initials: B
authors.lastname: Bouchrif
authors.forename: Lucile
authors.initials: L
authors.lastname: Sontag
authors.forename: Dalèle
authors.initials: D
authors.lastname: Elhani
authors.forename: Véronique
authors.initials: V
authors.lastname: Guibert
authors.forename: Khalid
authors.initials: K
authors.lastname: Zerouali
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Weill
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D017963:Azithromycin; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002939:Ciprofloxacin; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009018:Morocco / Q000453:epidemiology; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology*; D019779:Salmonella enterica / Q000235:genetics; D014195:Travel; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002939:Ciprofloxacin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D017963:Azithromycin; C103022:beta-lactamase CMY-2; C473109:beta-lactamase CTX-M-15; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases; C063912:carbapenemase