title: Emergence of multidrug-resistant Salmonella enterica serotype 4,[5],12:i:- involving human cases in Canada: results from the Canadian Integrated Program on Antimicrobial Resistance Surveillance (CIPARS), 2003-10.
abstract: OBJECTIVE
  Over the last decade, a marked increase in Salmonella enterica serotype 4,[5],12:i:- with a core resistance to ampicillin, streptomycin, sulphonamides and tetracycline (ASSuT) has been observed in Europe. This study describes the emergence and characterization of isolates of multidrug-resistant Salmonella 4,[5],12:i:- in Canada.
  
  
  METHODS
  Human clinical isolates of Salmonella 4,[5],12:i:- were identified by provincial laboratories from 2003 to 2010. Serotyping and phage typing were performed by standardized methodologies. MIC values were determined using broth microdilution. PCR was used to determine the presence of resistance genes. Multilocus sequence typing was performed on a selected number of isolates.
  
  
  RESULTS
  A total of 26 251 Salmonella were submitted as part of the Canadian Integrated Program on Antibiotic Resistance Surveillance (CIPARS). Of these, Salmonella 4,[5],12:i:- accounted for a total of 766 isolates (2.9%), and the number increased significantly from 42 (1.4%) in 2003 to 164 (4.8%) in 2010. The ASSuT+ phenotype was observed in 11.9% (n = 91) of Salmonella 4,[5],12:i:- isolates and increased from two isolates in 2003 to 35 isolates in 2010. Two sequence types (STs) were observed. ST34 was mainly associated with the ASSuT isolates (n = 24; 38%), which contained blaTEM, strA-strB, tet(B) and sul2. ST19 was more likely to be associated with the ACSSuT phenotype and contained blaTEM, floR, strA-strB, sul2 and tet(A) or blaPSE-1, floR, aadA2, sul1 and tet(G).
  
  
  CONCLUSIONS
  The prevalence of Salmonella 4,[5],12:i:- has significantly increased from 2003 to 2010 and it is now the fifth most common serotype reported in Canada causing human disease. Similar antimicrobial resistance patterns, phage types and STs have been observed in Europe.
authors.affiliation: Public Health Agency of Canada, Winnipeg, Canada. michael.mulvey@phac-aspc.gc.ca
authors.forename: Michael R
authors.initials: MR
authors.lastname: Mulvey
authors.forename: Rita
authors.initials: R
authors.lastname: Finley
authors.forename: Vanessa
authors.initials: V
authors.lastname: Allen
authors.forename: Lei
authors.initials: L
authors.lastname: Ang
authors.forename: Sadjia
authors.initials: S
authors.lastname: Bekal
authors.forename: Sameh
authors.initials: S
authors.lastname: El Bailey
authors.forename: David
authors.initials: D
authors.lastname: Haldane
authors.forename: Linda
authors.initials: L
authors.lastname: Hoang
authors.forename: Greg
authors.initials: G
authors.lastname: Horsman
authors.forename: Marie
authors.initials: M
authors.lastname: Louie
authors.forename: Lourens
authors.initials: L
authors.lastname: Robberts
authors.forename: John
authors.initials: J
authors.lastname: Wylie
authors.forename: Melissa
authors.initials: M
authors.lastname: McCracken
authors.forename: Stacie
authors.initials: S
authors.lastname: Langner
authors.forename: Rafiq
authors.initials: R
authors.lastname: Ahmed
authors.forename: Helen
authors.initials: H
authors.lastname: Tabor
authors.forename: Matthew
authors.initials: M
authors.lastname: Gilmour
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001434:Bacteriophage Typing; D002170:Canada / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D062665:Epidemiological Monitoring; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology*; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification*; D012703:Serotyping
chemical_list: D000900:Anti-Bacterial Agents
keywords: MDR; Salmonella enterica; resistance