Characterization of antimicrobial resistance, molecular and phage types of Salmonella enterica serovar Typhi isolations

W. H.B. Demczuk, R. Finley, C. Nadon, A. Spencer, M. Gilmour, L. K. Ng

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


Isolation rates in Canada of Salmonella enterica serovar Typhi increased from 029 to 055 isolations/100 000 population during 2000-2006. Although no ciprofloxacin resistance was detected, nalidixic acid resistance increased from 41% to 80%. Multidrug-resistant S. Typhi represented 18% of the strains tested. Pulsed-field gel electrophoresis (PFGE) analysis of 222 isolates resulted in 91 distinct patterns clustering into four major genetic similarity groups. The five most frequently occurring PFGE patterns accounted for 46% of the isolates. Drug-resistant isolates predominantly occurred in one PFGE similarity group. There were 39 phage types identified in 826 isolates analysed with 60% described by five phage types; 134 were untypable. The phage types associated with multidrug resistance were phage types 53, B1, D1, E1, E9, G3 and M1. Improved integration of epidemiological and laboratory case data will facilitate the protection of public health in Canada during an era of increasing travel and globalization.

Original languageEnglish
Pages (from-to)1414-1426
Number of pages13
JournalEpidemiology and Infection
Issue number10
Publication statusPublished - Oct 2010


  • Antibiotic resistance
  • molecular epidemiology
  • public health microbiology
  • Salmonella (Typhi)
  • Salmonella typing

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