Clustering analysis of Salmonella enterica serovar Typhi isolates in Korea by PFGE, ribotying, and phage typing

Foodborne Pathog Dis. 2009 Jul-Aug;6(6):733-8. doi: 10.1089/fpd.2008.0212.

Abstract

Salmonella enterica serovar Typhi is a Gram-negative bacterium causing the acute febrile disease typhoid fever. In Korea from 2004 to 2006, a total of 51 Salmonella Typhi isolates were identified in stool and blood from healthy carriers and patients with or without overseas travel histories. In this study, antibiogram, pulsed-field gel electrophoresis (PFGE), and automated ribotyping were performed as molecular epidemiological methods with phage typing as a classical subtyping tool of the isolates. Only two isolates were multidrug resistant and 82.3% of the isolates were susceptible to 16 antimicrobial agents tested. When the dendrogram was created based on the PFGE results, the subtypes could be clustered into five groups by 80% similarity criterion. The PFGE patterns of 31 isolates (60.8%) belonged to Cluster 3, the predominant cluster in the study. Three overseas travel-associated cases were differentiated into Cluster 4 of which three isolates were nalidixic acid or multidrug resistant. Major phage type and ribotype were A and PvuII-436-8-S-6, respectively. This study also showed the prevalence of PFGE Cluster 3 in Korea by clustering analysis and the link between some typhoid cases and travel to Cambodia, India, or Indonesia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriophage Typing*
  • Blood / microbiology
  • Carrier State / microbiology
  • Drug Resistance, Multiple, Bacterial
  • Electrophoresis, Gel, Pulsed-Field*
  • Endemic Diseases
  • Feces / microbiology
  • Humans
  • Korea / epidemiology
  • Microbial Sensitivity Tests
  • Ribotyping*
  • Salmonella typhi / classification*
  • Salmonella typhi / drug effects
  • Salmonella typhi / isolation & purification
  • Travel
  • Typhoid Fever / epidemiology
  • Typhoid Fever / microbiology*