Clustering analysis of Salmonella enterica serovar Typhi isolates in Korea by PFGE, ribotying, and phage typing.
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.
Kim
Shukho
S
Center for Infectious Diseases, Korea National Institute of Health, Seoul, South Korea.
Kim
Sung-Hun
SH
Park
Jeong-Hyun
JH
Lee
Kyung-Shin
KS
Park
Mi-Sun
MS
Lee
Bok Kwon
BK
D001434:Bacteriophage Typing; D001769:Blood / Q000382:microbiology; D002353:Carrier State / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D005243:Feces / Q000382:microbiology; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D021521:Ribotyping; D012485:Salmonella typhi / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification; D014195:Travel; D014435:Typhoid Fever / Q000453:epidemiology / Q000382:microbiology*