Korean J Infect Dis.  1997 May;29(3):201-208.

Pulsed-Field Gel Electrophoresis Pattern, Phage Type and Drug Susceptibility of Salmonella typhi Isolates from an Outbreak in Pusan City in 1996

• Shin YH
• Yoo JS
• Park MS
• Kang YH
• Lee BK
• Kim HH

Abstract

BACKGROUND: During the period from April to June 1996, an outbreak of typhoid fever occurred in SuYoung-Ku, Pusan city. We performed the molecular epidemiological analysis and drug susceptibility test for 48 isolates of Salmonella typhi from the outbreak.
METHODS
Chromosomal DNA of S. typhi was digested with the restriction endonuclease Spe I and the resulting restriction polymorphism was observed on pulsed field gel electrophoresis (PFGE). Phage typing was performed using Vi-phages, and antimicrobial susceptibility test was done by Disc diffusion method.
RESULTS
On phage typing, 2 isolates were M1 phage type, 2 E1 phage type and 44 untypable. The PFGE analysis on 14 to 16 chromosomal DNA restriction fragments ranged from 50 Kb to 1000kb showed 2 different patterns of restriction fragments, divided into group A and B. Forty-seven isolates belonged to group A that were allocated into A1 (42 strains), A2 (1 strain), A3 (3 strains), A4 (1 strain), and one strain was grouped into group B. In the F-value of genetic similarity of the epidemic S. typhi strains, there was low similarity (F value:0.2-0.258) between group A strains and group B strains. However, the subgroup strains (A1-A4) showed high similarity (F value:0.8-0.897) each other. The drug susceptibility test showed susceptibility to ampicillin, carbenicillin, cephalothin, chloramphenicol, tobramycin, gentamicin, kanamycin, nalidixic acid, neomycin, polymyxin B, streptomycin, tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin and norfloxacin.
CONCLUSION
This study showed that phage typing and PFGE were very useful as a tool to investigate molecular analyses of epidemic S. typhi strains this study.

Keyword

Salmonella typhi; Phage typing; Pulsed-field gel electrophoresis; Antimicrobial susceptibility

MeSH Terms

Ampicillin
Bacteriophage Typing
Bacteriophages*
Busan*
Carbenicillin
Cephalothin
Chloramphenicol
Ciprofloxacin
Diffusion
DNA
DNA Restriction Enzymes
Electrophoresis, Gel, Pulsed-Field*
Epidemics
Gentamicins
Kanamycin
Nalidixic Acid
Neomycin
Norfloxacin
Polymyxin B
Salmonella typhi*
Salmonella*
Streptomycin
Tetracycline
Tobramycin
Trimethoprim, Sulfamethoxazole Drug Combination
Typhoid Fever
Ampicillin
Carbenicillin
Cephalothin
Chloramphenicol
Ciprofloxacin
DNA
DNA Restriction Enzymes
Gentamicins
Kanamycin
Nalidixic Acid
Neomycin
Norfloxacin
Polymyxin B
Streptomycin
Tetracycline
Tobramycin