title: Comparison of pulsed-field gel electrophoresis & repetitive sequence-based PCR methods for molecular epidemiological studies of Escherichia coli clinical isolates.
abstract: OBJECTIVE
  PFGE, rep-PCR, and MLST are widely used to identify related bacterial isolates and determine epidemiologic associations during outbreaks. This study was performed to compare the ability of repetitive sequence-based PCR (rep-PCR) and pulsed-field gel electrophoresis (PFGE) to determine the genetic relationships among Escherichia coli isolates assigned to various sequence types (STs) by two multilocus sequence typing (MLST) schemes.
  
  
  METHODS
  A total of 41 extended-spectrum β-lactamase- (ESBL-) and/or AmpC β-lactamase-producing E. coli clinical isolates were included in this study. MLST experiments were performed following the Achtman's MLST scheme and the Whittam's MLST scheme, respectively. Rep-PCR experiments were performed using the DiversiLab system. PFGE experiments were also performed.
  
  
  RESULTS
  A comparison of the two MLST methods demonstrated that these two schemes yielded compatible results. PFGE correctly segregated E. coli isolates belonging to different STs as different types, but did not group E. coli isolates belonging to the same ST in the same group. Rep-PCR accurately grouped E. coli isolates belonging to the same ST together, but this method demonstrated limited ability to discriminate between E. coli isolates belonging to different STs.
  
  
  CONCLUSIONS
  These results suggest that PFGE would be more effective when investigating outbreaks in a limited space, such as a specialty hospital or an intensive care unit, whereas rep-PCR should be used for nationwide or worldwide epidemiology studies.
authors.forename: Il Kwon
authors.initials: IK
authors.lastname: Bae
authors.forename: Juwon
authors.initials: J
authors.lastname: Kim
authors.forename: Je Young Hannah
authors.initials: JY
authors.lastname: Sun
authors.affiliation: Department of Laboratory Medicine & Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Department of Chemistry, Yonsei University, Seoul, Korea.
authors.forename: Yong-Rok
authors.initials: YR
authors.lastname: Kim
authors.forename: Kang-Kyun
authors.initials: KK
authors.lastname: Wang
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology* / Q000472:pathogenicity; D006801:Humans; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction / Q000379:methods; D001618:beta-Lactamases / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases