title: Multiple-Locus Variable Number Tandem Repeat Analysis of Klebsiella pneumoniae: Comparison with Pulsed-Field Gel Electrophoresis.
abstract: OBJECTIVE
  To assess whether multiple-locus variable-number tandem repeat analysis (MLVA) could replace pulsed-field gel electrophoresis (PFGE) for genotyping of Klebsiella pneumoniae, this study was conducted to compare the typeability, discriminatory power, and concordance of these methods.
  
  
  METHODS
  We used the nine variable number tandem repeat (VNTR) loci scheme to test its suitability for differentiating 114 ESBL-producing K. pneumoniae isolates collected from different clinical specimens in three hospitals of Tehran, Iran between April and December 2011. PFGE with XbaI was performed and the results were compared with those obtained by typing with MLVA.
  
  
  RESULTS
  MLVA and PFGE yielded 44 and 64 types, respectively. Simpson's Diversity Index of MLVA was 0.896 (a 95% confidence interval of 0.850-0.942) and of PFGE was 0.962 (a 95% confidence interval of 0.943-0.981). Congruence between PFGE and MLVA was low. The adjusted Wallace coefficient of PFGE to MLVA was 0.946; however, MLVA was less able to predict PFGE type (32.5%). A range of 2-12 alleles was identified at VNTR loci with Simpson's diversity values between 0.017 and 0.818.
  
  
  CONCLUSIONS
  MLVA is a PCR-based typing method and is much easier and more rapid in comparison to PFGE. These data indicate that the MLVA typing scheme used in this study is discriminative and reliable for typing of K. pneumoniae. However, optimization of the VNTR markers is required to improve the discriminatory power of the method.
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University , Tehran, Iran .
authors.forename: Safoura
authors.initials: S
authors.lastname: Derakhshan
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University , Tehran, Iran .
authors.forename: Shahin
authors.initials: S
authors.lastname: Najar-Peerayeh
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University , Tehran, Iran .
authors.forename: Bita
authors.initials: B
authors.lastname: Bakhshi
mesh_terms: D000483:Alleles; D015373:Bacterial Typing Techniques / Q000295:instrumentation / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000295:instrumentation / Q000379:methods*; D056426:Genetic Loci; D005838:Genotype; D006761:Hospitals; D006801:Humans; D007492:Iran; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D018598:Minisatellite Repeats; D005810:Multigene Family; D058885:Multilocus Sequence Typing / Q000295:instrumentation / Q000379:methods*; D010802:Phylogeny
chemical_list: D004269:DNA, Bacterial
keywords: ESBL; Klebsiella pneumoniae; MLVA; PFGE