Article Text

PDF
Comparison of five real-time pcr assays for detecting virulence genes in isolates of Escherichia coli from septicaemic neonatal foals
  1. S. Mapes, MS1,
  2. D. M. Rhodes1,
  3. W. D. Wilson, BVMS, MS1,
  4. C. M. Leutenegger, DrVetMed, PhD1 and
  5. N. Pusterla, DrVetMed1
  1. 1 Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, 1 Shields Avenue, Davis, CA 95616, USA
  1. Ms Mapes and Dr Leutenegger are also at the Lucy Whittier Molecular and Diagnostic Core Facility, School of Veterinary Medicine, University of California, 1 Shields Avenue, Davis, CA 95616, USA
  2. Correspondence to Dr Pusterla

Abstract

Fifty-five isolates of Escherichia coli from septicaemic neonatal foals were used to validate five real-time pcr assays targeting different known virulence factor genes: curli fibre (csgD), ferric hydroxamate uptake (fhuA), type 1A pilin (fimA), aerobactin (lutA) and yersiniabactin (fyuA). A pcr assay targeting a universal sequence of the bacterial 16S rrna gene served as quality control. The pcr assays showed good analytical specificity and sensitivity on the basis of sequencing the pcr products, their lack of cross-reactivity with non-E coli organisms, high amplification efficiency and a limit of detection as low as 25 E coli colony-forming units. There were differences between the detection rates and amplification efficiencies for the five virulence genes. The pcr assays targeting genes csgD, fhuA and fyuA were able to detect all 55 E coli isolates, with gene csgD having the best amplification efficiency. The lowest detection rate and amplification efficiency of the E coli isolates was found for the lutA gene.

    Statistics from Altmetric.com

      Request permissions

      If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.