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Comparison of five real‐time pcr assays for detecting virulence genes in isolates of Escherichia coli from septicaemic neonatal foals
Author(s) -
Mapes S.,
Rhodes D. M.,
Wilson W. D.,
Leutenegger C. M.,
Pusterla N.
Publication year - 2007
Publication title -
veterinary record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.261
H-Index - 99
eISSN - 2042-7670
pISSN - 0042-4900
DOI - 10.1136/vr.161.21.716
Subject(s) - virulence , escherichia coli , biology , microbiology and biotechnology , aerobactin , gene , polymerase chain reaction , real time polymerase chain reaction , pilin , virulence factor , pilus , enterobacteriaceae , genetics
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 r rna 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.