title: Real-time PCRs and fingerprinting assays for the detection and characterization of Salmonella Genomic Island-1 encoding multidrug resistance: application to 445 European isolates of Salmonella, Escherichia coli, Shigella, and Proteus.
abstract: Salmonella Genomic Island-1 (SGI-1) harbors a cluster of genes encoding multidrug resistance (MDR). SGI-1 is horizontally transmissible and is therefore of significant public health concern. This study presents two novel realtime PCRs detecting three SGI-1 protein-coding genes and a SGI-1 fingerprinting assay. These assays were applied to 445 European enterobacterial isolates. Results from real-time PCRs were comparable to those obtained from gelbased PCRs used for the detection of SGI-1, but were rapid to perform and suitable for large-scale screening. Furthermore, real-time PCRs also detected SGI-1 even when only part of the island was present in bacterial isolates. No trace of SGI-1 was detected in isolates other than Salmonella enterica. The fingerprints showed that regions of SGI-1 outside the MDR region exhibited genomic variations between isolates. In conclusion, the realtime PCRs described here are suitable for the detection of SGI-1 in bacterial isolates. Further studies are necessary to elucidate divergence in its non-MDR region.
authors.affiliation: Health Protection Agency, Centre for Infections, London, United Kingdom. corine.amar@hpa.org.uk
authors.forename: Corinne F L
authors.initials: CF
authors.lastname: Amar
authors.forename: Catherine
authors.initials: C
authors.lastname: Arnold
authors.forename: Alan
authors.initials: A
authors.lastname: Bankier
authors.forename: Paul H
authors.initials: PH
authors.lastname: Dear
authors.forename: Beatriz
authors.initials: B
authors.lastname: Guerra
authors.forename: Katie L
authors.initials: KL
authors.lastname: Hopkins
authors.forename: Ernesto
authors.initials: E
authors.lastname: Liebana
authors.forename: Dik J
authors.initials: DJ
authors.lastname: Mevius
authors.forename: E John
authors.initials: EJ
authors.lastname: Threlfall
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016172:DNA Fingerprinting / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis; D018432:Drug Resistance, Multiple / Q000235:genetics*; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D005060:Europe; D044404:Genomic Islands / Q000235:genetics*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D011511:Proteus; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial