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.
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.
Amar
Corinne F L
CF
Health Protection Agency, Centre for Infections, London, United Kingdom. corine.amar@hpa.org.uk
Arnold
Catherine
C
Bankier
Alan
A
Dear
Paul H
PH
Guerra
Beatriz
B
Hopkins
Katie L
KL
Liebana
Ernesto
E
Mevius
Dik J
DJ
Threlfall
E John
EJ
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
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial