Comparison of a semi-automated rep-PCR system and multilocus sequence typing for differentiation of Salmonella enterica isolates.
The accurate sub-typing of Salmonella enterica isolates is essential for epidemiological investigations and surveillance of Salmonella infections. Salmonella isolates are currently identified using the Kauffman-White serotyping scheme. Multilocus sequence typing (MLST) schemes have been developed for the major bacterial pathogens including Salmonella and have assisted in understanding the molecular epidemiology and population biology of these organisms. Recently, the DiversiLab rep-PCR system has been developed using micro-fluidic chips to provide standardized, semi-automated fingerprinting for pathogens including S. enterica. In the current study, 71 isolates of S. enterica, representing 21 serovars, were analyzed using MLST and the DiversiLab rep-PCR system. MLST was able to identify 31 sequence types (STs), while the DiversiLab system revealed 38 DiversiLab types (DTs). The rep-PCR distinguished isolates of different serovars and showed greater discriminatory power (0.95) than MLST typing (0.89). Rep-PCR exhibited 92% concordance with MLST and 90% with serotyping, while the concordance level of MLST typing with serotyping was 96%, representing a strong association. Comparison of rep-PCR profiles with those held in an online library database led to the accurate prediction of serovar in 63% of cases and resulted in inaccurate predictions for 10% of profiles. MLST and the rep-PCR system may provide useful additional informative techniques for the molecular identification of S. enterica. We conclude that the DiversiLab rep-PCR system may provide a rapid (less than 4h) and standardized method for sub-typing isolates of S. enterica.
Ben-Darif
Elloulu
E
Department of Medical Microbiology, School of Medicine, University of Manchester, Clinical Sciences Building, Manchester Royal Infirmary, Oxford Road, Manchester, M13 9WL, United Kingdom.
De Pinna
Elizabeth
E
Threlfall
E John
EJ
Bolton
Frederic J
FJ
Upton
Mathew
M
Fox
Andrew J
AJ
D001331:Automation / Q000379:methods; D015373:Bacterial Typing Techniques; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D019779:Salmonella enterica / Q000145:classification* / Q000235:genetics*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000379:methods
D004269:DNA, Bacterial