TY - JOUR AU - Gymoese, Pernille AU - Sørensen, Gitte AU - Litrup, Eva AU - Olsen, John Elmerdal AU - Nielsen, Eva Møller AU - Torpdahl, Mia T1 - Investigation of Outbreaks of Salmonella enterica Serovar Typhimurium and Its Monophasic Variants Using Whole-Genome Sequencing, Denmark T2 - Emerging Infectious Disease journal PY - 2017 VL - 23 IS - 10 SP - 1631 SN - 1080-6059 AB - Whole-genome sequencing is rapidly replacing current molecular typing methods for surveillance purposes. Our study evaluates core-genome single-nucleotide polymorphism analysis for outbreak detection and linking of sources of Salmonella enterica serovar Typhimurium and its monophasic variants during a 7-month surveillance period in Denmark. We reanalyzed and defined 8 previously characterized outbreaks from the phylogenetic relatedness of the isolates, epidemiologic data, and food traceback investigations. All outbreaks were identified, and we were able to exclude unrelated and include additional related human cases. We were furthermore able to link possible food and veterinary sources to the outbreaks. Isolates clustered according to sequence types (STs) 19, 34, and 36. Our study shows that core-genome single-nucleotide polymorphism analysis is suitable for surveillance and outbreak investigation for Salmonella Typhimurium (ST19 and ST36), but whole genome–wide analysis may be required for the tight genetic clone of monophasic variants (ST34). KW - Salmonella Typhimurium KW - outbreaks KW - surveillance KW - genomics KW - sequence analysis KW - molecular typing KW - single-nucleotide polymorphism KW - SNP KW - foodborne disease KW - bacteria KW - food safety KW - whole-genome sequencing KW - monophasic variants KW - multilocus variable-number tandem-repeat analysis KW - MLVA KW - Denmark DO - 10.3201/eid2310.161248 UR - https://wwwnc.cdc.gov/eid/article/23/10/16-1248_article ER - End of Reference