In August 2017, an increased incidence of Salmonella Bareilly was detected in the Czech Republic. An investigation was conducted with Slovakia to confirm the outbreak and identify the source. Probable outbreak cases were defined as cases with laboratory-confirmed S. Bareilly reported in either of the national surveillance systems, and/or the Czech and Slovak National Reference Laboratory databases from July 2017. Confirmed cases had the pulsed-field gel electrophoresis (PFGE) outbreak pulsotype or up to 5 alleles difference from outbreak cluster members by core genome multilocus sequence typing (cgMLST). PFGE and whole genome sequencing were used for isolate comparison. The same trawling questionnaire was used in both countries. By the end of October 2018, 325 cases were identified. Among 88 human S. Bareilly isolates analysed by PFGE, 82 (93%) shared an identical pulsotype; cgMLST of 17 S. Bareilly human isolates showed 1-2 allele difference. The trawling questionnaire excluded consumption of unusual or imported foods. In September 2018, an isolate closely related to the outbreak isolates was identified in a powdered egg product. A spray dryer was recognised as the contamination source and the production plant was closed. Using molecular typing methods, we detected a diffuse cross-border outbreak caused by S. Bareilly.

Department of Molecular Endocrinology Institute of Endocrinology Prague Czech Republic

ECDC Fellowship Programme public health microbiology path Stockholm Sweden

Food Safety Division State Veterinary Administration Prague Czech Republic

National Institute of Public Health Prague Czech Republic

National Reference Centre for Salmonellosis Public Health Authority of the Slovak Republic Bratislava Slovakia

National Reference Laboratory for salmonella State Veterinary Institute Prague Prague Czech Republic

Public Health Authority of the Slovak Republic Regional Public Health Authority Trenčín Slovakia

Veterinary Research Institute Brno Czech Republic

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Pires SM, Fischer-Walker CL, Lanata CF, Devleesschauwer B, Hall AJ, Kirk MD, et al. Aetiology-specific estimates of the global and regional incidence and mortality of diarrhoeal diseases commonly transmitted through food. PLoS One. 2015;10(12):e0142927. 10.1371/journal.pone.0142927 PubMed DOI PMC

European Food Safety Authority and European Centre for Disease Prevention and Control (EFSA and ECDC) . The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2017. EFSA J. 2018;16(12):e05500. PubMed PMC

Grimont PAD, Weill F-X. Antigenic formulae of the Salmonella servovars: WHO collaborating centre for reference and research on Salmonella. 9th Edition, Institute Pasteur. 2007.

Hendriksen RS, Vieira AR, Karlsmose S, Lo Fo Wong DMA, Jensen AB, Wegener HC, et al. Global monitoring of Salmonella serovar distribution from the World Health Organization Global Foodborne Infections Network Country Data Bank: results of quality assured laboratories from 2001 to 2007. Foodborne Pathog Dis. 2011;8(8):887-900. 10.1089/fpd.2010.0787 PubMed DOI

Bridges RF, Scott WM. A new organism causing paratyphoid fever in India. J R Army Med Corps. 1931;56:241-9.

Cleary P, Browning L, Coia J, Cowden J, Fox A, Kearney J, et al. A foodborne outbreak of Salmonella Bareilly in the United Kingdom, 2010. Euro Surveill. 2010;15(48):8. 10.2807/ese.15.48.19732-en PubMed DOI

Hoffmann M, Luo Y, Monday SR, Gonzalez-Escalona N, Ottesen AR, Muruvanda T, et al. Tracing origins of the Salmonella Bareilly strain causing a food-borne outbreak in the United States. J Infect Dis. 2016;213(4):502-8. 10.1093/infdis/jiv297 PubMed DOI

Dědičová D, Pihávková H, Mašková J. Humánní kmeny salmonel identifikované v NRL pro salmonely v průběhu roku 2008. [Human strains of Salmonella identified in the NRL for Salmonella in 2008]. Zprávy CEM (SZÚ, Praha) 2009; 18(5):164-7. Czech. Available from: http://www.szu.cz/uploads/documents/CeM/Zpravy_EM/18_2009/5_kveten/164salm.pdf

Státní veterinární správa (State Veterinary Administration). Národní programy tlumení salmonel – Metodika kontroly zdraví a nařízené vakcinace na rok 2019. [National programmes for Salmonella control - methods for health control and ordered vaccination in 2019]. Prague: The State Authority; 2019. [Accessed: 22 Feb 2019]. Czech. Available from: https://www.svscr.cz/zdravi-zvirat/programy-tlumeni-vyskytu-salmonel/

European Commission. Commission implementing decision (EC) No 517/2011 of 25 May 2011 implementing Regulation (EC) No 2160/2003 of the European Parliament and of the Council as regards a Union target for the reduction of the prevalence of certain Salmonella serotypes in laying hens of Gallus gallus and amending Regulation (EC) No 2160/2003 and Commission Regulation (EU) No 200/2010. Official Journal of the European Union. Luxembourg: Publications Office of the European Union. 26 May 2011. Available from: https://eur-lex.europa.eu/eli/reg/2011/517/oj

European Commission. Commission implementing decision (EU) No 506/2012EU of 8 August 2012 amending Decision 2002/253/EC laying down case definitions for reporting communicable diseases to the Community network under Decision No 2119/98/EC of the European Parliament and of the Council (notified under document C (2012) 5538). Official Journal of the European Union. Luxembourg: Publications Office of the European Union. 27 Sep 2012. Available from: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:262:0001:0057:EN:PDF

Chiou CS, Lin JM, Chiu CH, Chu CH, Chen SW, Chang YF, et al. Clonal dissemination of the multi-drug resistant Salmonella enterica serovar Braenderup, but not the serovar Bareilly, of prevalent serogroup C1 Salmonella from Taiwan. BMC Microbiol. 2009;9(1):264. 10.1186/1471-2180-9-264 PubMed DOI PMC

Nadon C, Van Walle I, Gerner-Smidt P, Campos J, Chinen I, Concepcion-Acevedo J, et al. PulseNet International: Vision for the implementation of whole genome sequencing (WGS) for global food-borne disease surveillance. Euro Surveill. 2017;22(23):30544. 10.2807/1560-7917.ES.2017.22.23.30544 PubMed DOI PMC

Besser JM, Carleton HA, Trees E, Stroika SG, Hise K, Wise M, et al. Interpretation of whole-genome sequencing for enteric disease surveillance and outbreak investigation. Foodborne Pathog Dis. 2019;16(7):504-12. 10.1089/fpd.2019.2650 PubMed DOI PMC

Centre for Disease Control and Prevention (CDC). Standard operating procedure for PulseNet PFGE of Escherichia coli O157:H7, Escherichia coli non-O157 (STEC), Salmonella serotypes, Shigella sonnei and Shigella flexneri; Atlanta: CDC; 2013. PNL05 Last Updated December 2017. Available from: http://www.cdc.gov/pulsenet/pdf/ecoli-shigella-salmonella-pfge-protocol-508c.pdf

Zhou Z, Alikhan NF, Sergeant MJ, Luhmann N, Vaz C, Francisco AP, et al. Grapetree: Visualization of core genomic relationships among 100,000 bacterial pathogens. Genome Res. 2018; bioRxiv. 10.1101/gr.232397.117 PubMed DOI PMC

Stamatakis A. RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics. 2014;30(9):1312-3. 10.1093/bioinformatics/btu033 PubMed DOI PMC

Rambaut A. FigTree version 1.3.1. 2009. Available from: http://tree.bio.ed.ac.uk.

Meinen A, Simon S, Banerji S, Szabo I, Malorny B, Borowiak M, et al. Salmonellosis outbreak with novel Salmonella enterica subspecies enterica serotype (11:z41:e,n,z15) attributable to sesame products in five European countries, 2016 to 2017. Euro Surveill. 2019;24(36):1800543. 10.2807/1560-7917.ES.2019.24.36.1800543 PubMed DOI PMC

Pijnacker R, Dallman TJ, Tijsma ASL, Hawkins G, Larkin L, Kotila SM, et al. An international outbreak of Salmonella enterica serotype Enteritidis linked to eggs from Poland: a microbiological and epidemiological study. Lancet Infect Dis. 2019;19(7):778-86. 10.1016/S1473-3099(19)30047-7 PubMed DOI

Dallman T, Inns T, Jombart T, Ashton P, Loman N, Chatt C, et al. Phylogenetic structure of European Salmonella Enteritidis outbreak correlates with national and international egg distribution network. Microb Genom. 2016;2(8):e000070. 10.1099/mgen.0.000070 PubMed DOI PMC

Cahill SM, Wachsmuth IK, Costarrica ML, Ben Embarek PK. Powdered infant formula as a source of Salmonella infection in infants. Clin Infect Dis. 2008;46(2):268-73. 10.1086/524737 PubMed DOI