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Background: Salmonella enterica subsp. enterica serovar Hartford (antigenic formula 6,7:y:e,n,x) is a serovar of the O:7 (C1) serogroup. It has been isolated from a dairy-producing environment. Serovar Hartford was previously recovered from non-outbreak cattle herds. Serovar Hartford was found as highly persistent in all low-aw food ingredients.
NCBI PD link for serovar Hartford: https://www.ncbi.nlm.nih.gov/pathogens/isolates/#(taxgroup_name:%22Salmonella%20enterica%22)%20AND%20computed_types:(%22serotype=Hartford%22)
Genetic characteristics: Serovar Hartford has been found to be polyphyletic with two lineages identified and one stand-alone singleton that does not cluster with any other Salmonella Hartford isolates. In a US study, serovar Hartford isolates were found to be pansusceptible to all antimicrobials tested using the Kirby-Bauer method. Additionally, all sixHartford isolates recovered from mesenteric lymph nodes on one of farms were indistinguishable based on pulsed-field gel electrophoresis analysis.
Animal reservoir: Salmonella Hartford was found in chicken, calves, horses, dogs, and wild animals such as wild black bears.
Geographical distribution: Serovar Hartford has been found in the US, Canada, Australia, the UK, Hungary, and China, and the U.S.
Outbreaks: Outbreaks have been associated with S. Hartford.Human outbreaks:
| Year | Location | Associated Source | Number of Cases | ||||
|---|---|---|---|---|---|---|---|
| 19952023 | US: FL | Unpasteurized orange juice | 62* | 2010 | US: Multi-statemultistate | Not identified identified | 7554 |
| 2014 | US: Multi-statemultistate | Organic sprouted chia powder1 | 731 | ||||
| 20232010 | US | Not yet identified | at least 47 | : multistate | Not identified | 75 | |
| 1995 | US: FL | Unpasteurized orange juice2 | 62 |
1 Salmonella Newport (20 cases), Salmonella Hartford (7 cases), or Salmonella Oranienburg (4 cases)
2 *Salmonella Gaminara was also involved in this outbreak.
Border rejections: There have been no recent border rejections linked to this serovar.
Recalls: There have been no recent recalls linked to this serovar.
Relevant linksRelevant links and references:
- https://www.cdcliebertpub.govcom/salmonelladoi/2010/restaurant-chain-a-8-4-10.htmlhttps://jamanetwork.com/journals/jama/fullarticle/18812810.1089/fpd.2017.2303?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
- https://www.foodsafetynewssciencedirect.com/tag/salmonella-hartford/science/article/pii/S0362028X22106150
- https://www.jstorfrontiersin.org/stablejournals/microbiology/pdfarticles/24320783.pdf?refreqid=excelsior%3Ada8966aa9c6b88949ad11ca86de2b59c&ab_segments=&origin=&initiator=&acceptTC=1https://agris.fao.org/agris-search/search.do?recordID=CN921122910.3389/fmicb.2025.1547190/full
- https://www.liebertpub.com/doi/10.1089/fpd.2017.2303pmc.ncbi.nlm.nih.gov/articles/PMC4652083/
- https://www.mdpi.com/2076-2607/11/2/403
- https://www.jstor.org/stable/24320783
- https://www.fda.gov/food/outbreaks-foodborne-illness/investigations-foodborne-illness-outbreaks
- https://archive.cdc.gov/www_cdc_gov/salmonella/newport-05-14/index.html
- https://archive.cdc.gov/#/details?url=https://www.cdc.gov/salmonella/2010/restaurant-chain-a-8-4-10.html
- https://jamanetwork.com/journals/jama/fullarticle/188128