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S. Hvittingfoss

At a Glance
Antigenic Formula 16:b:e,n,x
Serogroup O:16 (I)
NCBI Pathogen Detection View isolates

Background Information

Salmonella enterica subsp. enterica serovar Hvittingfoss (antigenic formula 16:​b:e,n,x) is a serovar of the O:16 (I) serogroup. Found in wildand domesticated reptiles and amphibians, and in food-producing mammals, this is a rare serovar, though it has been linked to human foodborne outbreaks. Infection with serovar Hvittingfosscan lead to symptoms such as diarrhea, fever, nausea, abdominal pain, dizziness, and other related conditions. The first-ever reported case of acute gastroenteritis caused by serovar Hvittingfoss in India was described in a case report.

Genetic Characteristics

Serovar Hvittingfoss has been found to be polyphyletic with four lineages identified and one stand-alone singleton that does not cluster with any other Salmonella Hvittingfoss isolates. ST446 was identified as the primary lineage among documented Hvittingfoss isolates in China. ST446 was alsothe outbreak strain linked to consumption of sprouted seeds in Norway. Fang et al. revealed the concurrent emergence of an outbreak-associated Hvittingfoss clone in regions of England. In Bar-tailed Godwits (Limosa lapponica) from Roebuck Bay in Northwestern Australia, all Hvittingfoss isolates collected were found to carry the aminoglycoside resistance gene aac(6’)-Iaa, a gene conserved across all Salmonella serovars but typically not expressed.

Animal Reservoir

Serovar Hvittingfoss has been mainly recovered from amphibians (both those raised as pets and for food items) and reptiles.

Geographical Distribution

Serovar Hvittingfoss has been reported worldwide such in Australia, Europe and the US.

Human/Animal Outbreaks

Year Location Associated source Number of cases
2023-2025 Norway Sprouted seeds1 12
2019 Hong Kong (China) Toasted beef2 6
2016 Australia: multistate Rockmelons 97
2010 US: IL Subway restaurant 103

1 Multiple serovars were involved in this prolonged outbreak. Here, the case number is only associated with infection by the serovar Hvittingfoss.

2 Travel-associated

Border Rejections

Year Exporting country Importing country Associated source Product category
2020 India Greece Hulled sesame seeds Nuts, nut products and seeds

Recalls

Year Location Recalled food Type
2024 Norway Sprouts seeds1 Nuts, nut products and seeds
2016 Australia Rockmelons2 Fruits and vegetables

1 This recall was related to the prolonged cross-border multi-serovar Salmonella outbreak linked to consumption of sprouted seed described above.

2 The Northern Territory based company “Red Dirt” issued a trade level recall. This recall was caused by the outbreak described above.

References

  1. https://pubmed.ncbi.nlm.nih.gov/3833829/
  2. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0087933
  3. https://www.journalofinfection.com/article/S0163-4453(22)00071-8/fulltext
  4. https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2025.1547190/full
  5. https://journals.asm.org/doi/10.1128/aem.01312-20
  6. https://pmc.ncbi.nlm.nih.gov/articles/PMC11675239/
  7. https://onlinelibrary.wiley.com/doi/10.1111/zph.12286
  8. https://www.journalofinfection.com/article/S0163-4453(22)00071-8/fulltext
  9. https://pubmed.ncbi.nlm.nih.gov/32737126/#:~:text=IMPORTANCESalmonella%20is%20a%20zoonotic%20pathogen,shorebirds;%20wildlife;%20zoonotic%20potential.
  10. https://marlerclark.com/news_events/illinois-subway-salmonella-hvittingfoss-outbreak
  11. https://webgate.ec.europa.eu/rasff-window/screen/notification/434036
  12. https://www.food-safety.com/articles/10195-salmonella-outbreak-linked-to-sprouts-sickened-509-people-over-two-years-in-ten-european-countries
  13. https://www.wslhd.health.nsw.gov.au/News/2016/Avoid-recalled-rockmelon-after-Salmonella-outbreak--NSW-Health