Background: Salmonella enterica subsp. enterica serovar I 4,[5],12:i:- is a variant of Salmonella Typhimurium. S. I 4,[5],12:i:- is a monophasic serovar that lacks the second flagellar antigen (i.e., antigen 1,2 in serovar Typhimurium). This serovar emerged as a common serovar after 1990’s. Multiple reports and outbreaks linked to S. 4,5,12:i:- have occurred globally. Multidrug resistant (MDR) and pan-susceptible strains have been reported. MDR strains with the resistant patterns ACKGSuTm and ACSuGSTTm were reported in Thailand and Spain, respectively (abbrev: ampicillin (A), chloramphenicol (C), kanamycin (K), gentamicin (G) sulfamethoxazole (Su), trimethoprim (Tm), tetracycline (T), streptomycin (S)). Two clones with different gene deletions were identified, one in the US and one in Europe.   

Animal reservoir: Chicken and swine are the major animal reservoirs of this serovar. It has also been found in dogs.

Geographical distribution: Global distribution, this serovar have been reported among the most common serovars in US, EU, and Thailand.

Outbreaks: Several outbreaks have been associated with serovar  I 4,[5],12:i:-.

Year

Location

Associated source

Number of cases

2023Canada-multistateRaw pet food, cattle exposure40
2018US-multistateKosher Chicken Products25

2010

US-multistate

Alfalfa Sprouts

140

2011-2012

US-multistate

probably live-animal markets

>14

2010

US-multistate

Frozen rodents

34

2010

France

Dried pork sausage

69

2007

US-multistate

Pot pie

272

Border rejections: Multiple border rejections associated with serovar I 4,[5],12:i:- have been reported. Here are some examples.

Year

Exporting country

Importing country

Associated source

Product category

2025LithuaniaLatviaPork meat preparation1Meat and meat products (other than poultry)
2024PolandCzech RepublicMinced mixed meat (pork and beef)Meat and meat products (other than poultry)
2021SpainItalyLive mussels (Mytilus galloprovincialis)Bivalve molluscs and products thereof

1Monophasic Salmonella spp. (in 1 out of 5 units) Product (presumably) no longer on the market

Recalls: Multiple recalls associated with serovar I 4,[5],12:i:- have been reported. Here are some examples.

YearLocationRecalled foodType
2023DenmarkPork minced meat1Meat and meat products (other than poultry)
2022Europe: multi-countryChocolate2Confectionery
2021FranceTurkey meat and offalsPoultry meat and poultry meat products
2021FranceChicken meat Poultry meat and poultry meat products

1 Recalled product name: Magre 80/20 de cerdo cong

2 This recall was caused by monophasic Salmonella Typhimurium outbreak linked to chocolate products (Kinder branded chocolate produced by Ferrero). Several countries including Belgium, France, Germany, Ireland, Luxembourg, Netherlands, Norway, and the UK launched the recall. 

Relevant links:

  1. https://webgate.ec.europa.eu/rasff-window/screen/notification/748380
  2. https://webgate.ec.europa.eu/rasff-window/screen/notification/704846
  3. https://webgate.ec.europa.eu/rasff-window/screen/notification/507503
  4. https://webgate.ec.europa.eu/rasff-window/screen/notification/638539
  5. https://www.ecdc.europa.eu/en/news-events/epidemiological-update-monophasic-salmonella-typhimurium-outbreak
  6. https://webgate.ec.europa.eu/rasff-window/screen/notification/459559
  7. https://webgate.ec.europa.eu/rasff-window/screen/notification/505184
  8. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2772592/
  9. http://www.ncbi.nlm.nih.gov/pubmed/19292687
  10. http://wwwnc.cdc.gov/eid/article/20/1/pdfs/13-1179.pdf
  11. https://www.cdc.gov/salmonella/chicken-08-18/index.html
  12. https://finance.yahoo.com/news/public-health-notice-outbreak-extensively-201500243.html
  13. https://doi.org/10.1111/zph.13174