Page History

Background: Salmonella enterica subsp. enterica serovar serovar Choleraesuis has the antigenic formula 6,7:c:1,5 . There are four other Salmonella serovars with the same antigenic formula. S. Paratyphi Cof the O:7 (C₁) serogroup. Within S. Choleraesuis there are two biovars, S. Choleraesuis var. Kunzendorf ,and S. Choleraesuis var. Decatur, and S. Typhisuis all share a common antigenic formula. Differentiation is accomplished through biochemical analysis, see Table 1 below.  S. Decatur. S. Choleraesuis is utilized as an H₂S negative QC strain in the USDA -MLG.  Microbiology Laboratory Guidebook, Chapter 4: Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, Siluriformes (Fish) Products, Carcass and Environmental Sponges. S. Choleraesuis was one of the first types of Salmonella discovered. Theobold Theobald Smith and Daniel Salmon discovered SalmonellaS. Choleraesuis in 1885 while studying swine diseases. This serovar is highly host adapted to swine swine and causes swine paratyphoid.  Pigs that have been infected can shed the organism for up to 12 weeks resulting environmental contamination and infection of other animals in spread of the disease among the herd. Human  Human cases from this serovar in the United States are rare, but nearly half of infections are invasive and can be severe. While it is not one of the leading serovars associated with nontyphoidal salmonellosis (NTS), S. Choeraesuis is one of the top servors implicated in NTS fatalities. In  In the 1990s, S. Cholerasuis Choleraesuis was one of the top 10 serovars isolated from human cases in Taiwan. Improvements in swine husbandry, including vaccination of pigs, has significantly substantially reduced the occurrence of disease Choleraesuis in Taiwan. Outbreaks from consuming contaminated pork are rare. 

The in-silico serotyping tool SeqSero2, which is used by NCBI PD, cannot differentiate between Salmonella Paratyphi C, Choleraesuis, or Typhisuis because there are also two other serovoars with the same antigenic formula as S. Choleraesuis: S. Paratyphi C.  and S. Typhisuis. Additional markers are required to accurately determine the serotype of Choleraesuis. Differentiation is accomplished through biochemical analysis, see Table 1 below. NCBI PD link for serovar Paratyphi C or Choleraesuis or Typhisuis: https://www.ncbi.nlm.nih.gov/pathogens/isolates/#(taxgroup_name:%22Salmonella%20enterica%22)%20AND%20computed_types:(%22serotype=Paratyphi%20C%20or%20Choleraesuis%20or%20Typhisuis%22)

Table 1: Differention of serovars with antigenic formula 6,7:c:1,5

Genetic characteristics: Serovar Choleraesuis has been found to be polyphyletic with four lineages identified. The majority of Salmonella Choleraesuis strains linked to human infections, particularly in Asian countries, exhibit MDR. This resistance is often attributed to traditional mobile genetic elements, such as transposons and plasmids, as well as integrative elements. These elements facilitate the dissemination of antimicrobial resistance genes within the bacterial genome via gene cassettes through site-specific recombination. Salmonella Choleraesuis in pigs harbors a 50-kb virulence plasmid including the spv operon. The spv operon is essential for the systemic phase of infection in certain hosts, with the virulence plasmid size being serotype-specific. The strains were cleared of a 50-kb virulence plasmid and exhibited significantly higher 50% lethal doses (LD50) in mice.

Animal reservoir: Swine Animal reservoir: Swine is the reservoir of this serovar.

Geographical distribution: Serovar Choleraesius Serovar Choleraesuis has been reported in North America, Asia, and Europe. Most cases are in pigs. Relevant links and references: worldwide. Although Salmonella Derby is rarely detected in human cases in the United States and European regions, it is the main cause of salmonellosis in several Asian countries such as Thailand and Taiwan.

Animal outbreaks: Multiple swine outbreaks linked to serovar Choleraesuis have been reported. Below are examples. 

Border rejections: There have been no recent border rejections linked to this serovar. 

Recalls:

Relevant links:

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC387403/
2. https://www.wiley.com/en-us/Diseases+of+Swine%2C+11th+Edition-p-9781119350859
3. https://www.fsis.cdcusda.gov/sites/salmonella/reportspubs/salmonella-atlas/serotype-snapshots.htmldefault/files/media_file/2021-08/MLG-4.11.pdf
4. https://pmchttp://www.ncbi.nlm.nih.gov/pubmedarticles/PMC2634653/17217090
5.  https://wwwpmc.ncbi.nlm.nih.gov/pmc/articles/PMC387403PMC10610219/
6.  https://www.pasteurcdc.frgov/sitessalmonella/defaultreportspubs/files/veng_0.pdf salmonella-atlas/serotype-snapshots.html
7. https://wwwnc.cdc.gov/eid/article/20/4/13-0240_article
8. https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2025.1547190/full
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC7692705/#:~:text=Choleraesuis%20strains%20that%20have%20caused,resistance%20genes%20within%20the%20bacterial
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC6206682/#CR1
11. https://scholar.google.com/scholar_lookup?title=Salmonella%20in%20domestic%20animals&author=MP%20Stevens&author=JT%20Gray&publication_year=2013&
12. https://www.sva.se/media/nyglg2zq/sva-rapport-64-surveillance-2019.pdf
13.  https://www.hindawisciencedirect.com/journals/tswj/2015/520179/ /science/article/pii/S0378113521003059#tbl0005
14. https://pubmed.ncbi.nlm.nih.gov/25703158/
15. https://researchprofiles.ku.dk/en/publications/udbrud-af-salmonellose-for%C3%A5rsaget-af-salmonella-enterica-susp-ent-2
16. https://webgate.ec.europa.eu/rasff-window/screen/notification/510881