Background: Salmonella enterica subsp. enterica serovar Saintpaul (antigenic formula 1,4,[5],12:e,h:1,2) is a serovar of the O:4 (B) serogroup. In 1940, serovar Saintpaul was first isolated from turkey in US.

In the U.S. it ranks among the top 15 serovars causing human salmonellosis.  In Oceania, this serovar is the fourth most common serovar in humans. In addition, S. Saintpaul is commonly reported in Europe and outbreaks have been linked to internationally imported food (e.g., from Mexico).

NCBI PD link for serovar Saintpaul: https://www.ncbi.nlm.nih.gov/pathogens/isolates/#(taxgroup_name:%22Salmonella%20enterica%22)%20AND%20computed_types:(%22serotype=Saintpaul%22)

Genetic characteristics: Chen et al. found that serovar Saintpaul appeared to be polyphyletic with four distinct phylogenetic groups identified. Within serovar Saintpaul, the comparative genomic analysis revealed 384 and 619 genes enriched in isolates from 5 human-associated (HA) and 4 non-human-associated (NHA) SNP clusters, respectively, that showed the strongest association with their isolation sources. This included five known HA-linked virulence genes located on Gifsy-1/Gifsy-2 prophages. Additionally, premature stop codons were more prevalent in 3 HA and 7 NHA genes. Cell culture experiments with representative strains from 4 HA and 3 NHA clusters found no increased invasion or intracellular survival capability in HA SNP clusters. However, the presence of sodCI (encoding a superoxide dismutase)—detected in 4 HA and 1 NHA clusters—correlated with enhanced survival in macrophage-like cells.

In Germany, a clonal line of Salmonella Saintpaul with a multidrug resistant phenotype was found in turkeys and human feces. These isolates exhibited resistance (either complete or intermediate) to ampicillin, amoxicillin-clavulanic acid, gentamicin, kanamycin, nalidixic acid, streptomycin, spectinomycin, and sulfamethoxazole, along with intermediate resistance or reduced susceptibility to ciprofloxacin and multiple third-generation cephalosporins (including ceftiofur and cefoxitin). Genotypic analysis revealed a conserved resistance pattern, featuring bla_TEM-1, aadB, aadA2, sul1, and a Ser83→Glu83 mutation in the gyrA gene. Additionally, all isolates carried a chromosomal class 1 integron harboring the aadB-aadA2 gene cassette.

Animal reservoir: Unknown, but turkey and swine are likely to be reservoirs for serovar Saintpaul. 

Geographical distribution: This serovar is globally distributed. Serovar Saintpaul ranks among the top ten most prevalent non-typhoidal Salmonella (NTS) serovars globally, causing approximately 1.6% of severe human infections despite over 1,400 known NTS serovars. Between 2011 and 2020, serovar Saintpaul was one of the 10 most frequently isolated Salmonella serovars in Brazil, accounting for 1,222 cases (0.16% of 62,030 isolates). In the Northern territory of Australia, it was the third most frequently reported serovar in 2014, representing 11% of all reported salmonellosis cases. 

Human outbreaks: Multiple human outbreaks associated with serovar Saintpaul have been reported, linked to a variety of commodities. Below are some examples.

¹ Serovar Javiana and Rubislaw were also involved. The case number here does not reflect the total number of people only infected by Salmonella Saintpaul.

Border rejections: Multiple border rejections linked to serovar Saintpaul have been reported. A majority of these border rejections were associated with black pepper imported from Brazil to Germany and identified multiple Salmonella serovars including serovar Sainpaul. Below are some examples.

¹ Salmonella Poona, Javiana and Saintpaul were found.  

² Salmonella Infantis, Freetown, Javiana, and Saintpaul were found. 

³ Salmonella Saintpaul and Javiana were found. 

⁴ Salmonella Derby and Saintpaul were found. 

Recalls:

¹ This recall was caused by a multistate outbreak described above. Agricola Zaragoza, Inc. of McAllen, TX issued a recall of their Jalapeno peppers. 

Relevant links:

1. https://www.jstor.org/stable/30092155?seq=2
2. https://journals.asm.org/doi/10.1128/msphere.00730-21
3. https://pubmed.ncbi.nlm.nih.gov/20363784/
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC2876473/
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC11942379/
6. https://pubmed.ncbi.nlm.nih.gov/8774669/
7. https://www.cdc.gov/salmonella/outbreaks/index.html
8. https://www.clinicalcasereportsint.com/open-access/top-10-salmonella-serovars-associated-with-human-salmonellosis-in-brazil-2011-2020-8688.pdf
9. https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-cdi4101k.htm
10. https://www.foodpoisoningnews.com/mystery-salmonella-outbreak-hospitalizes-five-sickens-25-across-uk/
11. https://pubmed.ncbi.nlm.nih.gov/38705587/
12. https://www.ksl.com/article/41279440/salmonella-outbreak-linked-to-raw-milk-sold-in-midway
13. https://www.foodsafetynews.com/2021/11/salmonella-top-cause-of-foodborne-outbreaks-in-australia/
14. https://archive.cdc.gov/www_cdc_gov/salmonella/saintpaul-04-13/index.html
15. https://archive.cdc.gov/www_cdc_gov/salmonella/2009/raw-alfalfa-sprouts-5-8-2009.html
16. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5734a1.htm
17. https://www.jstor.org/stable/25476916?seq=1
18. https://pubmed.ncbi.nlm.nih.gov/11190815/
19. https://pubmed.ncbi.nlm.nih.gov/8557082/#:~:text=Between%20April%20and%20September%201993,were%20found%20in%20the%20snacks.
20. https://webgate.ec.europa.eu/rasff-window/screen/notification/616717
21. https://webgate.ec.europa.eu/rasff-window/screen/notification/521476
22. https://webgate.ec.europa.eu/rasff-window/screen/notification/452713
23. https://webgate.ec.europa.eu/rasff-window/screen/notification/452474
24. https://webgate.ec.europa.eu/rasff-window/screen/notification/423533
25. https://webgate.ec.europa.eu/rasff-window/screen/notification/618965
26. https://web.archive.org/web/20090710090159/http://www.fda.gov/Safety/Recalls/ArchiveRecalls/2008/ucm112471.htm