S. Bochum¶

At a Glance


Antigenic Formula	`1,4,[5],12:r:l,w`
Serogroup	O:4 (B)
NCBI Pathogen Detection	View isolates

Background Information¶

Salmonella enterica subsp. enterica serovar Bochum (antigenic formula 1,4,[5],12:r:l,w) is a serovar of the O:4 (B) serogroup. It was named after Bochum, an industrial city in the Ruhr region of North Rhine-Westphalia, Germany. Serovar Bochum is a relatively uncommon serovar globally and is rarely implicated in large-scale foodborne illness outbreaks. Like other Group B serovars, it shares the O:4 somatic antigen and is capable of causing gastroenteritis in humans following consumption of contaminated food or water, or through direct contact with colonized animals.

Genetic Characteristics¶

Serovar Bochum belongs to clade A of Salmonella enterica, according to the den Bakker et al. (2011) phylogenetic classification. Like other Group B serovars, serovar Bochum carries the core somatic antigen determinants associated with O:4, encoded by genes within the rfb locus on the chromosome. The phase 1 flagellar antigen r is encoded by the fliC gene, and the phase 2 antigen l,w is encoded by the fljB gene; expression of these two phases alternates through a site-specific DNA inversion mechanism known as flagellar phase variation.

Animal Reservoir¶

Serovar Bochum has been isolated from multiple animal species, including poultry, cattle, and swine, which serve as environmental reservoirs for this serovar. Contaminated feed and water sources can facilitate its persistence and spread within animal production environments.

Geographical Distribution¶

Serovar Bochum has been reported worldwide, though its overall prevalence remains low relative to dominant Group B serovars such as Salmonella Typhimurium. Isolates have been detected across Europe, North America, and other regions, primarily from animal and environmental surveillance programs.

Human Outbreaks¶

Year	Location	Associated source	Number of cases
2025-2026	Germany	RKI outbreak notice	40

Animal Outbreaks¶

There have been no recent animal outbreaks linked to this serovar.

Border Rejections¶

There have been no border rejections linked to Salmonella Bochum documented in publicly available sources.

Recalls¶

There have been no recalls linked to Salmonella Bochum documented in publicly available sources.