S. Paratyphi B¶

At a Glance


Antigenic Formula	`1,4,[5],12:b:1,2`
Serogroup	O:4 (B)
NCBI Pathogen Detection	View isolates

Background Information¶

Salmonella enterica subsp. enterica serovar Paratyphi B (antigenic formula 1,4,[5],12:b:1,2) is a serovar of the O:4 (B) serogroup. The classification scheme of serovar Paratyphi B has changed over time since infections associated with this serovar were first reported in the late 1800s. Serovar Paratyphi B can be classified by its ability to ferment tartrate. Serovar Paratyphi B (tartrate negative) is associated with paratyphoid fever and infections with this serovar are not common in the US. Serovar Paratyphi B (tartrate positive), formerly serovar Java, is associated with gastroenteritis and can also be written as serovar Paratyphi B var. L(+) tartrate+. Serovar Paratyphi B has also been found in some animals such as dogs and in pet fish tanks.

Genetic Characteristics¶

Serovar Paratyphi B has been found to be polyphyletic with four lineages identified. A study of 568 isolates found that antimicrobial resistance is fairly recent for this serovar and is mostly related to resistance to quinolones. Serovar Paratyphi B sequence type 28has been highly found in poultry from Europe and Latin America with resistance to beta-lactams and quinolones.

Animal Reservoir¶

Serovar Paratyphi B is almost exclusively host restricted to humans and closely related anthropoids.

Geographical Distribution¶

Serovar Paratyphi B is widely distributed and had been reported in North America (US, Canada, Mexico), South America (Brazil, Colombia), Europe (UK, France, Denmark), Africa (Nigeria, Zimbabwe), Asia (India, South Korea, Japan), and Australia.

Human/Animal Outbreaks¶

Several outbreaks have been associated with S. Paratyphi B.

Year	Location	Associated source	Number of cases
2015	US: Multistate	Sprouted nut butter spread	13
2015	US: Multistate	Frozen raw tuna	65
2012	US: Multistate	Tempeh	63
1999	Canada	Alfalfa sprouts	51
1986	UK	Food Handler	3

Border Rejections¶

Year	Exporting country	Importing country	Associated source	Product category
2024	Germany	Italy	Frozen chicken leg	Poultry meat and poultry meat products
2023	Netherlands	Italy	Frozen chicken mince	Poultry meat and poultry meat products
2021	Netherlands	Italy	Chicken drumsticks	Poultry meat and poultry meat products

Recalls¶

Year	Location	Recalled food	Type
2015	US: Multistate	Sprouted nut butter spread	Other food product
2012	US: Multistate	Tempeh	Other food product