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Background: Salmonella enterica subsp. enterica serovar I 4,[5],12:b:- (antigenic formula 1,4,[5],12:b:-) is a serovar of the O:4 (B) serogroup. This serovar is monophasic which doesn't express phase 2 flagellar antigen. Serovar I 4,[5],12:b:- might be the monophasic variant of serovar Paratyphi B, as they only differ in the H₂ antigen. This serovar has been documented as a fluctuating serovar in broiler flocks and has been identified in poultry slaughterhouses in Spain and Denmark. It is also sporadically isolated from human gastroenteritis cases.

NCBI PD link for serovar I 4,[5],12:b:-: https://www.ncbi.nlm.nih.gov/pathogens/isolates/#(taxgroup_name:%22Salmonella%20enterica%22)%20AND%20computed_types:(%22serotype=I%204:b:-%22)

Genetic characteristics:

Animal reservoir: Chicken may be the primary reservoir of serovar I 4,[5],12:b:-; however, this serovar has also been isolated from horses in the past.

Geographical distribution: Serovar I 4,[5],12:b:- has been report in Australia, China, Ghana, Europe, and North America including the US and Canada.

Human outbreaks:

Year	Location	Associated source	Number of cases
2018	US: multistate	Kratom powder¹	61
2018	US: multistate, Canada	Shredded Frozen Coconut²	26

¹ This outbreak was also associated with Salmonella Javiana, Okatie, and Thompson. The case number here applies exclusively to infections caused by Salmonella I 4,[5],12:b:-.

² This outbreak also involved Salmonella Newport. The case number here applies exclusively to infections caused by Salmonella I 4,[5],12:b:-.

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

Recalls:

Year	Location	Recalled food	Type
2018	US: multistate	Kratom¹	Other food product / mixed

¹ The recall was prompted by the multistate outbreak described above. The FDA has compiled a full list of recalled kratom products, but it is currently unavailable.

Relevant links: