S. Concord¶

At a Glance


Antigenic Formula	`6,7:l,v:1,2`
Serogroup	O:7 (C1)
NCBI Pathogen Detection	View isolates

Background Information¶

Salmonella enterica subsp. enterica serovar Concord (antigenic formula 6,7:l,v:1,2) is a serovar of the O:7 (C₁) serogroup. Serovar Concord was first isolated from poultry in the US in 1944. Vanhoof et al. demonstrated that transmission of Salmonella Concord, both within and outside families, can occur, although the frequency appears to be relatively low.

Genetic Characteristics¶

Serovar Concord has been found to be polyphyletic with three lineages identified and one stand-alone singleton that does not cluster with any other Salmonella Concord isolates. Beyene et al. showed that MDR Concord isolates are associated with salmonellosis in children in Ethiopia. Among 81 serovar Concord isolates they analyzed, 30% were invasive, with the majority (86.5%) testing positive for ESBL production via E-test. Additionally, 70% exhibited multidrug resistance to trimethoprim-sulfamethoxazole, ceftriaxone, chloramphenicol, and gentamicin. Of these, more than a quarter (27%) also demonstrated reduced susceptibility to ciprofloxacin. Vanhoof et al. confirmed the emergence of Salmonella Concord isolates in Europe that are resistant to third-generation cephalosporins among Ethiopian adoptees. Morosini et al. documented, from the stool cultures of an Ethiopian child in Madrid, the persistent recovery of CTX-M-15- and SHV-12-harbouring Concord strains, which also carry QnrA1. By studying genomes from 284 historical and contemporary isolates obtained worldwide between 1944 and 2022, Cuypers et al.found serovar Concord is a polyphyletic serovar, distributed across three Salmonella super-lineages. Super-lineage A comprises eight distinct Concord lineages, four of which are found in multiple countries and exhibit low levels of antimicrobial resistance (AMR). The remaining lineages are primarily confined to Ethiopia and have acquired resistance horizontally to most antimicrobials commonly used to treat invasive Salmonella infections in low- and middle-income countries.

Animal Reservoir¶

Chicken may be the potential reservoir of serovar Concord.

Geographical Distribution¶

Serovar Concord has been reported worldwide.

Human/Animal Outbreaks¶

Year	Location	Associated source	Number of cases
2018-2019	US: multistate	Tahini	8

Border Rejections¶

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

Recalls¶

Year	Location	Recalled food	Type
2018	US: multistate	Tahini¹	RTE Product

¹ Achdut Ltd. in Ari’el, Israel recalled their tahini products. This recall was caused by a multistate outbreak described above.