S. Blockley¶

At a Glance


Antigenic Formula	`6,8:k:1,5`
Serogroup	O:8 (C2-C3)
NCBI Pathogen Detection	View isolates

Background Information¶

Salmonella enterica subsp. enterica serovar Blockley (antigenic formula 6,8:k:1,5) is a serovar of the O:8 (C₂-C₃) serogroup. Serovar Blockley was first isolated from the stool from a 60-year-old patient in the United States in 1955. This serovar was involved in a case of cardiac device infection in China. Interestingly, serovar Blockley was suggested to be associated with long-term reactive arthritis. Serovar Blockley was among the five most common isolated serotypes from both avian and human sources in Japan, Thailand, and Malaysia.

Genetic Characteristics¶

Serovar Blockley has been found to be polyphyletic with three lineages identified. Izumiya et al. found that 264 Blockley isolates can be classified to 10 distinct groups (BAPS A to BAPS J), further categorized into two lineages, R and S. Lineage R was made of six BAPS clusters (BAPSs A-F), primarily found in Africa and Asia, all of which possessed the azithromycin resistance gene mph(A) and other resistance patterns. Lineage R was found to harbor a genomic island with mph(A), aph(3')-Ia, aph(3")-Ib, aph(6)-Id, and tet(A).

Animal Reservoir¶

Chickensare the main reservoir for serovar Blockley. This serovar was also found in turkey, cattle, and pigs.

Geographical Distribution¶

Serovar Blockley has been reported worldwide periodically.

Human/Animal Outbreaks¶

Year	Location	Associated source	Number of cases
2019	US: NY	Chicken	10
1998	Germany	Smoked eel	13
1998	Greece	Unknown	35
1966	US: MA	Frozen unpasteurized egg yolks	167

S. Blockley¶

Background Information¶

Genetic Characteristics¶

Animal Reservoir¶

Geographical Distribution¶

Human/Animal Outbreaks¶

Border Rejections¶

Recalls¶

References¶