TY - JOUR
T1 - Whole genome sequencing improved case ascertainment in an outbreak of Shiga toxin-producing Escherichia coli O157 associated with raw drinking milk
AU - Butcher, H.
AU - Elson, Richard
AU - Chattaway, Marie Anne
AU - Featherstone, C. A.
AU - Willis, Caroline
AU - Jorgensen, Frieda
AU - Dallman, Tim
AU - Jenkins, Claire
AU - McLauchlin, James
AU - Beck, Charles
AU - Harrison, S.
N1 - Publisher Copyright:
© Cambridge University Press 2016.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Five cases of STEC O157 phage type (PT) 21/28 reported consumption of raw cows' drinking milk (RDM) produced at a dairy farm in the South West of England. STEC O157 PT21/28 was isolated from faecal specimens from milking cows on the implicated farm. Whole genome sequencing (WGS) showed that human and cattle isolates were the same strain. Further analysis of WGS data confirmed that sequences of isolates from an additional four cases (who did not report consumption of RDM when first questioned) fell within the same five single nucleotide polymorphism cluster as the initial five cases epidemiologically linked to the consumption of RDM. These four additional cases identified by WGS were investigated further and were, ultimately, associated with the implicated farm. The RDM outbreak strain encoded stx2a, which is associated with increased pathogenicity and severity of symptoms. Further epidemiological analysis showed that 70% of isolates within a wider cluster containing the outbreak strain were from cases residing in, or linked to, the same geographical region of England. During this RDM outbreak, use of WGS improved case ascertainment and provided insights into the evolution of a highly pathogenic clade of STEC O157 PT21/28 stx2a associated with the South West of England.
AB - Five cases of STEC O157 phage type (PT) 21/28 reported consumption of raw cows' drinking milk (RDM) produced at a dairy farm in the South West of England. STEC O157 PT21/28 was isolated from faecal specimens from milking cows on the implicated farm. Whole genome sequencing (WGS) showed that human and cattle isolates were the same strain. Further analysis of WGS data confirmed that sequences of isolates from an additional four cases (who did not report consumption of RDM when first questioned) fell within the same five single nucleotide polymorphism cluster as the initial five cases epidemiologically linked to the consumption of RDM. These four additional cases identified by WGS were investigated further and were, ultimately, associated with the implicated farm. The RDM outbreak strain encoded stx2a, which is associated with increased pathogenicity and severity of symptoms. Further epidemiological analysis showed that 70% of isolates within a wider cluster containing the outbreak strain were from cases residing in, or linked to, the same geographical region of England. During this RDM outbreak, use of WGS improved case ascertainment and provided insights into the evolution of a highly pathogenic clade of STEC O157 PT21/28 stx2a associated with the South West of England.
KW - Bacterial typing
KW - Escherichia coli
KW - foodborne infections
KW - gastrointestinal infections
KW - public health microbiology
UR - http://www.scopus.com/inward/record.url?scp=84988535383&partnerID=8YFLogxK
U2 - 10.1017/S0950268816000509
DO - 10.1017/S0950268816000509
M3 - Article
C2 - 27338677
AN - SCOPUS:84988535383
VL - 144
SP - 2812
EP - 2823
JO - Epidemiology and Infection
JF - Epidemiology and Infection
SN - 0950-2688
IS - 13
ER -