Whole-genome sequencing of Campylobacter jejuni isolated from Danish routine human stool samples reveals surprising degree of clustering

TY - JOUR

T1 - Whole-genome sequencing of Campylobacter jejuni isolated from Danish routine human stool samples reveals surprising degree of clustering

AU - Joensen, K. G.

AU - Kuhn, K. G.

AU - Müller, L.

AU - Björkman, J. T.

AU - Torpdahl, M.

AU - Engberg, J.

AU - Holt, H. M.

AU - Nielsen, H. L.

AU - Petersen, A. M.

AU - Ethelberg, S.

AU - Nielsen, E. M.

PY - 2018

Y1 - 2018

N2 - Objectives: Outbreaks of Campylobacter are traditionally considered to be rare; however, rather than being the true nature of the disease, this may reflect our present inability to detect them. The aim of this study was to determine the genetic and epidemiological degree of clustering among Campylobacter jejuni isolates from Danish patients. Methods: Whole-genome sequencing (WGS) was applied to 245 C. jejuni isolates from patients with domestically acquired infection over a 9-month period in 2015 and 2016. Results: WGS demonstrated that 62 of the 245 isolates (25%) clustered genetically. In total, 21 genetic clusters were identified of which four (18%) consisted of five isolates or more. Seventeen (81%) of the 21 genetic clusters were clustered in space and/or time. Of the 245 isolates, 49 (20%) were part of a temporal and/or geographical cluster. The identified clusters included two outbreaks; one which had not been identified through the existing surveillance system. Conclusions: Using WGS, we show that Campylobacter case clustering and even outbreaks appear to occur more often than previously assumed, providing important new insight into the relatively poorly understood epidemiology of the most important cause of bacterial gastroenteritis in the industrialized world.

AB - Objectives: Outbreaks of Campylobacter are traditionally considered to be rare; however, rather than being the true nature of the disease, this may reflect our present inability to detect them. The aim of this study was to determine the genetic and epidemiological degree of clustering among Campylobacter jejuni isolates from Danish patients. Methods: Whole-genome sequencing (WGS) was applied to 245 C. jejuni isolates from patients with domestically acquired infection over a 9-month period in 2015 and 2016. Results: WGS demonstrated that 62 of the 245 isolates (25%) clustered genetically. In total, 21 genetic clusters were identified of which four (18%) consisted of five isolates or more. Seventeen (81%) of the 21 genetic clusters were clustered in space and/or time. Of the 245 isolates, 49 (20%) were part of a temporal and/or geographical cluster. The identified clusters included two outbreaks; one which had not been identified through the existing surveillance system. Conclusions: Using WGS, we show that Campylobacter case clustering and even outbreaks appear to occur more often than previously assumed, providing important new insight into the relatively poorly understood epidemiology of the most important cause of bacterial gastroenteritis in the industrialized world.

KW - Campylobacter

KW - Clustering

KW - Outbreaks

KW - Surveillance

KW - Whole-genome-sequencing

U2 - 10.1016/j.cmi.2017.07.026

DO - 10.1016/j.cmi.2017.07.026

M3 - Letter

C2 - 28782648

AN - SCOPUS:85029678260

SN - 1198-743X

VL - 24

SP - 201.e5-201.e8

JO - Clinical Microbiology and Infection

JF - Clinical Microbiology and Infection

IS - 2

ER -