Spread of avian pathogenic Escherichia coli ST117 O78:H4 in Nordic broiler production

BMC Genomics

Research Article

Rikke Heidemann Olsen¹  Tarja Pohjanvirta²  Ulrike Lyhs³  Troels Ronco³  Karl Pedersen³  Camilla Sekse⁴  Anne Bang Nordstoga⁴  Marc Stegger⁵  Berit Lilje⁵  Paal Skytt Andersen⁵ 

[1] Department of Veterinary Disease Biology, University of Copenhagen, Stigbøjlen 4, 1870, Frederiksberg C, Denmark;Finnish Food Safety Authority, Veterinary Bacteriology, Neulaniementie 4, FI-70210, Kuopio, Finland;National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1870, Frederiksberg C, Denmark;Norwegian Veterinary Institute, Ullevaalsveien 68, 0454, Oslo, Norway;Statens Serum Institut, Department of Microbiology and Infection Control, Artillerivej 5, 2300, Copenhagen S, Denmark;

关键词: APEC;    Colibacillosis;    Comparative genomics;    Phylogenetic analysis;    Virulence factors;   

DOI  :  10.1186/s12864-016-3415-6

 received in 2016-09-14, accepted in 2016-12-12,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundEscherichia coli infections known as colibacillosis constitute a considerable challenge to poultry farmers worldwide, in terms of decreased animal welfare and production economy. Colibacillosis is caused by avian pathogenic E. coli (APEC). APEC strains are extraintestinal pathogenic E. coli and have in general been characterized as being a genetically diverse population. In the Nordic countries, poultry farmers depend on import of Swedish broiler breeders which are part of a breeding pyramid. During 2014 to 2016, an increased occurrence of colibacillosis on Nordic broiler chicken farms was reported. The aim of this study was to investigate the genetic diversity among E. coli isolates collected on poultry farms with colibacillosis issues, using whole genome sequencing.MethodsHundred and fourteen bacterial isolates from both broilers and broiler breeders were whole genome sequenced. The majority of isolates were collected from poultry with colibacillosis on Nordic farms. Subsequently, comparative genomic analyses were carried out. This included in silico typing (sero- and multi-locus sequence typing), identification of virulence and resistance genes and phylogenetic analyses based on single nucleotide polymorphisms.ResultsIn general, the characterized poultry isolates constituted a genetically diverse population. However, the phylogenetic analyses revealed a major clade of 47 closely related ST117 O78:H4 isolates. The isolates in this clade were collected from broiler chickens and breeders with colibacillosis in multiple Nordic countries. They clustered together with a human ST117 isolate and all carried virulence genes that previously have been associated with human uropathogenic E. coli.ConclusionsThe investigation revealed a lineage of ST117 O78:H4 isolates collected in different Nordic countries from diseased broilers and breeders. The data indicate that the closely related ST117 O78:H4 strains have been transferred vertically through the broiler breeding pyramid into distantly located farms across the Nordic countries.

【 授权许可】

CC BY   
© The Author(s). 2017