A molecular epidemiological study on Escherichia coli in young chicks with colibacillosis identified two possible outbreaks across farms

Veterinary Research

Research Article

Marina Aspholm¹  Siri Kulberg Sjurseth²  Bruce David²  Camilla Sekse³  Inger Helene Kravik³  Katharine Rose Dean³  Håkon Kaspersen³ 

[1] Faculty of Veterinary Medicine, The Norwegian University of Life Sciences, Postboks 5003, 1432, Ås, Norway;Nortura SA, P.O. Box 360, Økern, 0513, Oslo, Norway;Norwegian Veterinary Institute, Ås, Norway;

关键词: Escherichia coli;    colibacillosis;    poultry;    whole genome sequencing;    virulence-associated genes (VAGs);    outbreak;    systematic sampling;   

DOI  :  10.1186/s13567-023-01140-6

 received in 2022-11-15, accepted in 2023-01-13,  发布年份 2023

来源: Springer

【 摘 要 】

Avian pathogenic Escherichia coli (APEC) is the cause of colibacillosis outbreaks in young poultry chicks, resulting in acute to peracute death. The high morbidity and mortality caused by colibacillosis results in poor animal welfare, reduced sustainability and economical loss worldwide. To advance the understanding of the molecular epidemiology, genomic relatedness and virulence traits of APEC, we performed systematic sampling from 45 confirmed colibacillosis broiler flocks with high first week mortality (FWM) during 2018–2021. From these flocks, 219 APEC isolates were whole genome sequenced (WGS) and bioinformatic analyses were performed. The bioinformatic analyses included sequence typing (ST), serotyping, detection of virulence-associated genes (VAGs) and phylogenetic analysis. Our results showed a high prevalence of ST23, ST429 and ST95 among APEC isolates from Norwegian broiler flocks, and identified ST23, ST429, ST117 and ST371 to cause disease more often alone, compared to ST95, ST69 and ST10. Phylogenetic analyses, together with associated metadata, identified two distinct outbreaks of colibacillosis across farms caused by ST429 and ST23 and gave insight into expected SNP distances within and between flocks identified with the same ST. Further, our results highlighted the need for combining two typing methods, such as serotyping and sequence typing, to better discriminate strains of APEC. Ultimately, systematic sampling of APEC from multiple birds in a flock, together with WGS as a diagnostic tool is important to identify the disease-causing APEC within a flock and to detect outbreaks of colibacillosis across farms.

【 授权许可】

CC BY   
© The Author(s) 2023

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