University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Lactobacilli probiotics as a potential control for avian intestinal spirochaetosis.

Passey, Jade L. (2019) Lactobacilli probiotics as a potential control for avian intestinal spirochaetosis. Post-Doctoral thesis, University of Surrey.

[img] Text
Jade Louise Passey_Thesis_Final Jan 2019.pdf - Version of Record
Restricted to Repository staff only until 31 January 2020.
Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (14MB) | Request a copy
[img] Text
RestrictingAccessThesisForm_JadePassey.docx - Supplemental Material
Restricted to Repository staff only
Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (280kB) | Request a copy

Abstract

Brachyspira are the causative agent of avian intestinal spirochaetosis, a gastrointestinal disease common in layer hens and broiler breeders. This disease costs the UK laying industry approximately £18 million per annum, resulting from reduced egg production and poor egg quality. Prevalence of Brachyspira is increasing, and due to the poor understanding of this pathogen, mitigation strategies have been largely unsuccessful. Therefore, preventative measures are essential. These studies aimed to improve the understanding of Brachyspira pathobiology and investigate Lactobacillus probiotics as a suitable mitigation strategy. Brachyspira and Lactobacillus species were characterised using phenotypic and genotypic methods. Four Lactobacillus isolates were selected for their inhibition of Brachyspira in vitro and demonstrated inhibition by a number of mechanisms. Secreted metabolites in Lactobacillus cell free supernatant inhibited Brachyspira (p value < 0.05) and metabolomic studies identified the production of organic acids to be a major contributor to inhibition. Protein denaturation in cell free supernatants significantly reduced Brachyspira inhibition (p value < 0.05), suggesting the role of bacteriocins in inhibition. Furthermore, L. reuteri isolates co-aggregated with Brachyspira in vitro, reducing pathogen viability (p value < 0.05). Pro-inflammatory responses to Brachyspira in HD11 avian macrophages were dominated by upregulation of IFNg (p value < 0.01) and pre-treatment of cells with Lactobacillus significantly reduced this response (p value < 0.0001), demonstrating the ability of probiotics to alter immune responses to Brachyspira. Galleria mellonella were utilised to study Brachyspira virulence and probiotic intervention. G. mellonella exhibited a varied response to Brachyspira iv infection and Lactobacillus isolates were able to protect against the mortality associated with Brachyspira isolates (p value < 0.05). The studies here demonstrated that Lactobacillus probiotics are a suitable mitigation strategy against Brachyspira. A number of mechanisms were identified, however future studies are required to explore these mechanisms in a more relevant in vivo chicken model.

Item Type: Thesis (Post-Doctoral)
Divisions : Theses
Authors :
NameEmailORCID
Passey, Jade L.https://orcid.org/0000-0002-0260-281X
Date : 31 January 2019
Funders : British Egg Marketing Board
DOI : 10.15126/thesis.00850126
Contributors :
ContributionNameEmailORCID
http://www.loc.gov/loc.terms/relators/THSLa Ragione, RobertoR.Laragione@surrey.ac.uk
http://www.loc.gov/loc.terms/relators/THSGutierrez, Jorgej.gutierrez@surrey.ac.uk
http://www.loc.gov/loc.terms/relators/THSWoodward, Martinm.j.woodward@reading.ac.uk
Depositing User : Jade Passey
Date Deposited : 07 Feb 2019 09:21
Last Modified : 07 Feb 2019 09:22
URI: http://epubs.surrey.ac.uk/id/eprint/850126

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800