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A laboratory study to assess the potential for transfer of antibiotic resistance between bacterial strains - OD2005

Description
This proposal aims to addrress para81A of the MAFF Animal Health and Welfare Research Requirements Document May 1999, `What is the potential for transfer of antimirobial resistance between different bacterial strains/specie in stored and spread organic wastes`.

The first year of the project will invole laboratorystudies, in which model bacterial strains possessing transferable antibiotic such as oxytetracycline, sulphamezathine and tylosin, will be sought. We will then use the resistant strains in laboratory microcosms to model storage and spread of wastes. Microcosms will contain wastes alone, held at various temperatures to model storage, and wastes mixed with soil, held at various temperatures to model spreading and seasonal variation. The fate of the rates of transfer will be determined in each scenario under different conditions. The possibility of transfer of resistance to salmonellae will also be studied in the microcosms.

In the second year of the project, the fate and behaviour of the model strains in pig slurry stored in the farm will be modeled. This will be done using simple semipermeable bags containing seeded slurry suspended in pig waste and kept in situ at the farm. The fate and behaviour of the model strains in amended soil will be studied using soil lysimeters. Seeded pig waste will be applied to the lysimeters in summer, and samples taken over one year.

The study will provide quantitative information regarding the potential for gene transfer in stored and spread farm wastes, and the factors which influence it. This will assist the Ministrry to produce risk assesments in keeping with the policy of reducing the risk to public health from antimicrobial resistance arising from the use antimicrobial products in domestic livestock.
Objective
1- To select suitable mating models for use in subsequent experiments, ideally by isolating and characterising pig gut-commensal bacterial strains (e.g. Lactobacillus, Enterococcus) possessing transferable antibiotic resistance(s), from organic farm wastes (31/8/2000)

2- In closed laboratory systems, or microcosms, examine the rates of transfer when the model strains are incubated in manure and slurry stored at various temperatures (31/3/2001)

3- To determine occurence and rates of transfer of resistances from the resistant commensal bacteria to Salmonella typhimurium, a human pathogenic bacterium (31/3/2001)

4- To determine rates of transfer between the modal strains, and their persistence, in pig slurry stored in situ on the farm (31/3/2002)

5- To determine rates of transfer from resistant commensal bacteria to Salmonela typhimurium in pig slurry stored in situ on the farm (31/3/2002)

6- To determine rates of transfer between the modal strains, and their persistence, in pig slurry-amended soil contained in field lysimeters (31/07/2003)

7- To determine rates of transfer from resistant commensal bacteria to Salmonella typhiurium in pig slurry- amended soil contained in field lysimeters (31/07/2003)
Project Documents
• Final Report : A laboratory study to assess the potential for transfer of antibiotic resistance between bacterial strains   (1561k)
Time-Scale and Cost
From: 2000

To: 2003

Cost: £272,887
Contractor / Funded Organisations
Central Science Laboratory
Keywords
Animal Diseases              
Animal Health              
Antimicrobial Resistance              
Bacteria              
Biotechnology              
E.coli O157              
Pigs              
Plants and Animals              
Salmonella              
Fields of Study
Animal Health