PhD opportunity: ESBL Risk to Farm Workers

ESBL-producing E. coli have been shown to be present in farmed animals, especially in dairy cows, where the use of cephalosporins for the treatment of mastitis is common. Zoonotic spread of antimicrobial resistance is of concern and there is the potential for this either via direct contact between animals and people or via the food chain. However, the extent to which food animals act as a reservoir of resistant bacteria or resistance determinants, the frequency of transmission, and therefore the risk to public health is not known. We propose to use farm workers and their households as sentinels for transmission from food animals. We hypothesise that individuals who have close and frequent contact with food animals will have a greater risk of carriage of ESBL-producing bacteria, which are present in food animals. There is currently a paucity of data available on the faecal carriage rate and risk factors for individuals who have frequent contact with food animals or who live on farms.

We will achieve this through cross-sectional surveys of cattle farmers, farm workers and resident households. We will also conduct a nested case-control study to determine risk factors for ESBL carriage, including the presence of such bacteria in the cattle on farms, from a selection of farms where the farmers were positive and negative for ESBL-producing bacterial. In addition, a subset of farms where animals are positive for ESBL-producing bacteria will be followed longitudinally to inform the frequency of transmission between animals and in-contact individuals. This will allow us to determine if carriage in animals is a risk factor for carriage in people, and if animals carry the same strains or resistance determinants as workers/household members positive on such farms.

This project will allow an approximation of risk of carriage in individuals with regular food animal contact, furthermore from the farm households we may also be able to determine household spread and transmission. It will determine whether farm workers and their families, are an at risk group for carriage and transmission within households or the community and what interventions may be considered to mitigate this risk, at the farm level. It will also inform on the potential reservoir and likelihood of food animals as a reservoir of such bacteria and the risk of transfer via the food chain.

This work will be undertaken within the Institute of Infection and Global Health at the University of Liverpool, by a team who has extensive experience of conducting such studies, as well as surveys on ESBL-producing bacteria, and consists of microbiologists, clinicians (human and veterinary) and epidemiologists. Isolates and resistance determinants from these studies will also be fully characterised. This will allow us to determine whether such strains and determinants are similar to those prevalent currently in human and animal clinical isolates.

The main aim of this study is to determine the carriage rate and risk factors for faecal carriage of ESBL-producing bacteria in those working with farmed animals and their households. Furthermore, such data will inform on transmission rates of resistant bacteria and their resistance determinants, which are vital to informing risk analysis. Samples collected from these studies will also support further work to investigate the presence of zoonotic enteric pathogens, such as Campylobacter spp and enterpathogenic E. coli in farmers and those resident on farms.

Please email your application to:

This should consist of two documents attached as PDFs; a CV and a covering letter. Please limit your CV to three pages and state in your covering letter the title of the PhD you are applying for. Do not attach any other documents. The subject heading of the email should only state ‘HPRU PhD application 2015’. Candidates shortlisted for interview will be informed in due course. Please note we are only recruiting UK/EU/home rated students and only eligible students should apply.

Funding Notes

This PhD studentship is for three years and provides a full stipend.

Potential students must be highly motivated and in possession of or about to receive an honours degree in a relevant discipline with either a 2.1 or 1st. A 2.2 honours degree will only be acceptable for students who go on to achieve a Distinction in a relevant Masters programme.