PhD Study : Filter feeding and antibiotic resistance in aquatic environments

Summary

The emergence of superbugs as bacteria with resistance against many different antibiotics, is recognised by the World Health Organisation as a global health crisis. While their increased frequency of occurrence is well documented in medical health care, the understanding of contributing factors in natural environments remains sketchy, yet is considered to be a central factor in the dissemination of these pathogens (Berendonk et al., 2015). Aquatic ecosystems receive transfers of antibiotics, their residues, resistant bacteria and their resistance genes from multiple sources. Lupo et al. (2012) had suggested that filter feeding could be a natural process with a contribution to the emergence and dissemination of multiple antibiotic resistance in water environments.

Experimental evidence suggests that crustacean zooplankton populations can retain resistance genes from ingested bacteria in their gut flora (Eckert et al., 2016). Short term retention but not accumulation of such genes has also been observed in seawater clams (Suzuki et al., 2018). Recently, microcosm experiments have demonstrated that aquatic filter feeding can increase rates of antibiotic resistance transfer and the dissemination of transconjugant bacteria (Olanrewaju et al., 2019; Strachan, 2019); however this is apparently not a universal property (Cartwright et al., 2020) and may depend on a complex interplay between bacterial species, specific characteristics of filter feeders and conditions in the ambient environment.

This project aims to assess the role of aquatic filter feeders further in regard to their potential roles in facilitating the accumulation of antibiotic resistance genes, their horizontal transfer and their dissemination.

Research objectives:

1. Microcosm investigations of the facilitation of the horizontal transfer of antibiotic resistance by aquatic filter feeders.
2. Mesocosm investigations with environmentally relevant abundances of filter feeders and bacteria.
3. Investigation of the persistence of multi resistant bacteria in filter feeders and the potential transfer to predators of these organisms.
4. Laboratory investigations of the intergenerational persistence of the resistome in filter feeders.
5. Field investigations of the resistome in populations of filter feeders.
6. Field studies of the resistome in sediments subject to transfers from filter feeding organisms

Methodology:

The investigation will employ methods of hydrobiology (microcosm studies of filtration rates, mesocosm studies), classical microbiology (e.g. resistance profiles) and molecular biology (e.g. q-PCR and metagenomics).

Impact:

This project supports the One Health initiative (Health-NI, n.d.) which coordinates efforts across the Health, Agriculture, Food, Environmental and Industrial sectors to tackle antibiotic resistance. It will inform strategies for the antibiotic resistance monitoring in aquatic environments with a focus on sediments and thus contributes towards improved targeting of mitigation measures. Furthermore, the investigation of aquatic organisms, which concentrate waterborne bacteria, and food chain effects will yield relevant information for food safety.

There are opportunities for collaboration with a DAERA funded pilot project on antimicrobial residues in regional waters.

References will be requested for shortlisted candidates.

Essential criteria

Applicants should hold, or expect to obtain, a First or Upper Second Class Honours Degree in a subject relevant to the proposed area of study.

We may also consider applications from those who hold equivalent qualifications, for example, a Lower Second Class Honours Degree plus a Master’s Degree with Distinction.

In exceptional circumstances, the University may consider a portfolio of evidence from applicants who have appropriate professional experience which is equivalent to the learning outcomes of an Honours degree in lieu of academic qualifications.

• A comprehensive and articulate personal statement
• A demonstrable interest in the research area associated with the studentship

Funding and eligibility

The University offers the following levels of support:

Vice Chancellors Research Studentship (VCRS)

The following scholarship options are available to applicants worldwide:

• Full Award: (full-time tuition fees + £19,000 (tbc))
• Part Award: (full-time tuition fees + £9,500)
• Fees Only Award: (full-time tuition fees)

These scholarships will cover full-time PhD tuition fees for three years (subject to satisfactory academic performance) and will provide a £900 per annum research training support grant (RTSG) to help support the PhD researcher.

Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Please note: you will automatically be entered into the competition for the Full Award, unless you state otherwise in your application.

Department for the Economy (DFE)

The scholarship will cover tuition fees at the Home rate and a maintenance allowance of £19,000 (tbc) per annum for three years (subject to satisfactory academic performance).

This scholarship also comes with £900 per annum for three years as a research training support grant (RTSG) allocation to help support the PhD researcher.

• Candidates with pre-settled or settled status under the EU Settlement Scheme, who also satisfy a three year residency requirement in the UK prior to the start of the course for which a Studentship is held MAY receive a Studentship covering fees and maintenance.
• Republic of Ireland (ROI) nationals who satisfy three years’ residency in the UK prior to the start of the course MAY receive a Studentship covering fees and maintenance (ROI nationals don’t need to have pre-settled or settled status under the EU Settlement Scheme to qualify).
• Other non-ROI EU applicants are ‘International’ are not eligible for this source of funding.
• Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Due consideration should be given to financing your studies. Further information on cost of living