Southampton University Enlists Citizen Scientists to Isolate Phages for Antimicrobial Resistance Research

Researchers at the University of Southampton are actively engaging the public in a citizen science initiative to identify bacteriophages as potential therapeutic agents against antimicrobial resistance (AMR), a project presented at the Royal Society Summer Science Exhibition. The methodology involves the collection and submission of diverse environmental water samples – sourced from domestic, park, river, and even toilet environments – for subsequent phage isolation and characterisation. This approach seeks to leverage the particular lytic activity of phages – viruses that replicate at the site of bacterial infection – to target harmful bacteria while preserving commensal microbial communities, offering a potentially sustainable alternative to broad-spectrum antibiotics. The urgency of this research is underscored by the World Health Organisation’s assessment of AMR as a critical global health threat, estimated to be directly responsible for over one million deaths and contributing to over 4.7 million deaths annually as of 2021, and jeopardising the efficacy of numerous medical procedures reliant on effective antibiotic prophylaxis.

Citizen Science and the Search for Phages

Citizen science is playing an increasingly vital role in addressing the global crisis of antibiotic resistance, as exemplified by a novel project spearheaded by researchers at the University of Southampton. Unveiled at the Royal Society Summer Science Exhibition, opening on 1 July in London, the initiative actively enlists public participation in the search for bacteriophages – viruses that specifically infect and kill bacteria. Participants are invited to collect and submit water samples from a diverse range of environments, including domestic sources, public parks, rivers, and even treated effluent, providing a geographically broad and ecologically representative collection pool. This crowdsourced approach significantly expands the scope of phage discovery beyond the limitations of traditional laboratory-based research.

The underlying principle rests on the inherent abundance and diversity of phages in natural environments. Bacteriophages, distinct from broad-spectrum antibiotics, exhibit a particular host range, targeting only particular bacterial strains. This precision minimises disruption to the commensal microbiome – the community of beneficial microorganisms residing within a host – a significant drawback of conventional antibiotic treatments. The research team, led by experts at the University of Southampton, aims to isolate and characterise phages capable of infecting antibiotic-resistant bacteria, with a particular focus on identifying those exhibiting lytic activity – the ability to induce bacterial cell lysis, or rupture. Following sample submission, the collected water will undergo rigorous laboratory analysis, including enrichment cultures designed to amplify phage populations selectively. Characterisation will involve electron microscopy for morphological assessment, genomic sequencing to determine the phage’s genetic makeup, and in vitro assays to evaluate its efficacy against clinically relevant antibiotic-resistant strains.

The potential of this research lies in the development of phage therapy – the therapeutic use of bacteriophages to treat bacterial infections. The World Health Organisation recognises antimicrobial resistance (AMR) as a critical global health threat, reporting over one million deaths directly attributable to AMR and a further 4.7 million deaths with AMR as a contributing factor as of 2021. The specificity of phages, coupled with their ability to replicate at the site of infection, offers a potentially sustainable and efficient alternative to antibiotics. Unlike antibiotics, which often exert selective pressure leading to the rapid evolution of resistance, phages can co-evolve with their bacterial hosts, maintaining their efficacy over time. This project, therefore, represents a crucial step towards harnessing the power of phages to combat the escalating threat of antibiotic resistance and safeguard public health, particularly in the context of increasingly complex medical procedures where effective antibiotics are paramount.

The Escalating Crisis of Antimicrobial Resistance

The escalating crisis of antimicrobial resistance (AMR) demands innovative therapeutic strategies, and a collaborative project spearheaded by researchers at the University of Southampton is actively investigating phage therapy as a potential solution. Presented at the Royal Society Summer Science Exhibition, opening July 1st in London, the initiative uniquely enlists public participation as ‘citizen scientists’ in the search for bacteriophages – viruses that specifically infect and kill bacteria. This approach acknowledges the scale of the problem; the World Health Organization estimates that AMR was directly responsible for over one million deaths and contributed to a further 4.7 million deaths globally in 2021, highlighting the urgent need for novel interventions.

The core of the research focuses on isolating phages from diverse environmental reservoirs, including readily accessible sources like domestic water, parks, rivers, and even sewage. This broad sampling strategy is predicated on the understanding that phages are ubiquitous in the environment and represent the most abundant biological entities on Earth. Following sample collection and submission, rigorous laboratory analysis is undertaken, beginning with enrichment cultures. These cultures are designed to selectively amplify phage populations by providing a suitable environment for phage replication while suppressing bacterial growth. Characterisation of isolated phages involves a multi-faceted approach. Electron microscopy is employed to visualise phage morphology – their size, shape, and structural components – providing initial clues about their taxonomic affiliation. Crucially, genomic sequencing is performed to determine the complete nucleotide sequence of the phage genome, revealing its genetic makeup and potential virulence factors. In vitro assays are then conducted to evaluate the efficacy of the isolated phages against clinically relevant, antibiotic-resistant strains of bacteria. These assays measure the phage’s ability to lyse – rupture – bacterial cells, a key indicator of its therapeutic potential.

The specificity of phage-mediated bacterial killing represents a significant advantage over broad-spectrum antibiotics. Antibiotics often disrupt the commensal microbiota – the beneficial bacteria residing in the human gut and on the skin – leading to secondary infections and compromising immune function. Phages, however, typically exhibit a narrow host range, targeting only specific bacterial species or strains, thereby minimising disruption to the beneficial microbiome. Furthermore, bacteria can develop resistance to antibiotics through various mechanisms, including enzymatic degradation, target modification, and efflux pump overexpression. While phage resistance can also emerge, phages possess the capacity to co-evolve with their bacterial hosts, adapting to overcome resistance mechanisms and maintain their efficacy over time. This dynamic interplay between phage and bacteria offers a potentially sustainable therapeutic strategy, mitigating the risk of widespread resistance development. The project, therefore, represents a crucial step towards harnessing the power of phage therapy to combat the escalating threat of antibiotic resistance and safeguard public health, particularly in the context of increasingly complex medical procedures where effective antibiotics are paramount.

Phage Therapy: A Targeted Approach

Phage therapy, an increasingly investigated approach to combating antimicrobial resistance (AMR), is at the forefront of research conducted by scientists at the University of Southampton. This project, unveiled at the Royal Society Summer Science Exhibition, actively enlists public participation as ‘citizen scientists’ in the search for bacteriophages – viruses capable of infecting and lysing bacteria. The methodology centres on the collection of environmental water samples from diverse sources – encompassing domestic environments, public parks, rivers, and even sewage – to maximise the probability of isolating novel phages with therapeutic potential.

The rationale underpinning phage therapy lies in its inherent specificity. Unlike broad-spectrum antibiotics, which indiscriminately target both pathogenic and commensal bacteria, phages exhibit a narrow host range, typically infecting only specific bacterial species or strains. This precision minimises collateral damage to the beneficial microbiome, a critical component of human health and immune function. The World Health Organisation identifies AMR as a global health crisis, estimating over one million deaths directly attributable to antibiotic resistance and contributing to over 4.7 million deaths annually as of 2021. The escalating threat of AMR not only complicates the treatment of common infections, leading to prolonged morbidity and increased healthcare costs, but also jeopardises the safety of essential medical procedures – including chemotherapy, organ transplantation, and even routine dental work – where post-operative infections, if untreatable, can prove fatal.
Initial phage isolation involves enrichment cultures, where environmental samples are incubated with target bacterial strains to amplify phage populations selectively.

Following isolation, rigorous characterisation is undertaken, including morphological analysis via transmission electron microscopy to determine phage structure and size. Genomic sequencing is then performed to elucidate the complete nucleotide sequence of the phage genome, revealing its genetic makeup and potential virulence factors. In vitro assays are subsequently conducted to evaluate the efficacy of the isolated phages against clinically relevant, antibiotic-resistant strains of bacteria. These assays measure the phage’s ability to lyse – rupture – bacterial cells, a key indicator of its therapeutic potential. Crucially, the project acknowledges that while bacteria can develop resistance to phages, phages possess the capacity to co-evolve with their bacterial hosts, adapting to overcome resistance mechanisms and maintain their efficacy over time. This dynamic interplay offers a potentially sustainable therapeutic strategy, mitigating the risk of widespread resistance development. The University of Southampton’s initiative, therefore, represents a crucial step towards harnessing the power of phage therapy to combat the escalating threat of antibiotic resistance and safeguard public health, particularly in the context of increasingly complex medical procedures where effective antibiotics are paramount.