Dr Giusy Mariano
- Research Fellow (Immunology & Infection)
Biography
Much of my scientific career has been focused on investigating bacterial warfare.
My PhD and first Postdoctoral position, at the University of Dundee, were focused on the investigation of the molecular basis of the anti-bacterial activity of the Type VI Secretion System in Serratia marcescens.
After this, I completed a short postdoc in the lab of Dr Julien Bergeron, investigating the mechanism underpinning the assembly of the bacterial flagellum in Salmonella spp.
In 2020, I was awarded a Sir Henry Wellcome Fellowship, which allowed me to start my own line of research focused on the discovery and characterisation of novel anti-phage systems. This fellowship took place between Newcastle University, where I conducted the initial phase of my work, and the University of Surrey, where I completed the project in 2024.
During this time, my research contributions have led to several publications reporting the discovery of previously unidentified anti-phage systems with unique mechanism of actions in Pseudomonas and Serratia species.
My current research as Lecturer (and starting March 2025 as MRC Career Development fellow) at the School of Infection & Immunity will delve into understanding the fundamental mechanisms underpinning the evolutionary dynamics between bacteria and their anti-phage systems and phages.
Using physiologically-relevant models, I will also explore how these dynamics can potentially impact the rapidly evolving field of phage therapy.
Research interests
Bacteriophages (phages) outnumber bacteria in the environment, creating selective pressure that has driven bacteria to develop a wide array of anti-viral strategies, while phages, in turn, evolve counter-measures.
In recent years, approximately 200 new anti-phage systems have been discovered in bacterial genomes. Understanding this evolutionary arms race is uncovering exciting new areas of biology, including unexpected links between phage defence mechanisms and the innate immune systems of animals and plants.
My research combines comparative genomics, genetics, biochemistry, single-cell microscopy, and structural biology to identify novel loci involved in phage defence and elucidate the mechanistic details of these defence pathways.
This includes investigating how interactions with phages trigger these systems and the downstream responses that confer immunity. I am particularly focused on anti-phage systems in Serratia marcescens (and other species), Escherichia coli, and Pseudomonas aeruginosa.
A key aspect of our work is to build more physiologically relevant contexts to better understand the role of these systems in vivo, incorporating appropriate environmental cues during phage predation, as well as their evolutionary dynamics with phages. This research has the potential to significantly impact the rapidly developing field of phage therapy.
Publications
Prior publications
Article
Williams DJ et al. (2025) Competitive behaviors in Serratia marcescens are coordinately regulated by a lifestyle switch frequently inactivated in the clinical environment. Giuseppina Mariano . (doi: 10.1016/j.chom.2025.01.001)
Macdonald Elliot, Rosanna Wright, James Connolly, Strahl Henrik, Brockhurst Michael, Stineke van Houte, Blower Tim R., Palmer Tracy, Mariano Giuseppina (2023) The novel anti-phage system Shield co-opts an RmuC domain to mediate phage defense across Pseudomonas species University of Surrey - Research Repository. ISSN 1553-7390 (doi: 10.1371/journal.pgen.1010784)
Mariano Giuseppina, Blower Tim R. (2023) Conserved domains can be found across distinct phage defence systems University of Surrey - Research Repository. ISSN 0950-382X (doi: 10.1111/mmi.15047)
Garrett Stephen R., Mariano Giuseppina, Dicks Jo, Palmer Tracy (2022) Homologous recombination between tandem paralogues drives evolution of a subset of type VII secretion system immunity genes in firmicute bacteria University of Surrey - Research Repository. ISSN 2057-5858 (doi: 10.1099/mgen.0.000868)
Giuseppina Mariano (2022) Bacterial pore-forming toxins. Giuseppina Mariano . (doi: 10.1099/mic.0.001154)
Giuseppina Mariano (2022) Homologous recombination between tandem paralogues drives evolution of a subset of Type VII secretion system immunity genes in firmicute bacteria Giuseppina Mariano . (doi: 10.1101/2022.01.07.475358)
Garrett Stephen R., Mariano Giuseppina, Palmer Tracy (2022) Genomic analysis of the progenitor strains of Staphylococcus aureus RN6390 University of Surrey - Research Repository. ISSN 2516-8290 (doi: 10.1099/acmi.0.000464.v3)
Giuseppina Mariano (2021) Oligomerization of the FliF Domains Suggests a Coordinated Assembly of the Bacterial Flagellum MS Ring. Giuseppina Mariano . (doi: 10.3389/fmicb.2021.781960)
(2020) Structural Characterization of SARS-CoV-2: Where We Are, and Where We Need to Be. Giuseppina Mariano . (doi: 10.3389/fmolb.2020.605236)
(2019) A family of Type VI secretion system effector proteins that form ion-selective pores Giuseppina Mariano . ISSN 2041-1723 (doi: 10.1038/s41467-019-13439-0)
Adam Ostrowski, Francesca R. Cianfanelli, Michael Porter, Giuseppina Mariano, Julien Peltier, Jun Jie Wong, Jason R. Swedlow, Matthias Trost, Sarah J. Coulthurst, Melanie Blokesch (2018) Killing with proficiency: Integrated post-translational regulation of an offensive Type VI secretion system Crossref Metadata Search. ISSN 1553-7374 (doi: 10.1371/journal.ppat.1007230)
Giuseppina Mariano, Laura Monlezun, Sarah J. Coulthurst (2018) Dual Role for DsbA in Attacking and Targeted Bacterial Cells during Type VI Secretion System-Mediated Competition Crossref Metadata Search. ISSN 2211-1247 (doi: 10.1016/j.celrep.2017.12.075)
Grants
Grants and Awards listed are those received whilst working with the University of Glasgow.
- Phage Journeys: Unraveling Prophage and Antiphage systems Mobilisation in P. aeruginosa for Enhanced Phage Therapy Efficacy
Medical Research Council
2025 - 2030