Our team

We are a multidisciplinary team of postdoctoral researchers, PhD and MPhil students, and undergraduate students, and collaborate with many other researchers from elsewhere in the University and the world.

Martin Welch

Research Group Lead
Professor of Microbial Physiology and Metabolism

Function: To keep the money coming in, the papers going out, and to foster a productive and nurturing research and training environment.

Mentorship style: I favour informal but regular meetings. I operate an “open door” policy.

Keywords: Microbial metabolism, quorum sensing, virulence, AMR, biofilms, Pseudomonas aeruginosa, polymicrobial cultures.

Brexit: No thanks.

Isabel Askenasy

Postdoctoral Research Associate

My work aims to better understand the complex wiring and rewiring of quorum sensing in Pseudomonas aeruginosa. Using a novel proteomics approach, I am studying the interactome of autoinducer molecules in quorate cells. I am also investigating bypass mechanisms for quorum-deficient mutants, using an inducible hypermutator developed in the lab.

Outside of work, I like to explore nature and spend time with my cat.

Cemile Selin Aksoy

Postdoctoral Research Associate

I am a bioengineer with a PhD in Molecular Microbiology from the University of Nottingham. My doctoral research focused on identifying novel antibiotic targets by characterising the metabolic functions of the Pseudomonas aeruginosa aminoglycoside resistance gene, aph.
Currently, I am investigating mutations in a P. aeruginosa gene encoding the elongation factor FusA1, which are strongly associated with high-level antibiotic resistance. By uncovering the molecular basis of these mutations and their role in antimicrobial resistance, I aim to contribute to the development of new strategies to combat life-threatening infections caused by this challenging pathogen.

Outside the lab, I enjoy discovering new places, exploring different cuisines, and unwinding in nature, often through hiking, cycling, or tending my small garden.

Sivan Nir

Postdoctoral Research Associate

Joint with the Zhang Lab

I am a postdoctoral researcher in the Zhang lab at the Yusuf Hamied Department of Chemistry, though I consider the Welch lab my second home. I specialise in biointerfaces and functional nanomaterials design with over 10 years of experience in both academia and industry. My current research aims to advance electrochemistry as a tool to study biofilms and control their surface interactions, growth, and pathogenicity. In particular, I focus on developing novel biomimetic electrochemical-responsive materials designed to combat biofouling and address antimicrobial resistance (AMR).

Outside the lab, I enjoy discovering new places with my family, and try to get any bit of sunshine the UK has to offer.

Qingqing Xu

Visiting Research Associate

I am an academic visitor in the Welch lab. My former research mainly focussed on the mechanisms of AMR in Klebsiella pneumoniae. In the Welch lab, I am investigating the function of MexT in aminoglycoside resistance and biofilms in Pseudomonas aeruginosa.

Teca Galvao

Visiting Research Associate

I’m a researcher at Fiocruz (Rio de Janeiro, Brazil) where I’m involved in projects mostly about bacterial antibiotic resistance. These often look at gene regulation or signalling through genetics, biochemistry and a bit of structural (wet or computational) biology. Other collaborations involve Chagas disease and SARS-CoV.

I love taking photos of plants and seeds, and am learning to play volleyball. I have many dreams, silly ones like going to lots of summer music festivals and wilder ones, like more just and peaceful societies.

Pok-Man Ho

PhD Student

My aim is to use ecological approaches to model and better understand microbiology in the context of infection. I have a background in Ecology, Earth Sciences and Computational biology, with degrees from The University of Hong Kong (BSc) and Imperial College London (MRes). Since arriving in Martin's group, I have collaborated enthusiastically with virtually all of the other members of the group, during which time I have developed a model evaluating the influence of medications on microbial interactions (taking cystic fibrosis airway as an example of polymicrobial ecosystems) and a containerized software on calculating selection pressure (dN/dS) for spotting environment-specific signals in the genome.

Outside of my work, I am an avid member of Fitzwilliam College's boat club, and I enjoy playing and composing classical music.

Rahan Nazeer

PhD Student

My work these last few years has revolved around Pseudomonas aeruginosa and the capacity it has to move biological molecules from its interior to its exterior. Along the way, I have become variously obsessed with Type II secretion (the exoproteome), Type III secretion (host intoxication), Type VI secretion (intermicrobial warfare). My PhD project focuses on the biofilm matrix and an unstudied secretion system.

Some of my favourite things to do outside of the lab are to cook for people I love, swim in the river and to read/write/talk about poems.

Jemima Swain

PhD Student

I am interested in the ways in which Pseudomonas aeruginosa and other key cystic fibrosis airway pathogens (Staphylococcus aureus, Stenotrophomonas maltophilia, and Candida albicans) adapt to life in the CF airways. I am currently investigating the patterns of adaptation we see when we grow these species in lung-mimicking media, and when we culture the different species together. My research utilises an in vitro model of the CF airways developed by the Welch Lab, which we can use to stably grow pathogen species alongside each other over long time periods.

When I’m not in the lab, I'm probably ceilidh-ing, sewing/knitting/crocheting, wild swimming, or adding yet another new hobby to this list!

Edoardo Labrini

PhD Student

I am investigating the function of putative small RNAs in Pseudomonas aeruginosa within the polymicrobial environment of cystic fibrosis, which also includes species such as Candida albicans and Staphylococcus aureus. My research aims to understand the regulatory roles of these RNAs in interspecies interactions. I previously gained experience in small RNA characterization during my one-year Master’s thesis internship at the University of Milan, where I contributed to explore the role of small RNAs in biofilm formation and antibiotic resistance. Through my PhD, I seek to uncover novel small RNA-mediated mechanisms that contribute to bacterial adaptation and survival in complex polymicrobial infections.

In my own time, I am a midfield linchpin in Fitzwilliam College's 2nd football team (League Winners, Cuppers Final Losers) and I am Italian.

Isabella Sheldon

PhD Student

Joint with the Godlee Lab

While typically considered to be an extracellular pathogen, P. aeruginosa has been shown to invade and survive within a range of host cells. However, the biology of this intracellular infection remains incompletely understood. My PhD research aims to identify and characterise factors which influence P. aeruginosa survival within the airway epithelial niche.

Amy Askin

PhD Student

I completed my undergraduate degree in Microbiology at Trinity College Dublin, where I developed a strong interest in bacterial pathogenesis, whilst also gaining research experience studying phospholipases thought to be virulence factors in Acinetobacter baumannii. My PhD research will focus on the metabolic regulation of virulence in Pseudomonas aeruginosa, contributing to our team’s wider efforts in understanding Pseudomonas aeruginosa infections.

Felix Kriedemann

PhD Student

I’m originally from Munich, Germany, and recently finished my BSc in Biology with a minor in Chemistry at Springfield College, USA, graduating Magna Cum Laude. During my undergraduate studies, I completed multiple internships in Analytical Characterization at Sandoz and Novartis, where I supported biosimilar development and method optimization using techniques such as HPLC, Capillary Electrophoresis, and Mass Spectrometry. I also conducted research on soil-derived antibiotic-producing bacteria as part of the Tiny Earth initiative and gained additional research experience through independent studies in cell biology and genetics. As a member of the TriBeta National Biology and Chemistry Honors Society, I’ve built a strong academic foundation in the life sciences. I am particularly fascinated by the inter-species interactions between P. aeruginosa and other microbial inhabitants of the CF airway environment.

Rosa Whittingham

MPhil Student

I graduated from the University of York in 2025 with a BSc (Hons) in Biology. My dissertation project focused on determining the function of pseudaminic acid biosynthesis enzymes in pathogenic Clostridia. I also completed a year in industry placement in the Borrill Lab at the John Innes Centre, where I worked on identifying novel genetic variation to increase micronutrient content in wheat. During my studies, I developed a keen interest in antimicrobial resistance which I am now exploring further through an MPhil in the Welch Lab, investigating the impact of multidrug resistance on the fitness and virulence of Pseudomonas aeruginosa. I am particularly interested in the evolutionary trade-offs associated with resistance and their implications for infection control and treatment strategies.