Johannes Cairns

DDLS Fellow | Microbial Evolutionary Genetics

Johannes Cairns is a DDLS Fellow and Assistant Professor (biträdande lektor) in the Department of Experimental Medical Science at Lund University. He obtained his PhD in microbiology from the University of Helsinki in 2018, followed by postdoctoral research combining experimental evolution, microbial ecology, and computational biology, including a visiting scholar period at the Wellcome Sanger Institute in the UK.

In 2023, Johannes became docent in evolutionary genetics and bioinformatics at the University of Turku. Prior to his move to Lund, he established his independent research profile in Finland as a group leader affiliated with the Turku Collegium for Science, Medicine and Technology and the Finnish Multidisciplinary Center for Antimicrobial Resistance Research (FIMAR), where his work focused on eco-evolutionary dynamics of antibiotic resistance in microbial communities. Johannes continues to lead a group in Turku while establishing a new group in Lund.

Our research

The MEG Lab studies how microbial populations and communities evolve under selective pressures relevant to human health, with a particular focus on antibiotic resistance and community resilience. A central aim is to understand when resistance evolution and treatment outcomes are predictable, and when they depend on ecological interactions between coexisting microbes.

The group integrates experimental evolution, synthetic and clinically inspired microbial communities, genetic engineering, and bioinformatics. While earlier work focused on general principles using controlled community systems, the lab is increasingly developing more clinically grounded models of polymicrobial infection, including biofilm-associated and device-related infections.

Aim

By combining ecological realism with experimental control and quantitative analysis, we aim to generate predictive understanding of resistance evolution and community resilience that can ultimately inform antibiotic use and infection management.

Strengths of the group

A key strength of the MEG Lab is the tight integration of wet-lab experimentation with computational analysis. We draw on highly interdisciplinary expertise spanning microbiology, molecular biology, evolutionary biology, ecology, biomedicine, and computational biology.

The group benefits from strong collaborative links within infection research environments and domain experts in both Sweden and Finland.

Impact

Antimicrobial resistance is one of the most serious challenges facing modern medicine, yet resistance evolution is still often studied in oversimplified systems. By developing experimentally controlled but increasingly clinically realistic models of polymicrobial infection, our research aims to improve understanding of treatment failure, resistance emergence, and long-term infection persistence.

By integrating evolutionary biology and ecology with data-driven life science and medical relevance, our work contributes to the development of evolution- and ecology-aware approaches to antimicrobial therapy.