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MIMS Spotlight Series Extra: Meet Karsten Meier

In the frame of MIMS highlights World Antimicrobial Awareness Week 2021


Text written by Nóra Lehotai and Karsten Meier.

Sixt lab 0163 210120 MPN croppedThis extra episode of the MIMS Spotlight Series is part of "MIMS highlights World Antimicrobial Awareness Week 2021" article series. Karsten joined MIMS in November 2018 to start his PhD studies here. He has German nationality and has been living in Germany, Switzerland and Sweden. His three brothers and parents are constantly cheering for him during running competitions and when he is not in the lab or out running, you can trust him with your pets, he will take good care of them.

 Picture: Karsten Meier explaining his scientific poster. Credit: Mattias Petterson. 


Can you tell us about your role at MIMS, what are you working on now? 

I am a PhD student in Barabara Sixt’s group, about halfway now with my PhD. The group does research on Chlamydia trachomatis. This species of Chlamydia infects only humans, causing blindness and sexually transmitted diseases (STDs), but we are working with a serotype which causes STD and not blindness. I am working on two projects: one is on the virulence factor that Barbara discovered. This factor leads to premature host cell death, which is bad for Chlamydia because it is obligate intracellular, meaning that if the cell dies too early, Chlamydia cannot replicate anymore within the cell, and it also induces a general, defence response in the host cell. Since this virulence factor has been relatively recently described, we are trying to reveal the mechanisms of this factor, what does it interact with and how does it actually manipulate the host cell to avoid the cellular response. We hope to soon submit a manuscript about this.

The second project is focusing on finding new virulence factors. We created a mutant Chlamydia library with random mutations in it and I will infect host cells with it and monitor their growth. If one mutant grows better or worse, that means that the mutation must be in a virulence factor. We use mostly HeLa cell culture to grow Chlamydia.


What were you doing before you joined MIMS and what attracted you to start a position here? 

Karsten studied biochemistry in Hannover, Germany, and parallel running a lot as well.

After finishing my studies, I took a year off to focus on my running career, to run a marathon, for example, but kept working in science related positions for 10 hours per week; in labs and in administration too. I came to Sweden as an exchange student and spent 3 months in Uppsala, which I really enjoyed. It was a beautiful summer! When it came to applying for PhD positions, I knew that I wanted to leave Germany and I liked Sweden. I also didn’t want to move to a big city. I started to apply to different positions, and I remember when seeing Barbara’s position, I thought that it is a good fit because my master thesis was on host-pathogen interactions. First, I thought that Umeå is maybe too far north but now I really like being here.


If you would not have your current profession, what do you think you would be doing? 

The obvious answer would be something sports related. Still would be a professional runner or would have become a personal trainer.

 Karsten 2 cropped

Picture: On the left - Karsten doing a running tour through the deep snow along Isälvsleden. On the right - One of Karsten's favourite spots in the Umeå area: the top of Vallberget at Tavelsjö. Credits: Karsten Meier and Rikki Frederiksen.


What do you do in your free time and what are you most enjoying in living in Umeå, Sweden? 

I run, bike (race bike, mountain bike), ski, swim, skate, rollerblade. Umeå and its surroundings are really a good place for outdoor activities, many sport clubs and associations are present.

I enjoy the diversity of the seasons and what they enable: in summer, you can bath in lakes and rivers but in winter you have snow, and you can skate on lakes. There are not so many places on Earth where you have these options. Plus, of course seeing the aurora, is very exciting.


Is there a little known/interesting fact about yourself? 

When I was young, I was doing all kinds of athletic sports, but it turned out that I was only good at running, says Karsten. By the age of 6, I started to focus on running only and at 8-10 years old, I was participating at 5 km races already. At some professional competitions, where the nationality matters, I run under the German flag because unfortunately, double nationalities are not allowed in Sweden when it comes to sports, but otherwise I am member of the IFK Umeå sport club.


Antimicrobial Awareness

To Karsten, it means:

GoBlue Concept asset“Not to take for granted that we can treat infections and to value antimicrobials. Antimicrobial drugs are saving lives every day and to be aware of this, means to take careful care of this treasure.”



Chlamydia infections are treated with broad-spectrum antibiotics

“I do research on Chlamydia trachomatis, a bacterium that is in most cases effectively treatable with broad spectrum antibiotics. But even though we have very good antibiotics against Chlamydia trachomatis, we search for new ways to treat it, because we have to reduce the use of antibiotics to slow down development of resistance as much as possible.”

Karsten specifically works on one of the virulence factors, a protein which Chlamydia trachomatis uses to manipulate the host cell in a way that it cannot induce its defense machinery anymore.

“If we could unleash the powerful, but by Chlamydia trachomatis disabled, defense machinery of the host cell, it could get rid of the infection on its own, or treat chlamydial infections with more specific drugs without the usage of broad-spectrum antibiotics.”


Local vs global use of antibiotics: places for improvements

In Sweden, use of antibiotics is comparably responsible. The use of antibiotics is relatively low and as a reward, there are fewer resistant bugs than in many other countries. But if I think globally, continues Karsten, I think the use of antibiotics must be described as irresponsible and lavish. Antibiotics are not valued as lifesaver, but just seen as a way to make short term gains, for example to increase yields in the meat production. The consequence is that people die in hospitals from multi-resistant bugs that we cannot treat anymore. Untreatable bugs are not just a theoretical threat in the future, but a reality that the health care system faces every day.

I think what has to change in the society is that we all need more respect and appreciation of this fantastic weapon that we still have, but that is turning less and less effective the more we use it. We must understand the value and fragility of antibiotics and as a society, make sure that there is enough pressure on policymakers so that they introduce rules that extend the life-length of antibiotics.


World Antimicrobial Awareness Week 2021 illustration "Go Blue" by WHO.

Emmanuelle Charpentier took the Nobel Prize in Chemistry

Emmanuelle has been awarded jointly with Jennifer Doudna the 2020 Nobel Prize in Chemistry for discovering the groundbreaking CRISPR-Cas9 gene editing technology. She is a former group leader at MIMS, honorary doctor at Umeå University and former visiting professor at UCMR.

Movie by Knut and Alice Wallenberg Foundation (

Battling antibiotic resistance

movie by Knut and Alice Wallenberg Foundation, with participation of scientists from MIMS and UCMR:
Or watch the original movie on:

Research about infectious diseases:

Oliver Billker in movie of Knut and Alice Wallenberg Foundation:
Or watch the original movie on:

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