Face masks: always a healthy choice during this COVID-19 pandemic?

Due to the corona pandemic, Belgium went into lockdown starting from the 18th of March 2020. Multiple changes in our day-to-day life had to be made as more and more regulations came into place. Physical distancing and wearing face masks are the ‘new normal’ in our country at the moment. Moreover, face masks are increasingly obliged in the community, outside hospitals and care facilities, mainly based on the precautionary principle, since conclusive evidence is not (yet) available. Face masks are a medical device and placebo-controlled conclusive well-controlled clinical trials that prove the benefit of wearing a face mask in community settings are lacking (Martin, 2020). Such studies are important to double check safety and efficacy of medical devices and drugs. While well-designed face masks show high efficacy in specific settings, such as in hospitals with a high chance of COVID-19 patients, they could also have some unexpected side effects. Due to a shortage of the surgical face masks at the beginning of the crisis, self-made cotton face masks are promoted, but their safety and efficacy is not well documented. Wearing them for longer periods of time, like in schools and restaurants, could result in a concentration of microbes on the masks that should be carefully monitored.

What we as bioscience engineers learn in our first microbiology lesson is that bacteria and fungi need a surface or substrate, moisture, a little bit of food, nice temperature, and an absent immune system to grow exponentially. This environment seems to be exactly what is created when wearing a face masks for multiple hours. When these masks are then not washed or disinfected properly, these bacteria might resume on the face mask even before using it.

For a scientist, “measuring is knowing” is the most important life motto and so we started experiments in the lab to determine how many bacteria could concentrate on different mask types after wearing them for four hours and how to clean them in the best way. In the figure below you can see the set-up of our experiments.

First of all, we could see that cotton masks concentrate 10 to 20 times more bacteria than the surgical-type masks tested. This might be due to the higher amount of moisture in the cotton masks and less antimicrobial and more growth supporting properties of the material used. Surgical face masks always contain a filter and consist of more absorbing material.

Furthermore, we isolated bacteria from the mouth masks and tested their resistance to the antibiotics erythromycin and ampicillin. In the figure below, you can see that almost 50% of the isolates tested were resistant to at least one antibiotic and some isolates were even resistant to both antibiotics. It has been stated by the WHO that by 2050 more people will die from an infection caused by antibiotic resistant bacteria than cancer (WHO, 2019). An important concern is that the increased use of face masks in the community should not negatively contribute to this trend. Antibiotic stewardship is still crucial, also during the COVID-19 crisis (Hsu, 2020).

Lastly, we tested different washing and disinfection methods for the self-made cotton masks, to determine the best way to get rid of these bacterial cells on the masks. We tested: washing at 100°C, washing at 60°C with soap, ironing with a steam iron, putting it in the freezer overnight and leaving it on a counter top for 72h. As can be seen in the figure below, we can recommend to either wash your mask at 100°C or 60°C with soap or use a steam iron. These methods resulted in 25 times, 60 times, and 95 times less bacteria, respectively.

Based on these results, we are no advocates for the obligation of face masks in the community at places where physical distancing is possible. A high number of bacteria is present on these masks, especially on the cotton masks, and not handling or washing them properly might be harmful. By touching the mask, bacteria and viruses present on the face mask could spread easily, especially when the masks have become humid, because liquid is known to promote microbial transfer. In addition, people that wear a face mask often touch their face more frequently, increasing the chances to spread unwanted microbes. The good news is, that the bacteria we could identify on the masks are unlikely to make you instantly sick. However, they could cause acne and other skin infections, especially in combination with the friction of the face mask on the skin. Furthermore, food infections might occur due to touching the mask with your hands. In the worst-case scenarios, lung and systemic infections can be caused since bacteria could grow exponentially out of the control of our immune system and microbiota. Especially when bacteria show antibiotic resistance, safety measures must be taken when using these masks.

As bacteriologists, we recommend to ensure social distancing and wash your hands as much as needed. These actions are very effective and should always be taken as first safety measures in the community during a pandemic. When physical distancing is not possible for longer than a few minutes (15 minutes is often used as a general rule to determine high-risk contacts) and when the SARS-CoV-2 infection rate in the community is still high, face masks are advised. But they must be used properly and stored in a breathable container to transport home or when not used for a certain period (anyway, wearing masks longer than 4 hours seems not advisable based on our results☺). If available, surgical-like masks are preferred, as they hold less bacteria, and can be easily disposed of after wearing.

Starting a PhD during lockdown

When you start a new job, you always have the first-day or even first-week jitters. For me, this was not any different. My first workweek was quite unusual as it coincided with the lab retreat. This week was full of meetings, workshops and the ongoing and upcoming research projects were discussed. This retreat was a great opportunity to get to know my colleagues and their research topics. If you are interested be sure to read our blogpost about the lab retreat. 

After this interesting and fun week, I was looking forward to my first ‘normal’ week on the job. Unfortunately, this was not a standard week either. It was cut short as SARS-CoV2 started taking over Belgium. Due to the corona crisis, telework became the norm. After cleaning out a messy room at home, I created a private office where I could work undisturbed. As for everyone, adapting was not always so easy, but it was the perfect opportunity to read literature, write a review and freshen up my bioinformatic skills. I learned the basics of the R programming language, improved my Linux skills, and made my first python scripts. Additionally, I investigated what bioinformatic tools could replace our current tools to identify and elucidate novel nonribosomal peptide synthetase clusters. These new skills and tools will be very useful during my PhD. 

As the regular contact with colleagues has diminished, our lab has organized weekly meetings in smaller groups per research topic. The PostDocs take lead of one the groups. During these weekly meetings, we discuss what we are working on, and what we hope to finish by the next meeting. It is not only a great way of motivating yourself and keeping track of your own work progress, but it also helps to combat the loneliness and lack of social contact that comes with telework. Currently, the corona lockdown measures are gradually being relaxed. Hopefully, we can all start working in the lab again soon! 

WANTED: 200 vagina’s to write history #LetsSwab

Today, after a year of hard preparational work, we are launching our Isala project!! Yes, in the midst of the corona-storm, because legendary projects require epic times and also because good timing is overrated.  

So let me tell you about Isala and how you can really make a difference for your own health and that of thousands other women and girls of today and the future. Isala is a brand new large-scale citizen science project led by the lab of Prof. Sarah Lebeer at the University of Antwerp. Isala is named after Isala Van Diest (1842-1916), the very first female medical doctor in Belgium. She had to study in Germany because no women were admitted to Belgian universities at the time. But she persisted. And she made history. Because thanks to her, a Royal Decree appeared in 1884 that allowed women in Belgium to become medical doctors. So we named our citizen science project after this strong lady, because we are also looking for women who want to write history. Women like you?!

How can you help us? Well, there are millions of micro-organisms in your vagina that play a crucial role in your health. They are extremely important to protect you against vaginal infections, bladder infections, STIs, etc. and we suspect that they also play a major role in fertility and healthy pregnancies. Only… we are not sure. Until recently, scientific research unfortunately has not had a lot of interest in the vaginal microbiome. Isala wants to change this. With your help, we want to try for the very first time to better understand the female microbiome in Flanders with state of the art DNA technology.

“This groundbreaking research could eventually lead to new, unseen possibilities for both diagnostics and therapies.”

Prof. Sarah Lebeer

Isala is more than just an epic self-sampling citizen science project. With Isala we want to empower women to take their own vaginal samples, make them more aware of their own health and recognize alarm signals. We also want to break taboo and open the floor to facilitate communication about vaginal health.

Women in Flanders who want to participate can easily register via www.isala.be. If you do not live in Flanders or cannot participate but believe everyone should know about Isala, feel free to share our message with the world.

Let’s swab for the future. #LetsSwab

Lab Retreat 2020

Lize Delanghe & Eline Cauwenberghs

During the last few months, a lot has changed in our lab. Some of our beloved postdocs decided to change university scene and a lot of new PhD students started. Additionally, our PI, Sarah Lebeer, received an ERC Starting grant (yeey!). Therefore, we decided that it was time to sit together with a new group and recap previous research projects and brainstorm about new ones. After making a planning and buying food for the whole week, we left for Kalmthout to start our labretreat!

After unpacking and installing at what would be our new home for one week, we started our labretreat with a brainstorm for the very next paper we would like to write. Tuesday was our first full day in the house and so the official introduction of our lab retreat. Sarah made an introduction presentation with a timeline of the lab (including some amazing pictures of the first lab equipment) and an overview of the ERC project. In the afternoon, we discussed novel technologies that are not yet used in our lab but could be interesting for some projects, including FACS, FPLC, knock-out mutants, … After the technology meeting, every PhD student prepared some slides for their short-term goals to update the whole lab. This way, other lab members could give input and offer help for future projects. On Wednesday we talked about lab optimization. Running a lab smoothly is not an easy task, but it definitely goes better if everyone does their share of the work. We have much to thank to our lab technicians for this daily smooth operation. Finally, the last day was filled with bigger project brainstorms.

Next to all our very inspiring and successful meetings, we enjoyed a lot of different social activities. For diner, we found some volunteers coming up with delicious recipes to make a varied and healthy menu for the whole week. Cooking together turned out to be one of the best team building activities! All tasks were divided spontaneously: from chef to sous chef, serving drinks and snacks to even checking safety (cfr. managing to take hot quiches in silicone baking molds out of the oven). After diner, thanks to the two dishwashers in the house, we still had time to play pool, table football and a lot of board games, such as the hilarious and absurd game ‘Shit happens’. One night, we even built our own cinema in the living room, including self-made popcorn! On Wednesday afternoon, we went out for a ‘real’ teambuilding. First, we managed to escape out of four very difficult and exciting rooms. Good proof that our brains were still working very well after all the brainstorm sessions (or some of us are quite goodat cheating 😉). After solving all the puzzles and escaping, it was time to give our brian some rest. We went to a cozy tearoom to have some sweets and ended our day with a sporty walk at the ‘Kalmthoutse Heide’.

NSABS 2020

Every year, the universities of Belgium pull together to organize a general symposium on applied bio(techno)logy. This year, it was the 25th edition of the National Symposium for Applied Biological Sciences, held at the beautiful campus Gembloux Agro-Bio Tech of the University of Liège. 


The University of Antwerp was again well represented, with 11 researchers, of which 8 LebeerLab-members, mostly junior researchers and starting PhD students. Postdoctoral researchers Dieter Vandenheuvel and Irina Spacova were part of the Organizing Committee of this edition. Our PhD students presented their research to the broader public with a nice poster, and gained quite some interest from their peers, other researchers and company representatives present. Two of our students, Eline Cauwenberghs and Sarah Ahannach, were even selected to present their poster with a flash talk of one minute during the “Food technology, safety & health” and “biotechnology” plenary meetings. Eline’s research will further study the potential of our nasopharyngeal isolates as probiotic for the upper respiratory tract. This research was started at the lab 5 years ago, with the isolation of one of our most potent strains, and is now evolving to safety studies in humans. Sarah showed that during the first trimester of pregnancy, the vaginal microbiome of women in Flanders can be differentiated into 5 different profiles.  

The present public could vote for the best poster. We are proud to announce that our PhD student Tom Eilers won the best poster award. His poster shows the practical flow-through of the discovery of a novel and unexpected cellulase in some strains of Lactobacillus mudanjiangensis, starting from the discovery via bio-informatics to the experimental proof. Apart from the nice present Tom has won, it is also a great recognition of the public’s interest in the research on the genetic annotation of novel characteristics we’ve identified in our beneficial lactobacilli.


The conference was concluded with some refreshments and locally brewed beer, and a possibility to network and catch up with our colleagues at the other universities. Proud of our poster winners, and thankful to everyone who voted, we returned homewards. We could all conclude that the organization succeeded again in making a successful edition of NSABS! We are looking forward to next year!