Microbiology Editor’s Choice: an insect model for fungal and bacterial coinfections

Posted on May 7, 2020   by Microbiology Society

Each month, a manuscript published in our flagship journal Microbiology  is chosen by a member of the Editorial Board. This month, the paper is titled “Candida albicans increases the pathogenicity of Staphylococcus aureus during polymicrobial infection of Galleria mellonella larvae” and it was chosen by Dr Hana Sychrová.

Infectious diseases remain aprevalent health threat, with the major causes of mortality due to existing and emerging fungal, parasitic, bacterial and viral pathogens. In order to meet the growing challenges of combating microbial infections, many efforts are being made to understand host-microbe interactions, the rapid increase in antimicrobial resistance of bacteria and fungi and to identify new potential drug targets. Staphylococcus aureus and Candida albicans are among the opportunistic pathogens that serve as model organisms in many studies. Recent findings show that the fungal pathogens and bacteria may co-operate in the host, and their mixed biofilms have new properties – usually showing a greater resistance to antibiotics and antifungals – as well as influencing the host immune system.
To study the collective impact of pathogenic bacteria and yeast, different host organisms are used. In this study, Galleria mellonella larvae present a very good model, which serves to answer various research questions related to the joint action of bacteria and yeast.

Candida albicans increases the pathogenicity of Staphylococcus aureus during polymicrobial infection of Galleria mellonella larvae

The immune system of insects shares many similarities with the innate immune response of mammals. As a result of this, insects can be used to study the ability of fungi and bacteria to cause disease and results show a strong correlation to those from mammalian studies. In this paper larvae of Galleria mellonella were infected with the bacterium Staphylococcus aureus, and the yeast Candida albicans. The results showed that fungal infection increases the ability of the bacterium to grow and infect the insect. These results help to explain why co-infection in humans is often more dangerous tha mono-infection with either a bacterial or fungal pathogen.

We spoke with corresponding author, Professor Kevin Kavanagh to find out more:

What is your institution and how long have you been there?

I am Professor of Microbiology at Maynooth University and I was appointed in 1995. Maynooth University is located 25km west of Dublin city, and has a student population of approximately 14,000.

What is your research area? 

I am interested in fungal pathogens and how they interact with the host immune response. We developed the Galleria infection model to facilitate the study of bacterial and fungal pathogens, and their interactions with the host immune response.

What inspired you to research this topic?

We developed the Galleria infection model to allow researchers to conduct experiments without the need to use mammals. The Galleria infection model is easy to use, cost effective and free of legal and ethical restrictions. Results show a strong correlation to those from mammalian studies and allow researchers to fine-tune subsequent experiments in mammals if necessary.

What is the most rewarding part of your research?

I think the most rewarding part of my research is the ability to work with young, enthusiastic scientists to develop new knowledge of use to other researchers.

What would you be doing if you weren't a scientist?

As a child, my ambition was to be an astronaut!

Check out this blog by co-author Gerard Sheehan for a deeper look at the research project.

Visit our journals platform to access the full paper. Editor’s Choice articles published in Microbiology are free to read.