Researchers unravel the sexual secret of the health enemy Aspergillus!

Researchers unravel the sexual secret of the health enemy Aspergillus!

On January 12, 2025, researchers at the Friedrich-Alexander University Erlangen-Nuremberg made significant progress in basic research on the mold Aspergillus fumigatus. They identified an important pheromone that plays a central role in the sexual cycle of this opportunistic pathogen. This discovery could not only advance the understanding of sexual reproduction in fungi, but also have important implications for the management of aspergillosis, a potentially fatal infection that particularly affects immunocompromised individuals. Prof. Dr. Sven Krappmann and an international team have successfully identified the gender-specific pheromone, known as a-factor, and determined its function in reproductive processes.

Sexual reproduction in fungi occurs through the release of pheromones that are recognized by special receptors. Until now, it was unclear whether a pheromone like the a-factor existed. The identification of this pheromone closes a significant gap in our knowledge of the sexual reproduction of ascomycetes. These pheromones are actively released in a way that influences the interactions between the fungi and promotes the formation of sexual fruiting bodies, also called cleistothecia. A. fumigatus was recognized as a sexual partner in these processes as early as 2009, but the precise molecular biology behind this process remained poorly understood until now. FAU reports that these new findings are also relevant for future studies on speciation in the fungal kingdom and protection against mismating.

Health risks caused by Aspergillus fumigatus

Aspergillus fumigatus is not only an important part of the environment, but also a serious airborne pathogen. This fungus can lead to serious, invasive infections, particularly for immunocompromised patients, with a shockingly high death rate. According to clinical microbiology reports, this can result in a mortality rate of up to 100% in severely affected patients. Public health research points out that an estimated 16 million cases of lung infections caused by A. fumigatus occur annually, resulting in hundreds of thousands of deaths.

A central problem in the treatment of aspergillosis is the growing resistance to common fungicides, especially triazoles. Specific mutations in the CYP51A gene are the main cause of resistance. The latest research results show that resistant isolates with wild-type CYP51A also occur, which makes diagnosis and therapy more difficult. Given these challenges, new approaches to treat azole-resistant isolates are urgently needed. The scientific community is working hard to develop effective strategies to control the spread of resistance and improve treatment outcomes.

Outlook for future research

The new insights into the pheromone a-factor and the mechanisms of sexual reproduction in A. fumigatus potentially offer groundbreaking approaches for future research. Understanding how this fungus reproduces sexually can be instrumental in better controlling the risk factors that lead to the emergence of new, pathogenic strains. Advances in genetic engineering and new animal models could help to further explore the mechanisms of resistance and immunological responses to A. fumigatus. Continued research in mycology is essential to effectively address the challenges of invasive fungal infections, amplified by the COVID-19 pandemic.