Novel Treatment Approach for Aspergilloses by Targeting Germination

Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.