It was expected that the results obtained in this way might improve our understanding of the pathogenesis of fungal infection, especially the transition from colonization to invasion, and the problems associated with bacterial co-infections. A. Gentiopicrin fumigatus was selected as the object of study because of its potential to provide clinically relevant information as well as new insights into the effects of PAMPs on fungal metabolism. The addition of PAMPs to liquid cultures of A. fumigatus increased their secretion of gliotoxin by up to 65% after seven days of incubation. This demonstrates that there is a correlation between the presence of PAMPs and the secretion of gliotoxin. Gliotoxin is an epipolythiodioxopiperazin and a secondary Coptisine-chloride metabolite from A. fumigatus with a characteristic disulfide bridge which is essential for its activity. Gliotoxin is a product of the gli non-ribosomal peptide synthetase gene cluster and its biosynthesis regulated by transcript factors from gliZ, gliI, and gliP. This study, however, does not differentiate between secretion and regulation of biosynthesis. The available data on the A. fumigatus genome have recently been reviewed, showing that most of its receptors have yet to be characterized. Based on our findings, it is possible that one or more of these uncharacterized receptors may be sensitive to PAMPs. Furthermore, li le is known about the interaction between fungi and bacteria. Even less is known of the underlying factors of elicitation in fungi, and the effects of PAMPs on fungal metabolism and growth have not yet been described. While there may conceivably be several receptors that are involved in these PAMP recognition pathways, our results suggest that they are governed by a mutual feedback system or exhibit some degree of mutual saturation in signal transduction because the additive effect of different PAMPs is weak and not discernible at higher concentrations. PRRs in plants and mammals detect microbial pathogens, causing the activation of host defense systems and immunomodulatory responses. Many microbe-associated molecular pa erns exist, but their interactions with plant PRRs have yet to be characterized. For mammals, in general, the TLR4 receptor binds to the lipid A moiety of LPS while the TLR2 receptor detects PG and LTA. However, fungi-associated molecular pa erns such as zymosan, b-glycan and mannan are also detected via TLR2 and TLR4. If A. fumigatus does express proteins analogous to the TLR-like receptors, these must somehow be able to distinguish between their own recognition substances and those of competing organisms. Although no known PAMPreceptor like proteins have yet been recognized in fungal genomes, our results indicate that at least in the case of A. fumigatus, there are PAMP detection systems whose activation can increase the secretion of specific metabolites �C in our case gliotoxin. Although there are examples of new compounds identified with help of bacterial and fungal co-cultivation, there has been no previous study on the effect of individual PAMPs on fungal metabolism. The ubiquitous bacterial molecules used as PAMPs in this study could possibly be universal stimuli for the production of antimicrobial agents by most organisms. While the traditional approach to drug discovery does not use any such stimulation.