Pathogenic fungi-induced susceptibility is mitigated by mutual Lactobacillus plantarum in the Drosophila melanogaster model
Abstract Background Animals frequently encounter a variety of harmful fungi in the wild, but their ability to develop sophisticated anti-fungal strategies allows them to flourish across the globe. Extensive studies have highlighted significant involvement of indigenous microbial communities in host health, but the daunting complexity of microflora has hampered our understanding of the intricate relationships among them. In this work, we sought to develop a bacterium-fungus-Drosophila model that offered a model to systematically evaluate the anti-fungal effects of commensal bacteria. Results We isolated a pathogenic fungal strain, Diaporthe FY, that was detrimental to the survival and development of Drosophila upon infection. Using Drosophila as a model system, Drosophila-associated Lactobacillus plantarum functioned as a probiotics, and protected flies from mortality induced by Diaporthe FY. Our results shown that L. plantarum hindered the growth of Diaporthe FY in vitro, and decreased the mortality rate of Diaporthe FY-infected flies in vivo, therefore consequently mitigating the toxicity of Diaporthe FY to hosts. In addition, L. plantarum overrode the avoidance of oviposition on Diaporthe FY-associated substrates. Conclusions Diaporthe FY was identified as a potential pathogen to Drosophila. Commensal L. plantarum mitigated the pathogenic fungi-induced susceptibility in Drosophila, providing an insight into the natural interplays between commensal and pathogenic microbial communities that contribute to animal health and pathogenesis.