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Background: Mucormycetes, a heterogeneous group of fungi, induce a life-threatening disease called mucormycosis. Immune deficiencies represent a major risk factor; hence, we wanted to illuminate the role of complement and platelets in the defense against mucormycetes. Methods: Rhizopus arrhizus (Ra), Rhizopus microsporus (Rm), Lichtheimia ramosa (Lr), Lichtheimia corymbifera (Lc), Rhizomucor pusillus (Rmp), and Mucor circinelloides (Mc) spores were opsonized with human and mouse serum, and C1q, C3c, and terminal complement complex (C5b-9) deposition was measured. Additionally, thrombocytopenic, C3-deficient, or C6-deficient mice were intravenously infected with selected isolates. Survival and immunological parameters were monitored, and fungal burden was determined and compared to that of immunocompetent and neutropenic mice. Results: In vitro experiments showed significant differences in complement deposition between mucormycetes. Mc isolates bound up to threefold more human C5b-9 than other mucormycetes. Lr, Lc, and Mc bound high levels of murine C3c, whereas human C3c deposition was reduced on Mc compared to Lr and Lc. Murine C3c deposition negatively correlated with virulence. Complement deficiencies and neutropenia, but not thrombocytopenia, were shown to be a risk factor for a lethal outcome. Conclusion: Complement deposition varies between mucormycetes. Additionally, we demonstrated that complement and neutrophilic granulocytes, but not platelets, play an important role in a murine model of disseminated mucormycosis. [ABSTRACT FROM AUTHOR]

Candidiasis is common in diabetic patients. Complement evasion is facilitated by binding complement factor H (FH). Since the expression of high-affinity glucose transporter 1 (Hgt1), a FH-binding molecule, is glucose-dependent, we aimed to study its relevance to the pathogenesis of Candida albicans. Euglycemic and diabetic mice were intravenously challenged with either Candida albicans lacking Hgt1 (hgt1-/-) or its parental strain (SN152). Survival and clinical status were monitored over 14 days. In vitro, Candida albicans strains were grown at different glucose concentrations, opsonized with human serum, and checked for C3b/iC3b and FH deposition. Phagocytosis was studied by fluorescein isothiocyanate-labeled opsonized yeast cells incubated with granulocytes. The murine model demonstrated a significantly higher virulence of SN152 in diabetic mice and an overall increased lethality of mice challenged with hgt1-/-. In vitro lower phagocytosis and C3b/iC3b deposition and higher FH deposition were demonstrated for SN152 incubated at higher glucose concentrations, while there was no difference on hgt1-/- at physiological glucose concentrations. Despite C3b/iC3b and FH deposition being glucose-dependent, this effect has a minor influence on phagocytosis. The absence of Hgt1 is diminishing this dependency on complement deposition, but it cannot be attributed to being beneficial in a murine model. [ABSTRACT FROM AUTHOR]

• Landscape had a lower effect on aphids and their parasitoids than fertilisation. • Fertilisation affected plants positively. • Fertilisation affected aphids and primary parasitism rate negatively. • Fertilisation had no effect on secondary parasitism rate. • H 2 ' and generality between parasitoids are affected by landscape and fertilisation. Agricultural intensification can impact agrobiodiversity in several ways such as in terms of population densities, community composition and food web interactions across all trophic levels. This effect can be investigated at two scales: field-scale and landscape scale. Here it was assessed how the impact of fertilisation (within field) and landscape complexity (within landscape) impact cereal aphid-primary parasitoid-secondary parasitoid systems in winter wheat in Germany. A newly developed molecular technique was used to quantify species-specific linkages between aphids, primary parasitoids and secondary parasitoids sampled in fertilised and unfertilised plots in either simple or complex structured landscapes. The results show a stronger effect of fertilisation than landscape complexity on the groups: fertilisation positively affected the crop plants while it negatively affected both the density of the cereal aphid Sitobion avenae and its primary parasitism rates whereas no effect on the level of secondary parasitism rates was observed. Landscape complexity had no effect on plants, aphids, as well as on primary parasitism rate. In case of secondary parasitism rate there was an effect in interaction with sampling date. Field identity accounted for the strongest effect on parasitoid community composition (10.6% of the variance) from all tested variables, while fertilisation and landscape complexity had almost no effect (1.1% and no effect). Nevertheless, a weak cascading effect of both environmental factors could be observed as the primary-secondary parasitoid network structure responded to both. However, these observed effects on food webs strongly depended on species identity, highlighting the need of species-level food web assessment. [ABSTRACT FROM AUTHOR]