Project description:Polyethylene pollutions are considered inert in nature and adversely affect the entire ecosystem. Larvae of greater wax moths (Galleria mellonella) have the ability to masticate and potentially biodegrade polyethylene films at elevated rates. The wax moth has been thought to metabolize PE independently of gut flora, however, the role of the microbiome is poorly understood and degradation by the wax moth might be involved. To determine whether the salivary glands of the wax moth were potentially involved in the PE degradation, it was investigated how surface changes of polyethylene were affected by mastication and consumption. Formation of pitting and degradation intermediates, including carbonyl groups, indicated that salivary glands could assist in polyethylene metabolism. We investigated the biochemical effect of exposure to PE on the composition of the salivary gland proteome. The expression of salivary proteins was found to be affected by PE exposure. The proteins that were significantly affected by the exposure to PE revealed that the wax moth is undergoing general changes in energy levels, and that enzymatic pathways associated with fatty acid beta oxidation were induced during PE consumption.
Project description:Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative bacterial pathogen associated with severe periodontitis and non-oral diseases. Clinical isolates of Aa display a rough (R) colony phenotype with strong adherent properties. Upon prolonged culturing, non-adherent strains with a smooth (S) colony phenotype emerge. To date, most virulence studies on Aa have been performed with S strains of Aa, whereas the virulence of clinical R isolates received relatively little attention. Since the extracellular proteome is the main bacterial reservoir of virulence factors, the present study was aimed at a comparative analysis of this sub-proteome fraction for a collection of R isolates and derivative S strains, in order to link particular proteins to the virulence of Aa with serotype b. To assess the bacterial virulence, we applied different infection models based on larvae of the greater wax moth Galleria mellonella, a human salivary gland-derived epithelial cell line, and freshly isolated neutrophils from healthy human volunteers. A total number of 351 extracellular Aa proteins was identified by mass spectrometry, with the S strains consistently showing more extracellular proteins than their parental R isolates. A total of 50 known extracellular virulence factors was identified, of which 15 were expressed by all investigated bacteria. Importantly, the comparison of differences in exoproteome composition and virulence highlights critical roles of 10 extracellular proteins in the different infection models. Altogether, our present study provides novel cues for understanding the virulence of Aa, and for development of potential preventive or therapeutic avenues to neutralize this important oral pathogen.
Project description:Larvae of the greater wax moth Galleria mellonella are an ideal in vivo model to quickly and easily assess the virulence of a range of human pathogens, to comprehensively analyse the host – pathogen interactome and to reproducibly evaluate the in vivo toxicity and efficacy of anti-microbial agents. G. mellonella larvae are easy to inoculate, generate results within 48 hours and are free from the ethical and legal restrictions which surround the use of mammals for this type of testing.1,2 Microbial virulence and pathogenesis can be assessed by a variety of endpoints including survival, fluctuations in hemocyte density, oscillations in fungal burden and changes in hemolymph proteome. Insect hemocytes can be easily isolated and used in ex vivo cellular assays to determine phagocyte – pathogen interactions. Aspergillus fumigatus infection and dissimiation as well as G. mellonella cellular and humoral immune responses were analysed over 24 hours.
2018-06-21 | PXD008196 | Pride
Project description:Interplay between fungal infection and bacterial associates in wax moth Galleria mellonella