The massive production and use of silver nanoparticles (Ag NPs) have led to their increasing release into the environment. Even though the antimicrobial and cytotoxic effects of native nanoparticles have been well studied, the environmental impacts of transformation products such as silver sulfide nanoparticles (Ag2S NPs) have not been elucidated. In the present study, we assessed the toxicity of Ag2S NPs and silver nitrate (AgNO3), as a source of Ag, to the earthworm Eisenia andrei using a nominal concentration of 5 mg Ag kg-1 soil. We used the OECD guidelines to assess effects on weight loss and mortality for 14 days. After exposure, we also extracted the immune effector cells (coelomocytes) and conducted a battery of biomarker tests. To ensure the quality of the toxicological results, the structural changes of NPs during the experiment and the uptake of silver by the earthworms were monitored. During the experiment, mortality effects were not detected, but a weight loss was observed in the earthworms exposed to Ag2S NPs. Altough Ag2S NPs were engulfed by E. andrei cells, neither phenoloxidase activity nor lipid peroxidation differed from the untreated control group. Cells from earthworms treated with Ag2S NPs exerted very broad value range of nitric oxide (NO) generation, suggesting an imbalance in the NO metabolism. Overall, this study suggests minimal risks associated with Ag2S NPs exposure to earthworms. However, further studies are needed to assure no immunotoxicological or chronic effects on a wider range of terrestrial organisms.

• MeSH
• dusičnan stříbrný toxicita   MeSH
• hmotnostní úbytek MeSH
• kovové nanočástice * chemie   toxicita   MeSH
• látky znečišťující půdu * toxicita   MeSH
• Oligochaeta * MeSH
• půda chemie   MeSH
• sloučeniny stříbra MeSH
• stříbro metabolismus   toxicita   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Earthworms are not endowed with adaptive immunity and they are rely on the tools of innate immunity. Cells of the innate immune system utilize pattern recognition receptors, such as Toll-like receptors, to detect the pathogen-associated molecular patterns (PAMPs). The first earthworm TLR was isolated from Eisenia andrei earthworms (EaTLR), which belongs to the single cysteine cluster TLR (sccTLR). Here, we identified a new multiple cysteine cluster TLR (mccTLR) in E. andrei earthworms. Phylogenetic DNA analysis revealed that it has no variability within one earthworm as well as in the population. By screening of the tissue expression profile, the TLR was expressed primarily in earthworm seminal vesicles and receptacles suggesting a connection to sperm cells. Seminal vesicles are often heavily infected by gregarine parasites. As a sign of immune response, a strong melanization reaction is visible around parasites. Stimulation experiments with profilin from related parasite Toxoplasma gondii, led to the upregulation of mccEaTLR in the earthworm seminal vesicles. Also, profilin activated prophenoloxidase cascade, the efficient mechanism of innate immunity. However, its involvement in the NF-κB signaling was not proven. Further, we provide evidence that the antibiotics metronidazole and griseofulvin destroyed the developing spermatocytes. The observed decrease in the mccEaTLR mRNA levels after the antibiotic treatment of parasites is caused by the decline of sperm cells numbers rather than by diminution of the parasites. Since earthworms with extensively reduced parasite load had a similar amount of mccEaTLR mRNA, presumably, earthworm sperm cells have a certain level of mccEaTLR expressed as a standard, which can be augmented by particular antigenic stimulation. Also, mccEaTLR was expressed mainly in the early stages of earthworm development and presumably is primarily involved in early embryonic development. Expression of mccEaTLR in seminal vesicles correlates with the expression of endothelial monocyte-activation polypeptide II. High-throughput sequencing of gregarine DNA from seminal vesicles of individual earthworms resulted in great diversity of the observed genotypes. Phylogenetically, all observed OTUs belong to the clade of earthworm gregarines suggesting host specificity. Overall, mccEaTLR is supposed to play a function role in early embryonic development and potentially it participates in immune response against parasites.

• MeSH
• cystein MeSH
• cytokiny imunologie   MeSH
• embryonální vývoj imunologie   MeSH
• fylogeneze MeSH
• messenger RNA imunologie   MeSH
• nádorové proteiny imunologie   MeSH
• NF-kappa B imunologie   MeSH
• Oligochaeta imunologie   MeSH
• přirozená imunita imunologie   MeSH
• proteiny vázající RNA imunologie   MeSH
• receptory rozpoznávající vzory imunologie   MeSH
• signální transdukce imunologie   MeSH
• toll-like receptory imunologie   MeSH
• Toxoplasma imunologie   MeSH
• upregulace imunologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Vermicomposting is a process of degradation of biowaste which involves complex interactions between earthworms and microorganisms. This process lacks a thermophilic stage and thus, the possible presence of pathogens poses a potential health hazard. To assess the contribution of earthworms during the selective reduction of various pathogens, apple pomace substrate was artificially inoculated with Escherichia coli, Salmonella spp., thermotolerant coliform bacteria, and Enterococci. The artificial bacterial load did not influence the weight, reproduction, or intestinal enzymatic activity of the earthworms, but it caused reversible histological changes to the epithelial layer and chloragogen tissue of their intestines. The reduction of pathogenic Enterococci and E. coli from the substrate was accelerated by earthworms (63-fold, 77-fold, and 840-fold for Enterococci and 6-fold, 36-fold, and 7-fold for E. coli inoculated substrates after 2, 4, and 6 weeks, respectively). Moreover, the rapid elimination of Salmonella spp. was supported by the upregulated expression of two pattern recognition receptors which bind lipopolysaccharide, coelomic cytolytic factor, and lipopolysaccharide-binding protein. Further, the microbiomes of the intestine and the composting substrate differed significantly. Graphical abstract.

• MeSH
• Escherichia coli MeSH
• kompostování metody   MeSH
• Oligochaeta mikrobiologie   fyziologie   MeSH
• půdní mikrobiologie * MeSH
• střevní mikroflóra * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH