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Soil environment contaminated by Escherichia coli O157:H7 which come from the waste of infected animals. Earthworms can live in the pathogens-polluted soil by their innate immunity. How the proteins of earthworms E. fetida will response to E. coli O157:H7-contaminated-soil still unclear? To identify the defense proteins under E. coli O157:H7 stress, we performed a proteomic analysis of earthworm under E. coli O157:H7 exposure through an iTRAQ technology. In total, we found 283 non-redundant proteins, including fibrinolytic protease 1, lombricine kinase, lysozyme, gelsolin, coelomic cytolytic factor-1, antimicrobial peptide lumbricin-l, lysenin, and et al. The proteins participate in metabolic processes, transcription, defense response to bacterium, translation, response to stress, and transport. The study will contribute to understand why earthworm can live in the pathogens-polluted environment. [ABSTRACT FROM AUTHOR]

The transition metal cadmium is a pervasive and persistent environmental contaminant that is both a human toxicant and a carcinogen. To inhibit cadmium-induced damage, cells increase the expression of genes encoding stress-response proteins. The transcription of many stress-responsive genes, including those that encode metallothioneins, glutathione-S-transferases (GSTs) and heat shock proteins have been reported. The aim of this work was to investigate in Eisenia fetida the genes whose expressions are regulated following exposure to cadmium. mRNA differential display reverse transcription-polymerase chain reaction was used to analyze gene expression in E. fetida exposed to 50mg/l cadmium solution. Among the derived cDNA clones sequenced, we found 15 genes up-regulated and 12 down-regulated in response to cadmium exposure. The translated amino acid sequences of eight clones were similar to the Lumbricus terrestris hemoglobin dodecamer, Tribolium castaneum membrane protein, Escherichia coli UMN026 DNA-binding transcriptional activator, Brugia malayi immunoglobulin, Homo sapiens cell growth-inhibiting protein, Apis mellifera poly U binding factor, Escherichia fergusonii copper transporter, and the mRNA that encodes E. coli K-12 cytoplasmic insertase into membrane protein. Five cDNA fragments presented no homology with known gene sequences, suggesting that these sequences may either encode proteins not yet identified or correspond to untranslated regions of mRNA molecules. In-depth functional analyses of these genes are needed to reveal their exact roles. [Copyright &y& Elsevier]

Abstract: Escherichia coli O157:H7 is an intestine-inhabiting bacterium associated with many severe disease outbreaks worldwide. It may enter the soil environment with the excreta of infected animals (including horses, cattle and chickens) and human. Earthworms are able to protect themselves against invading pathogens due to their efficient innate defense system. To better understand the mechanisms earthworms (Eisenia fetida) utilize to defend and eliminate Escherichia coli O157:H7, we examined the changes in the growth rate, as well as antioxidant and antimicrobial functions of earthworms in response to various concentrations of Escherichia coli O157:H7 in an artificial soil. Our results show that earthworms can inhibit the growth of Escherichia coli O157:H7. Upon exposure to Escherichia coli O157:H7 from 0d to 24d, coelomic cytolytic factor (CCF) in earthworms is induced, the reactive oxygen species (ROSs) and superoxide dismutase (SOD) are also elevated. Under lower bacterial concentrations (105–106 CFUg−1), these ROSs can be rapidly scavenged by superoxide dismutase (SOD) to avoid peroxidation damage, but when the bacterial concentrations are high (107–108 CFUg−1), excess amount of ROSs then cause accumulation of lipid peroxidation molecular malondialdehyde (MDA). In addition, exposure to Escherichia coli O157:H7 can induce the gene expression of antimicrobial peptide lumbricin I in the tissues of the earthworms. In conclusion, antioxidant systems and antimicrobial immune function may play important roles in the defense of the earthworms Eisenia fetida against Escherichia coli O157:H7. [Copyright &y& Elsevier]

Abstract: The experiment was conducted to study earthworm (Eisenia fetida) polysaccharides and their antibacterial function on plant-pathogen microbes in vitro. The following results were obtained. (1) Polysaccharides isolated from common earthworms and induced earthworms had broad-spectrum antibacterial activities on plant-pathogen microbes in vitro. (2) Antibacterial activities of earthworm polysaccharides were assayed by the Disk method. The diameter of bacteriostasis circle to Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Pseudomonas solanacearum Smith, Sclerotinia sclerotiorum, Colletotrichum lagenarium, Fusarum oxysporum, Phytophthora boehmeriae Sawada, Rhizoctonia solani Kühn and Botrytis cinerea was 2.10±0.08, 2.33±0.05, 3.30±0.08, 4.28±0.10, 4.15±0.06, 1.53±0.05, 2.15±0.06, 4.58±0.10, 2.40±0.08, and 2.48±0.10cm, respectively. (3) Antibacterial function of mucopolysaccharide for Pseudomonas aeruginosa and Staphylococcus aureus increased significantly (P <0.05) after earthworms were induced by Escherichia coli, while minimum inhibitory concentrations (MIC) did not change for Escherichia coli. (4) The antibacterial component of polysaccharides isolated from both earthworms and induced earthworms were composed of five molecules by HPLC-MS. The composition at retention time 5.3min was Glu-Xyl-Glu-Xyl, with a molecular weight of 533Da, while that at 6.0min was 452Da, which was composed of Glu-Rha-Rha or Rha-Glu-Rha. The molecular weight of the 6.7min composition was 678Da, which was composed of Glu-Glu-Glu-Xyl-Xyl. [Copyright &y& Elsevier]

Abstract: In order to investigate the activity of peptides in earthworm tissue and coelomic fluid, we established the peptide separation and purification method in our laboratory. Six antimicrobial peptides were isolated and purified from earthworm tissue liquid homogenate and coelomic fluid, which contained 5–50 amino acid (AA) residues with the same or similar sequence of Ala-Met-Val-Ser-Gly, and named the antibacterial vermipeptides family (AVPF) according to their structure and antibacterial characteristics. In this paper, we introduced a general protocol of AVPF peptide preparation methods from earthworms, including crude peptide preparation and purification by ultrafiltration, ion-exchange chromatography, gel-filtration and HPLC chromatography. The AVPF includes a wide antibacterial spectrum and speciality, performs antimicrobial activities not only to Gram-positive and Gram-negative bacteria but also to fungi. Multi-functions of some peptides of AVPF have been reported. As an example, the resistance of EP3 and EP5 of AVPF to cancer cells, HeLa and MGC803 has been reported. EP5 caused apoptosis of HeLa cell. The threshold value of EP3 that causes apoptosis of HeLa cells was 0.75mg/mL with an apoptotic rate of 48.12%. MGC803 cells showed significant morphological changes when the cells were attached by EP3. Short peptides with 5–7 amino acid residues formed multimers in the PB buffer, a more likely explanation for the antibacterial mechanism of short peptides that causes MGC803 cells to break. The antiviral effect of antimicrobial peptides (EP5) on the pseudorabies virus (PRV) was analyzed using the cytopathic effect (CPE) inhibition test. Results showed that EP5 inhibited the CPE by PRV on BHK cells. The mechanism of antiviral activity of EP5 may be explained by inhibiting the duplication of viral DNA. [Copyright &y& Elsevier]

Abstract: In this study, suppression subtractive hybridization was used to construct forward and reverse cDNA libraries to identify genes involved in the response of Eisenia fetida after exposure to Escherichia coli O157:H7. We cloned 1428 cDNAs or expressed sequence tags (ESTs), of which 738 were confirmed to be differentially expressed on dot blotting analysis. A total of 394 good-quality ESTs (GenBank dbEST accession numbers HO001170–HO001563) were obtained from the raw clone sequences after cleaning. The genes were associated with metabolism (10%), transport (10%), translation (5%), immunity (2%), and the cytoskeleton (1%). Thirteen candidates were selected to assess expression levels in earthworms exposed to artificially contaminated soil by real-time PCR. The translated amino acid sequences of clones were similar to fibrinolytic protease 1, extracellular globin-3, myosin essential light chain, lumbrokinase, lysozyme, ferritin, ATP synthase F0 subunit 6, and hsp 70. Characterization of differential gene expression in the earthworm E. fetida on exposure to E. coli O157:H7 expands our understanding of the molecular mechanisms of interactions at the earthworm–pathogen interface. [Copyright &y& Elsevier]

• Earthworm weight and cocoon production decreased significantly after exposure to petroleum-contaminated soil. • High concentrations of petroleum can cause damage to the DNA within earthworm seminal vesicles. • Oxidative stress was induced by petroleum-contaminated soil. • mRNA levels of annetocin precursor, a reproduction-related gene, was significantly inhibited after petroleum exposure. • mRNA levels of TCTP and SOD exhibited a concentration-dependent relationship. Petroleum is an important industrial raw material that enters the soil during production and use and is harmful to soil organisms. To evaluate the toxicity of petroleum-contaminated soil, earthworms (Eisenia fetida) were used as model organisms for soil ecotoxicity studies. We found that earthworm weight and cocoon production decreased significantly after exposure to petroleum-contaminated soil. In addition, soil contaminated with high concentrations of petroleum can cause damage to the DNA within earthworm seminal vesicles. Superoxide dismutase (SOD), catalase, and peroxidase activities were significantly inhibited when earthworms were exposed to petroleum-contaminated soil, indicating that oxidative stress was induced by petroleum pollutants. The mRNA levels of annetocin precursor , a reproduction-related gene, was significantly inhibited after petroleum exposure. The mRNA levels of translationally controlled tumour protein (TCTP) and SOD exhibited a concentration-dependent relationship, and their relative expression increased with petroleum concentration. [ABSTRACT FROM AUTHOR]