RÉSUMÉ
Objective To investigate the bacterial community diversity in Dermatophagoides farinae. Methods Laboratory-cultured D. farinae was collected, and the composition of microbial communities was determined by sequence analyses of the V4 region in the bacterial 16S ribosomal RNA (16S rRNA) gene on an Illumina PE250 high-throughput sequencing platform. Following quality control and filtering of the raw sequence files, valid reads were obtained and subjected to operational taxonomic units (OTU) clustering and analysis of the composition of microbial communities and alpha diversity index using the Usearch software, Silva database, and Mothur software. Results A total of 187 616 valid reads were obtained, and 469 OTUs were clustered based on a sequence similarity of more than 97%. OTU annotation showed that the bacteria in D. farinae belonged to 26 phyla, 43 classes, 100 orders, 167 families and 284 genera. The bacteria in D. farinae were mainly annotated to five phyla of Proteobacteria, Firmicutes, Bacteroidota, Actinobacteriota, and Acidobacteriota, with Proteobacteria as the dominant phylum, and mainly annotated to five dominant genera of Ralstonia, norank-f-Mitochondria, Staphylococcus and Sphingomonas, with Wolbachia identified in the non-dominant genus. Conclusions A high diversity is identified in the composition of the bacterial community in D. farinae, and there are differences in bacterial community diversity and abundance among D. farinae.
RÉSUMÉ
Objective To evaluate the effects of Cu2+ and Cd2+ at different concentrations on superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity in Oncomelania hupensis. Methods Cu2+- and Cd2+-containing solutions were prepared at 7 concentrations, and O. hupensis snails were exposed to the solutions for 24 h, of 15 snails in each concentration. Then, the snail body was collected following removal of the snail shell and homogenated, and the SOD, CAT and POS activities were detected in the supernatants. Results With the increase of the Cu2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline-rise-decline tendency, while the POD activity showed a tendency towards rise followed by decline. With the increase of the Cd2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline- rise- decline tendency, while the POD activity showed a decline-rise-decline tendency. Conclusion Exposure to Cu2+ and Cd2+ at high concentrations results in a decline in the activity of SOD, CAT and POD in O. hupensis at the same time.
RÉSUMÉ
Objective To detect the molecular characterization of polysaccharide purified from Amusium pleuronectes, so as to investigate its role of intervention to the formation of hepatic fibrosis caused by Schistosoma japonicum infection. Methods The crude polysaccharide from A. pleuronectes was extracted and further purified, and the molecular weight and monosaccharide composition were determined by the high pressure size exclusion chromatography and PMP pre-column derivatization method, respectively. A total of 50 female BALB/c mice were randomly divided into five groups：A (normal group), B (experimental group), C (polysaccharide group), D (praziquantel), and E (polysaccharide + praziquantel group). The mice in B, C, D, or E groups were attacked on the abdominal skin by using the cercariae of S. japonicum (30 ± 2 for each mouse) respectively. After 8 weeks, the mice in C, D, and E groups were administrated by polysaccharide and/or praziquantel, and the mice in B group were instead of saline. All the livers and sera were collected after 16 weeks. HE staining was employed for the livers, and serum IFN-γ and IL-13 were measured by using ELISA kits. Results The molecular weight of purified polysaccharide from A. pleuronectes was 11.7 kDa. Compared with A and B groups, the serum levels of IFN-γ in C, D, and E groups were significantly increased (F = 63.525, P < 0.01). However, the serum levels of IL-13 in C, D, and E groups were significantly decreased (F = 99.788, P < 0.01) compared with that in B group. HE staining showed that the egg nodules and hepatic fibrosis were observed in B, C, D, and E groups. The number of egg nodules and fibrosis degree in E group were milder than those in B group (χ2 = 7.875, P < 0.05). Conclusions The polysaccharide from A. pleuronectes has an obvious effect in preventing hepatic fibrosis process induced by S. japonicum infection, particularly combining with the administration of praziquantel.
RÉSUMÉ
Objective To detect the molecular characterization of polysaccharide purified from Amusium pleuronectes, so as to investigate its role of intervention to the formation of hepatic fibrosis caused by Schistosoma japonicum infection. Methods The crude polysaccharide from A. pleuronectes was extracted and further purified, and the molecular weight and monosaccharide composition were determined by the high pressure size exclusion chromatography and PMP pre-column derivatization method, respectively. A total of 50 female BALB/c mice were randomly divided into five groups：A (normal group), B (experimental group), C (polysaccharide group), D (praziquantel), and E (polysaccharide + praziquantel group). The mice in B, C, D, or E groups were attacked on the abdominal skin by using the cercariae of S. japonicum (30 ± 2 for each mouse) respectively. After 8 weeks, the mice in C, D, and E groups were administrated by polysaccharide and/or praziquantel, and the mice in B group were instead of saline. All the livers and sera were collected after 16 weeks. HE staining was employed for the livers, and serum IFN-γ and IL-13 were measured by using ELISA kits. Results The molecular weight of purified polysaccharide from A. pleuronectes was 11.7 kDa. Compared with A and B groups, the serum levels of IFN-γ in C, D, and E groups were significantly increased (F = 63.525, P < 0.01). However, the serum levels of IL-13 in C, D, and E groups were significantly decreased (F = 99.788, P < 0.01) compared with that in B group. HE staining showed that the egg nodules and hepatic fibrosis were observed in B, C, D, and E groups. The number of egg nodules and fibrosis degree in E group were milder than those in B group (χ2 = 7.875, P < 0.05). Conclusions The polysaccharide from A. pleuronectes has an obvious effect in preventing hepatic fibrosis process induced by S. japonicum infection, particularly combining with the administration of praziquantel.