Objective: To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis. Methods: The puochitis rat model was established and the faeces sample and the mucous membrane sample were collected regul...Objective: To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis. Methods: The puochitis rat model was established and the faeces sample and the mucous membrane sample were collected regularly, in which the bacterial nucleic acids were extracted for quantitative analysis of the intestinal flora in the samples through using the real-time quantitative PCR technique and high energy sequencing technology. Results: The disorder phenomenon of the intestinal flora appeared at the 7th day of the experiment, and the pouchitis was presented at the 21 th day of the experiment. At the 31 th day of the experiment, compared to control group and non-pouchitis group, the quantity of Bifidobacterium and the Lactobacillusof the pouchitis model rats in the mucous membrane sample and the faeces sample were significantly decreased(P<0.05), and the Bacteroidetes, Faecalibacterium prausnitzii and 桛 Clostridium leptum subgroup in the mucous membrane of pouchitis were significantly decreased(P<0.05). The Clostridium coccoides group was the main flora in the mucous membrane of pouchitis, the bacterial diversity of non-puochitis group and control group was significantly higher than that of the puochitis group(P<0.05). Conclusions: The intestinal flora imbalance is one of the factors that cause the incidence of the pouhitis; this study provides a clue of the pathogenesis and treatment direction of the intestinal inflammatory disease.展开更多
From nodules of perennial xerophyte desert leguminous plants – Ammodendron conollyi, Astragalus villossimus, Astragalus unifoliolatus – 151 bacterial isolates have been isolated. The study of nodulation showed that ...From nodules of perennial xerophyte desert leguminous plants – Ammodendron conollyi, Astragalus villossimus, Astragalus unifoliolatus – 151 bacterial isolates have been isolated. The study of nodulation showed that AC8-1, AC11, AC21, AC1-1, AC12-1 isolates (from Ammodendron conollyi), AV1, AV8-1, AV9, AV26-1, AV36-1 isolates (from Astragalus villossimus) and AU17-1, AU30-1, AU30-2, AU20-1, AU23 isolates (from Astragalus unifoliolatus) formed an effective nitrogen-fixing symbiosis with the host plants. As a result of 16S rRNA gene study of the salt-resistant nodule bacteria it has been determined that bacteria were related to Rhizobium, Burkholderia and Achromobacter genera. The study of isolates growth has revealed that there were fast-growing and moderately-grow- ing isolates that possessed with doubling-time varying from 20 to 45 min. Their examination for antibiotic-resistance showed that the number of bacterial colonies of selected strains decreased to some extent in the presence of chloramphenicol, but in all strains the resistance to antibiotics was detected. The further investigations of resistance of the formed symbiosis to stresses (drought, salinity) showed that at 6.41% of moisture the maximal height and biomass of inoculated plants of Ammodendron conollyi were 21 cm and 2320 mg, but at 3.8% moisture the height reduced by 4 times (up to 4.5 cm) and the biomass – by 11 times (203 mg). The analogous effect was observed in Astragalus villossimus and Astragalus unifoliolatus symbiosises. The salinity equal to 100-200 mM NaCl did not affect practically on normal growth and development of desert leguminous plants symbiosis, while for Astragalus villossimus such affecting concentration comprised up to 100 mM NaCl. The light microscopy and electron microscopy of Astragalus villossimus nodule sections showed that V1 nodule bacteria strain efficiently colonized the internal space within nodules, where they were transformed into bacteroids. At 100 mM NaCl salinity concentration the colonization of nodule ba展开更多
Rhizobia interact with host legumes to induce the formation of nitrogen-fixing nodules,which is very important in agriculture and ecology.The development of nitrogen-fixing nodules is stringently regulated by host pla...Rhizobia interact with host legumes to induce the formation of nitrogen-fixing nodules,which is very important in agriculture and ecology.The development of nitrogen-fixing nodules is stringently regulated by host plants and rhizobial symbionts.In our previous work,a new Sinorhizobium meliloti LysR regulator gene(lsrB)was identified to be essential for alfalfa nodulation.However,how this gene is involved in alfalfa nodulation was not yet understood.Here,we found that this gene was associated with prevention of premature nodule senescence and abortive bacteroid formation.Heterogeneous deficient alfalfa root nodules were induced by the in-frame deletion mutant of lsrB(lsrB1-2),which was similar to the plasmid-insertion mutant,lsrB1.Irregular senescence zones earlier appeared in these nodules where bacteroid differentiation was blocked at different stages from microscopy observations.Interestingly,oxidative bursts were observed in these nodules by DAB staining.The decreased expression of lipopolysaccharide core genes(lpsCDE)was correspondingly determined in these nodules.S.meliloti lipopolysaccharide is required for suppression of oxidative bursts or host cell defense.These findings demonstrate that the S.meliloti lsrB gene is involved in alfalfa root nodule development and bacteroid differentiation by suppressing oxidative bursts or defense responses in host cells.展开更多
基金supported by Natural Science Foundation of China(Grant Number:8150041674)
文摘Objective: To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis. Methods: The puochitis rat model was established and the faeces sample and the mucous membrane sample were collected regularly, in which the bacterial nucleic acids were extracted for quantitative analysis of the intestinal flora in the samples through using the real-time quantitative PCR technique and high energy sequencing technology. Results: The disorder phenomenon of the intestinal flora appeared at the 7th day of the experiment, and the pouchitis was presented at the 21 th day of the experiment. At the 31 th day of the experiment, compared to control group and non-pouchitis group, the quantity of Bifidobacterium and the Lactobacillusof the pouchitis model rats in the mucous membrane sample and the faeces sample were significantly decreased(P<0.05), and the Bacteroidetes, Faecalibacterium prausnitzii and 桛 Clostridium leptum subgroup in the mucous membrane of pouchitis were significantly decreased(P<0.05). The Clostridium coccoides group was the main flora in the mucous membrane of pouchitis, the bacterial diversity of non-puochitis group and control group was significantly higher than that of the puochitis group(P<0.05). Conclusions: The intestinal flora imbalance is one of the factors that cause the incidence of the pouhitis; this study provides a clue of the pathogenesis and treatment direction of the intestinal inflammatory disease.
文摘From nodules of perennial xerophyte desert leguminous plants – Ammodendron conollyi, Astragalus villossimus, Astragalus unifoliolatus – 151 bacterial isolates have been isolated. The study of nodulation showed that AC8-1, AC11, AC21, AC1-1, AC12-1 isolates (from Ammodendron conollyi), AV1, AV8-1, AV9, AV26-1, AV36-1 isolates (from Astragalus villossimus) and AU17-1, AU30-1, AU30-2, AU20-1, AU23 isolates (from Astragalus unifoliolatus) formed an effective nitrogen-fixing symbiosis with the host plants. As a result of 16S rRNA gene study of the salt-resistant nodule bacteria it has been determined that bacteria were related to Rhizobium, Burkholderia and Achromobacter genera. The study of isolates growth has revealed that there were fast-growing and moderately-grow- ing isolates that possessed with doubling-time varying from 20 to 45 min. Their examination for antibiotic-resistance showed that the number of bacterial colonies of selected strains decreased to some extent in the presence of chloramphenicol, but in all strains the resistance to antibiotics was detected. The further investigations of resistance of the formed symbiosis to stresses (drought, salinity) showed that at 6.41% of moisture the maximal height and biomass of inoculated plants of Ammodendron conollyi were 21 cm and 2320 mg, but at 3.8% moisture the height reduced by 4 times (up to 4.5 cm) and the biomass – by 11 times (203 mg). The analogous effect was observed in Astragalus villossimus and Astragalus unifoliolatus symbiosises. The salinity equal to 100-200 mM NaCl did not affect practically on normal growth and development of desert leguminous plants symbiosis, while for Astragalus villossimus such affecting concentration comprised up to 100 mM NaCl. The light microscopy and electron microscopy of Astragalus villossimus nodule sections showed that V1 nodule bacteria strain efficiently colonized the internal space within nodules, where they were transformed into bacteroids. At 100 mM NaCl salinity concentration the colonization of nodule ba
基金supported by National Basic Research Program of China (2010CB126501, 2011CB100702)the National Natural Science Foundation of China (31070218)
文摘Rhizobia interact with host legumes to induce the formation of nitrogen-fixing nodules,which is very important in agriculture and ecology.The development of nitrogen-fixing nodules is stringently regulated by host plants and rhizobial symbionts.In our previous work,a new Sinorhizobium meliloti LysR regulator gene(lsrB)was identified to be essential for alfalfa nodulation.However,how this gene is involved in alfalfa nodulation was not yet understood.Here,we found that this gene was associated with prevention of premature nodule senescence and abortive bacteroid formation.Heterogeneous deficient alfalfa root nodules were induced by the in-frame deletion mutant of lsrB(lsrB1-2),which was similar to the plasmid-insertion mutant,lsrB1.Irregular senescence zones earlier appeared in these nodules where bacteroid differentiation was blocked at different stages from microscopy observations.Interestingly,oxidative bursts were observed in these nodules by DAB staining.The decreased expression of lipopolysaccharide core genes(lpsCDE)was correspondingly determined in these nodules.S.meliloti lipopolysaccharide is required for suppression of oxidative bursts or host cell defense.These findings demonstrate that the S.meliloti lsrB gene is involved in alfalfa root nodule development and bacteroid differentiation by suppressing oxidative bursts or defense responses in host cells.
