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Evidence for niche differentiation of nitrifying communities in grassland soils after 44 years of different field fertilization scenarios 认领
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作者 Zhongjun JIA Xue ZHOU +6 位作者 Weiwei XIA Dario FORNARA Baozhan WANG Elizabeth Anne WASSON Peter CHRISTIE Martin F.POLZ David D.MYROLD 《土壤圈:英文版》 SCIE CAS CSCD 2020年第1期87-97,共11页
Long-term nitrogen(N)fertilization imposes strong selection on nitrifying communities in agricultural soil,but how a progressively changing niche affects potentially active nitrifiers in the field remains poorly under... Long-term nitrogen(N)fertilization imposes strong selection on nitrifying communities in agricultural soil,but how a progressively changing niche affects potentially active nitrifiers in the field remains poorly understood.Using a 44-year grassland fertilization experiment,we investigated community shifts of active nitrifiers by DNA-based stable isotope probing(SIP)of field soils that received no fertilization(CK),high levels of organic cattle manure(HC),and chemical N fertilization(CF).Incubation of DNA-SIP microcosms showed significant nitrification activities in CF and HC soils,whereas no activity occurred in CK soils.The 44 years of inorganic N fertilization selected only 13C-ammonia-oxidizing bacteria(AOB),whereas cattle slurry applications created a niche in which both ammonia-oxidizing archaea(AOA)and AOB could be actively13C-labeled.Phylogenetic analysis indicated that Nitrosospira sp.62-like AOB dominated inorganically fertilized CF soils,while Nitrosospira sp.41-like AOB were abundant in organically fertilized HC soils.The 13C-AOA in HC soils were affiliated with the 29i4 lineage.The 13C-nitrite-oxidizing bacteria(NOB)were dominated by both Nitrospira-and Nitrobacter-like communities in CF soils,and the latter was overwhelmingly abundant in HC soils.The 13C-labeled nitrifying communities in SIP microcosms of CF and HC soils were largely similar to those predominant under field conditions.These results provide direct evidence for a strong selection of distinctly active nitrifiers after 44 years of different fertilization regimes in the field.Our findings imply that niche differentiation of nitrifying communities could be assessed as a net result of microbial adaption over 44 years to inorganic and organic N fertilization in the field,where distinct nitrifiers have been shaped by intensified anthropogenic N input. 展开更多
关键词 ammonia-oxidizing ARCHAEA ammonia-oxidizing BACTERIA community shift long-term FERTILIZATION nitrite-oxidizing BACTERIA nitrogen enrichment stable isotope probing MICROCOSM
Effect of transferring lignocellulose-degrading bacteria from termite to rumen fluid of sheep on in vitro gas production, fermentation parameters, microbial populations and enzyme activity 认领
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作者 Ayoub AZIZI Afrooz SHARIFI +3 位作者 Hasan FAZAELI Arash AZARFAR Arjan JONKER Ali KIANI 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第5期1323-1331,共9页
The digestive tract of termite(Microcerotermes diversus) contains a variety of lignocellulose-degrading bacteria with exocellulases enzyme activity, not found in the rumen, which could potentially improve fiber degrad... The digestive tract of termite(Microcerotermes diversus) contains a variety of lignocellulose-degrading bacteria with exocellulases enzyme activity, not found in the rumen, which could potentially improve fiber degradation in the rumen. The objectives of the current study were to determine the effect of inoculation of rumen fluid(RF) with three species of bacteria isolated from termite digestive tract, Bacillus licheniformis, Ochrobactrum intermedium, and Microbacterium paludicola, on in vitro gas production(IVGP), fermentation parameters, nutrient disappearance, microbial populations, and hydrolytic enzyme activities with fibrous wheat straw(WS) and date leaf(DL) as incubation substrate. Inoculation of RF with either of three termite bacteria increased(P<0.05) ammonia-N concentration compared with the control group(free of termite gut bacteria). Termite bacteria inoculation had no effect(P>0.05) on gas production characteristics, dry matter, organic matter and neutral detergent fiber disappearance, pH, and concentration and composition of volatile fatty acids. Population of proteolytic bacteria and protozoa, but not cellulolytic bacteria, were increased(P<0.05) when RF was inoculated with termite bacteria with both WS and DL substrates. Inoculation of RF with termite bacteria increased protease activity, while activities of carboxymethyl-cellulase, microcrystalline-cellulase, α-amylase and filter paper degrading activity remained unchanged(P>0.05). Overall, the results of this study indicated that transferring lignocellulose-degrading bacteria, isolated from digestive tract of termite, to rumen liquid increased protozoa and proteolytic bacteria population and consequently increased protease activity and ammonia-N concentration in vitro, however, no effect on fermentation and fiber degradation parameters were detected. These results suggest that the termite bacteria might be rapidly lysed by the rumen microbes before beneficial effects on the rumen fermentation process could occur. 展开更多
关键词 ENZYME activity gas production lignocellulose-degrading BACTERIA MICROBIAL population TERMITE BACTERIA
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Long-time precipitation reduction and nitrogen deposition increase alter soil nitrogen dynamic by influencing soil bacterial communities and functional groups 认领
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作者 Guoyong YAN Yajuan XING +3 位作者 Shijie HAN Junhui ZHANG Qinggui WANG Changcheng MU 《土壤圈:英文版》 SCIE CAS CSCD 2020年第3期363-377,共15页
The effects of precipitation reduction and nitrogen deposition increase on soil bacterial communities and functions impact soil nitrogen cycling. Seasonal changes could modify the effects of precipitation reduction an... The effects of precipitation reduction and nitrogen deposition increase on soil bacterial communities and functions impact soil nitrogen cycling. Seasonal changes could modify the effects of precipitation reduction and nitrogen deposition increase on bacterial communities and functions by changing soil environments and properties. Understanding soil microbial communities and the seasonal response of functions to precipitation reduction and nitrogen deposition increase may be important for the accurate prediction of changes in the soil nitrogen dynamics. Thus, a long-term field simulation experiment of nitrogen deposition increase and throughfall exclusion was established to investigate soil bacterial communities’ response to nitrogen deposition increase and/or precipitation reduction, with no nitrogen deposition increase and no precipation reduction as a control, in a temperate forest. We examined soil bacterial communities(Illumina sequencing) under different treatments during the winter, freezing-thawing cycle periods(FTCs), and growing season. The bacterial functional groups were predicted by the FAPROTAX database. The results showed that nitrogen deposition increase, precipitation reduction, the combined effect of nitrogen deposition increase and precipitation reduction, and seasonal changes significantly altered the soil bacterial community composition.Interestingly, by combining the result of a previous study in which nitrogen deposition increase increased the nitrous oxide flux in the same experimental system, the loss of soil nitrogen was increased by the decrease in denitrification and increase of nitrification bacteria under nitrogen deposition increase,while ammonification bacteria significantly increased and N-fixing bacteria significantly decreased with precipitation reduction compared to the control. In relation to seasonal changes, the aromatic-degrading, cellulolytic, and ureolytic bacteria were lowest during FTCs, which indicated that FTCs might inhibit biodegradation. Nitrification and nitrite 展开更多
关键词 copiotrophic bacteria DENITRIFICATION multidimensional effect NITRIFICATION oligotrophic bacteria seasonal changes soil acidification water stress
浓香型白酒在酿造中的功能菌研究进展 认领
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作者 陈继良 《酿酒》 CAS 2020年第2期15-18,共4页
浓香型白酒是中国传统典型的白酒香型之一,具有“醇香浓郁、甘冽清爽、回味悠久”的特点,一直以来深受大众的喜爱。总结归纳了浓香型白酒在酿造中的四大功能菌的特性:细菌、酵母、霉菌与放线菌,以及利用功能菌来提升酒体品质的两大应用... 浓香型白酒是中国传统典型的白酒香型之一,具有“醇香浓郁、甘冽清爽、回味悠久”的特点,一直以来深受大众的喜爱。总结归纳了浓香型白酒在酿造中的四大功能菌的特性:细菌、酵母、霉菌与放线菌,以及利用功能菌来提升酒体品质的两大应用方式:将功能菌加入到入窖前的酒醅中与利用功能菌改善反复使用的人工窖泥。从四种主要的功能菌的功能特性研究及在浓香型白酒酿造中的应用两方面进行总结,旨在为更好地将功能菌在浓香型白酒中应用提供参考。 展开更多
关键词 细菌 酵母 霉菌 放线菌 功能菌应用
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Bacteriology and Antibiotic Sensibility Associated with Extracted Carious Teeth: A Cross Sectional Study at Komfo Anokye Teaching Hospital, Kumasi, Ghana 认领
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作者 Ama Agyeibea Amuasi Alexander Oti Acheampong +4 位作者 Collins Kokuro Alex Ofori Kpedekpo Yayra Joseph Abu-Sakyi Francis Adu-Ababio 《口腔学期刊(英文)》 2020年第5期87-96,共10页
Background: Many oral bacterial species forming the normal flora present as a biofilm in the oral cavity. Dental caries results when there is an imbalance of pathogenic bacteria within these biofilms. Aim: This study ... Background: Many oral bacterial species forming the normal flora present as a biofilm in the oral cavity. Dental caries results when there is an imbalance of pathogenic bacteria within these biofilms. Aim: This study sought to isolate and identify the bacterial species associated with extracted carious teeth and their susceptibility pattern towards commonly employed antimicrobial agents used at the Komfo Anokye Teaching Hospital (KATH). Methodology: A descriptive cross-sectional study carried out on thirty-three extracted carious teeth samples collected by convenient sampling from patients attending the Oral Health Directorate-KATH. All samples were collected from the 11th of March 2019 to the 6th of April 2019. Data was collected using 5 ml peptone water and a case study form. Analysis was done using SPSS version 25 and Microsoft Excel version 10. Results: Twenty (61%) samples were obtained from female patients and thirteen samples (39%) from male patients. Streptococcus spp had the highest occurrence (32.25%) with the least isolated being Pseudomonas and E. coli spp (6.45%). Antibiotic susceptibility test revealed Pseudomonas spp was resistant to all the eight antibiotics used in this study. All bacterial isolates were resistant to Cefuroxime and penicillin except Staphylococcus and Streptococcus spp. Conclusion: The commonest isolates associated with dental caries in KATH were Streptococcus, Bacillus and Staphylococcus spp. In this study most of the isolated species were resistant to common antibiotics employed in the Oral Health Directorate in KATH (amoxicillin/clavulanic, ampicillin and penicillin). From the current study the most effective antibiotic observed was meropenem (23%) with penicillin (3%) being least effective in treating infections of caries. 展开更多
关键词 CARIES BACTERIA Teeth Antibiotic RESISTANCE
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农村小管径重力流灰水管道中生物膜细菌群落的特征 认领
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作者 李文凯 郑天龙 刘俊新 《环境工程学报》 CAS CSCD 北大核心 2020年第3期691-700,共10页
为探究农村小管径重力流灰水管道系统生物膜的细菌群落结构特征,建立了一套模拟真实农村环境条件下水量变化且具有3组坡度参数(5‰,10‰,15‰)的小管径灰水管道实验设备,利用Illumina HiSeq高通量测序技术,分析了连续运行60 d后的管道... 为探究农村小管径重力流灰水管道系统生物膜的细菌群落结构特征,建立了一套模拟真实农村环境条件下水量变化且具有3组坡度参数(5‰,10‰,15‰)的小管径灰水管道实验设备,利用Illumina HiSeq高通量测序技术,分析了连续运行60 d后的管道生物膜的细菌群落特征。结果表明:Proteobacteria、Actinobacteria和Bacteroidetes为优势菌门,优势菌属为Paenarthrobacte、Ensifer和Spingopyxis,坡度变化会显著影响生物膜细菌群落组成;小管径重力流灰水管道生物膜中存在一定丰度的反硝化细菌和硝化细菌,具有生物脱氮功能。通过PICRUSt功能预测发现,高坡度(15‰)的灰水管道具有更高的硝化和反硝化基因丰度。进一步分析可知,小管径灰水管道采用高敷设坡度的设计方案可能具有更强的生物脱氮能力。 展开更多
关键词 小管径重力流管道 灰水 生物膜 细菌 功能菌 功能基因预测
Identification and Characterization of Bacterial Community Associated with the Chewed Feeding Waste of Red Palm Weevil in Infested Date Palm Trees 认领
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作者 AbdulAziz M. A. Mohamed Muhammad Farooq Malabika Roy Pathak 《生命科学与技术进展(英文)》 2020年第3期80-93,共14页
Red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), is considered one of the most damaging insect pests of date palms in the Kingdom of Bahrain. Large scale infestation of RPW to da... Red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), is considered one of the most damaging insect pests of date palms in the Kingdom of Bahrain. Large scale infestation of RPW to date palm trees leads to excessive feeding activity of the RPW larvae, which is carried out by microorganisms present within RPW and producing a wet fermenting material inside the trunk. Culture dependent-bacteria were isolated from feeding waste and identified by the sequencing of the 16S rRNA gene using 8F and 1492R universal primers. Among the culture-dependent isolated bacteria, 80% were identified by comparing 16S rRNA gene sequence in NCBI database, using BLAST program in GenBank. 85% of the identified bacteria were Gram-positive while the rest of them were Gram-negative. A high abundance of bacteria were from the Bacillaceae family and sixteen different species of Bacillus were identified in comparison with NCBI GenBank. The 16S rRNA gene sequences of identified bacterial strains have been submitted to GenBank. The phylogenetic relationship was studied using 16S rRNA gene sequences, the Gram-negative bacteria came in one clade while Gram-positive different Bacillus sp. and strains showed evolutionary closeness to each other and accordingly, they came in one major clade under three different sub-clades in the phylogenetic tree. The findings of new Bacillus strains in the natural habitat of the date plam trees in the Kingdom of Bahrain, pledge a vast area of research on RPW bio-control research arena. 展开更多
关键词 Red PALM WEEVIL (RPW) Bacteria DATE PALM FEEDING WASTE 16S RRNA
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Antibacterial Activity of Essential Oil from <i>Citrus aurantifolia</i>(Christm.) Swingle Peels against Multidrug-Resistant Bacterial Isolates 认领
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作者 N. Torimiro B. R. Adegun +1 位作者 O. E. Abioye R. K. Omole 《微生物学(英文)》 2020年第5期214-223,共10页
The study investigated the antibacterial activity of essential oil from the peel of Citrus aurantifolia against eleven multidrug-resistant (MDR) bacterial isolates of clinical origin. The Kirby-Bauer disc diffusion me... The study investigated the antibacterial activity of essential oil from the peel of Citrus aurantifolia against eleven multidrug-resistant (MDR) bacterial isolates of clinical origin. The Kirby-Bauer disc diffusion method was used to determine the antibiotic resistance profile of the isolates. Essential oil (EO) from the peels of lime purchased at a market in Ile-Ife was extracted by the hydro-distillation method, while the sensitivity of the isolates to EO was done via agar well diffusion method. The minimum inhibitory and minimum bactericidal concentrations (MIC and MBC) of the EO against the tested isolates were determined following standard methods. All the tested isolates exhibited multidrug resistance (MDR) characteristics. The multiple antibiotics resistant indexes (MARI%) for Gram-positive bacterial isolates ranged between 70% and 100% while that of Gram-negative was 100%. The yield of EO was 1% and the EO demonstrated activities at 25%, 50% and 100% v/v against the MDR bacterial isolates. The activity of EO was mostly not significantly different at the same concentration for all the isolates, and at different concentrations for each of the isolates. The MIC range for Gram-negative and Gram-positive isolates was between 0.195% to 3.125% v/v and 0.39% to 3.125% respectively while the range was between 1.563% to 3.125% and 0.781% to 6.250% v/v for MBC respectively. The study showed that EO from the peel of lime fruits demonstrated excellent in vitro antibacterial activity against MDR bacterial isolates. This potential can be further explored as an alternative for the treatment and management of infections caused by MDR bacterial isolates. 展开更多
关键词 CITRUS aurantifolia Essential Oil BACTERIA ANTIBACTERIAL Resistance
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Prime Enzymatic Exocellular Background of <i>Lysinibacillus louembei</i> 认领
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作者 Mo?se Doria Kaya-Ongoto Christian Aimé Kayath +4 位作者 Alain Brice Vouidibio Mbozo Gyna Mobandolaka Mitoko Sandra Paola Elenga Wilson Duchel Jeanedvi Kinouani Kinavouidi Etienne Nguimbi 《微生物学(英文)》 2020年第3期95-109,共15页
Many high-reading journals reject several studies based on the basic aspects of microbiology by forgetting that this could open doors and windows of great scientific discoveries. A new spore-forming bacteria species c... Many high-reading journals reject several studies based on the basic aspects of microbiology by forgetting that this could open doors and windows of great scientific discoveries. A new spore-forming bacteria species called Lysinibacillus louembei has been previously discovered in our research unit. This new study aims to assess a real enzymatic machine produced with such bacteria. Using agarose mixed with half skimmed milk, LB medium supplemented with tween 20, Olive oil, egg yolk, cellulose, casein, pectin and starch, we showed that L. louembei has lipolytic, proteolytic (2.8 cm ± 0.1), cellulolytic, amylolytic pectinolytic activities, with percentage ranging from 30% to 80%. This species is able to secrete lipase, thermostable protease up to 60°C. Cellulase, pectinase and amylase are secreted with more stability between 30°C and 50°C with an optimum at 45°C. The effect of pH was determined after 24 h of incubation at 37°C and 50°C. The proteolytic activity is stable at pH 8 at 50°C. In addition to this first enzymatic landscape, L. louembei is able to degrade and/or tolerate gasoline and/or diesel fuel hydrocarbons in 36 hours. In this work, we also showed that L. louembei can produce biosurfactant in the presence of gasoline and SAE140 with the E24 up to 50%. 展开更多
关键词 Lysinibacillus louembei PRIME ENZYMATIC Exocellular BACTERIA
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COVID-19 Coronavirus: Is Infection along with <i>Mycoplasma</i>or Other Bacteria Linked to Progression to a Lethal Outcome? 认领
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作者 Garth L. Nicolson Gonzalo Ferreira de Mattos 《临床医学国际期刊(英文)》 2020年第5期282-302,共21页
Most patients with COVID-19 disease caused by the SARS-CoV-2 virus recover from this infection, but a significant fraction progress to a fatal outcome. As with some other RNA viruses, co-infection or activation of lat... Most patients with COVID-19 disease caused by the SARS-CoV-2 virus recover from this infection, but a significant fraction progress to a fatal outcome. As with some other RNA viruses, co-infection or activation of latent bacterial infections along with pre-existing health conditions in COVID-19 disease may be important in determining a fatal disease course. Mycoplasma spp. (M. pneumonaie, M. fermentans, etc.) have been routinely found as co-infections in a wide number of clinical conditions, and in some cases this has progressed to a fatal disease. Although preliminary, Mycoplasma pneumoniae has been identified in COVID-19 disease, and the severity of some signs and symptoms in progressive COVID-19 patients could be due, in part, to Mycoplasma or other bacterial infections. Moreover, the presence of pathogenic Mycoplasma species or other pathogenic bacteria in COVID-19 disease may confer a perfect storm of cytokine and hemodynamic dysfunction, autoimmune activation, mitochondrial dysfunction and other complications that together cannot be easily corrected in patients with pre-existing health conditions. The positive responses of only some COVID-19 patients to antibiotic and anti-malaria therapy could have been the result of suppression of Mycoplasma species and other bacterial co-infections in subsets of patients. Thus it may be useful to use molecular tests to determine the presence of pathogenic Mycoplasma species and other pathogenic bacteria that are commonly found in atypical pneumonia in all hospitalized COVID-19 patients, and when positive results are obtained, these patients should treated accordingly in order to improve clinical responses and patient outcomes. 展开更多
关键词 Pathogenic MYCOPLASMA SARS-CoV-2 VIRUS COVID-19 Disease Acute Respiratory Distress Syndrome Co-Infection Pneumonia LETHAL INFECTION Mitochondria Cytokines Anti-Microbial THERAPY Antibiotics Anti-Malarial THERAPY VIRUS BACTERIA
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循环水系统结合鱼菜、紫外处理对镜鲤生长及水质的影响 认领
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作者 罗小龙 Abdessan Rauan +2 位作者 邢君霞 李汉东 吉红 《淡水渔业》 CSCD 北大核心 2020年第2期18-25,共8页
为探索绿色环保的循环水养殖模式,设计循环水鱼菜共生系统(鱼菜组)、紫外灯鱼菜共生系统(鱼菜紫外灯组)及循环水养殖系统(循环水组),比较三种不同处理方式对镜鲤(Cyprinuscarpio var.specularis)、叶用莴苣(Lactuca sativa var.ramosa)... 为探索绿色环保的循环水养殖模式,设计循环水鱼菜共生系统(鱼菜组)、紫外灯鱼菜共生系统(鱼菜紫外灯组)及循环水养殖系统(循环水组),比较三种不同处理方式对镜鲤(Cyprinuscarpio var.specularis)、叶用莴苣(Lactuca sativa var.ramosa)生长和养殖水质的影响。结果显示,鱼菜组、鱼菜紫外灯组处理对镜鲤的生长无显著影响,但会显著影响镜鲤形态学指标,鱼菜组镜鲤肠体比显著低于循环水组。体成分方面,鱼菜组全鱼粗蛋白、粗脂肪显著高于循环水组,鱼菜组肝脏粗蛋白显著低于循环水组。鱼菜紫外灯组的细菌总数显著低于鱼菜组。水质方面,鱼菜组、鱼菜紫外灯组可显著降低系统中氨氮、硝酸盐氮及总磷总氮含量,鱼菜紫外灯组硝酸盐氮、总磷及总氮含量显著高于鱼菜组。综上所述,循环水系统耦合水培蔬菜单元可改善系统水质,改善鱼体成分,并且结合紫外灯处理可降低水体细菌总数。 展开更多
关键词 鱼菜共生 循环水系统 紫外灯 镜鲤(Cyprinuscarpio var.specularis) 细菌 水质
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油橄榄叶提取物的抑菌活性研究 认领
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作者 孔维宝 杨树玲 +3 位作者 霍焕燃 景洋 张爱梅 牛世全 《中国油脂》 CAS CSCD 北大核心 2020年第2期95-100,共6页
以牛津杯扩散法考察油橄榄叶提取物(OLE)对大肠杆菌、金黄色葡萄球菌等8种致病菌的抑菌活性,用稀释法分析OLE对8种细菌生长的影响,并探究最低抑菌质量浓度(MIC)和最低杀菌质量浓度(MBC)。结果表明:以盐酸小檗碱作为对照,OLE对蜡状芽孢... 以牛津杯扩散法考察油橄榄叶提取物(OLE)对大肠杆菌、金黄色葡萄球菌等8种致病菌的抑菌活性,用稀释法分析OLE对8种细菌生长的影响,并探究最低抑菌质量浓度(MIC)和最低杀菌质量浓度(MBC)。结果表明:以盐酸小檗碱作为对照,OLE对蜡状芽孢杆菌、金黄色葡萄球菌、抗四环素大肠杆菌的抑菌作用优于盐酸小檗碱;OLE对表皮葡萄球菌、金黄色葡萄球菌、大肠杆菌的抑菌作用较强(MIC 1 mg/mL,MBC 2 mg/mL)。20 mg/mL的OLE对大肠杆菌的抑制作用最强,为极度敏感(大肠杆菌的d=(25.07±3.02)mm,抗四环素大肠杆菌的d=(24.89±1.58)mm);葡萄球菌次之(表皮葡萄球菌的d=(20.11±1.02)mm,金黄色葡萄球菌的d=(21.35±2.06)mm,金黄色葡萄球菌(SH7)d=(20.01±1.21)mm);而芽孢杆菌处于中度敏感状态。OLE除对铜绿假单胞菌的对数生长期无明显影响外,对其余7种细菌的对数生长期均有延缓作用。OLE具有较强的抑菌活性,可作为一种绿色安全的植物源抑菌制剂。 展开更多
关键词 油橄榄叶 提取物 抑菌活性 细菌
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16S rRNA基因高变区V4和V3-V4及测序深度对油藏细菌菌群分析的影响 认领
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作者 刘明艳 马嘉晗 +3 位作者 李瑜 刘文霞 秦鸿娟 高配科 《微生物学通报》 CAS CSCD 北大核心 2020年第2期440-449,共10页
【背景】16S rRNA基因测序是当前研究微生物群落组成及其分布的重要手段。【目的】揭示16S rRNA基因高变区V4(515-806)和V3-V4(338-806)及测序深度(1-2万条和10万条)对油藏微生物细菌群落组成和多样性分析的影响。【方法】所用油水样细... 【背景】16S rRNA基因测序是当前研究微生物群落组成及其分布的重要手段。【目的】揭示16S rRNA基因高变区V4(515-806)和V3-V4(338-806)及测序深度(1-2万条和10万条)对油藏微生物细菌群落组成和多样性分析的影响。【方法】所用油水样细菌16SrRNA基因拷贝数为(6.51±0.56)×108/L,16SrRNA基因V4区测序使用IlluminaMiSeqPE250测序平台,V3-V4区测序使用MiSeqPE300测序平台。【结果】测序深度达到1-2万条时,V4和V3-V4区测序文库覆盖率均达到99.6%以上,且具有较好的可重复性;V4区测序深度为1-2万和10万时,菌群α多样性指数受测序深度影响不显著;与V4区测序相比,同样测序深度(1-2万)下,V3-V4区测序获得的菌群α多样性指数有所降低。V4测序1-2万与10万获得的菌群中几乎未出现显著性差异微生物类群;同样测序深度(1-2万)下,V4与V3-V4测序相比,优势微生物类群Epsilonproteobacteria(51.37%:64.23%)和Deltaproteobacteria(17.96%:11.40%)相对丰度表现出显著差异。【结论】测序深度达到一定水平,增加测序深度会一定程度上影响菌群α多样性指数,对菌群β多样性分析的影响十分有限;同一测序深度下,V4区与V3-V4区测序获得的细菌菌群α多样性指数明显不同,部分优势微生物类群的相对丰度值之间具有显著性差异。鉴于测序读长的提升和测序成本降低,与V4区测序相比,V3-V4区测序在更低的测序深度下文库覆盖率更高,可提供更多用于反映物种亲缘关系的16S rRNA碱基信息,本文认为V3-V4区测序可作为当下菌群分析的首选区域。 展开更多
关键词 油藏 细菌 16S rRNA V4 V3-V4 MiSeq测序
脓毒症患者炎症因子与内毒素变化和细菌类型及病情的关系研究 认领
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作者 彭婷婷 刘云红 轩凯 《中华医院感染学杂志》 CAS CSCD 北大核心 2020年第4期487-491,共5页
目的探讨细菌血流感染致脓毒症患者血清降钙素原(PCT)、超敏C-反应蛋白(hs-CRP)、内毒素的变化与细菌感染类型及患者病情的关系。方法选取2015年2月-2018年10月河南省人民医院确诊的脓毒症患者80例作为病例组、同期健康体检志愿者80名... 目的探讨细菌血流感染致脓毒症患者血清降钙素原(PCT)、超敏C-反应蛋白(hs-CRP)、内毒素的变化与细菌感染类型及患者病情的关系。方法选取2015年2月-2018年10月河南省人民医院确诊的脓毒症患者80例作为病例组、同期健康体检志愿者80名作为对照组,对比两组研究对象的血清PCT、hs-CRP、内毒素水平,并按照病原菌类型分层分析病例组患者的血清PCT、hs-CRP、内毒素水平,采用线性相关分析法分析血清PCT、hs-CRP、内毒素与急性生理与慢性健康评分(APACHEⅡ)、序贯器官衰竭评分(SOFA)的关系。结果病例组患者的血清PCT、hs-CRP及内毒素分别为(1.22±0.40)μg/L、(86.14±24.71)mg/L及(11.39±4.39)ng/L高于对照组(P<0.05);革兰阳性菌感染的脓毒症患者血清PCT、hs-CRP及内毒素分别为(0.75±0.32)μg/L、(65.40±22.33)mg/L及(6.77±3.95)ng/L低于革兰阴性菌感染的脓毒症患者(P<0.05);革兰阳性菌感染的脓毒症患者APACHEⅡ评分、SOFA评分分别为(9.44±3.02)分、(26.81±4.20)分低于革兰阴性菌感染的脓毒症患者;脓毒症患者APACHEⅡ评分、SOFA评分与患者的血清PCT、hs-CRP及内毒素水平均呈正相关(P<0.001)。结论革兰阴性菌感染导致的脓毒症患者血清PCT、hs-CRP、内毒素水平升高更显著,并且与患者病情严重程度的关系更加显著。 展开更多
关键词 细菌 血流感染 脓毒症 降钙素原 超敏C-反应蛋白 内毒素
冷冻原肠中细菌基因组DNA提取方法的建立 认领
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作者 宋鸿雁 仇保丰 +4 位作者 高雪梅 刘春 刘文斌 朱顺星 邵义祥 《中国动物检疫》 CAS 2020年第2期87-93,共7页
为建立冷冻原肠中细菌基因组DNA的直接提取法,采用震荡洗脱、金属网过滤和梯度离心相结合的方法,对2份冷冻原肠样品进行前处理;对经前处理后的原肠样品,采用酚/氯仿法提取细菌基因组DNA,然后进行琼脂糖电泳和OD260/OD280比值测定;以细... 为建立冷冻原肠中细菌基因组DNA的直接提取法,采用震荡洗脱、金属网过滤和梯度离心相结合的方法,对2份冷冻原肠样品进行前处理;对经前处理后的原肠样品,采用酚/氯仿法提取细菌基因组DNA,然后进行琼脂糖电泳和OD260/OD280比值测定;以细菌基因组DNA为模板,用PCR技术扩增细菌16S rDNA并构建克隆文库,并从2个文库中各随机挑取3个菌落进行16S rDNA的PCR鉴定和DNA测序。结果显示:样品提取的DNA浓度、纯度较高,OD260/OD280比值介于1.8~2.0;挑取的6个菌落中,1个为阴性,剩余5个为阳性,为肠球菌属(Enterococcus)和魏斯氏菌属(Weissella)的5种细菌。结果表明,本研究提取的原肠细菌基因组DNA质量较好,可用于非培养法研究冷冻原肠中细菌的多样性。本研究解决了因缺乏原肠细菌基因组DNA提取方法,无法进一步应用现代分子生物学方法研究冷冻原肠细菌的多样性、菌群组成结构和动态变化等难题。 展开更多
关键词 冷冻原肠 细菌 细菌基因组DNA 提取方法
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氢呼气试验在老年性便秘患者小肠细菌生长状况分析中的应用 认领
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作者 张晓南 徐丽姝 +2 位作者 邓罡 张凯军 陈晋 《中华老年医学杂志》 CAS CSCD 北大核心 2020年第6期693-694,共2页
老年慢性便秘患者多伴有小肠动力障碍,小肠细菌过度生长(SIBO)发生率高。采用氢呼气试验(HBT)可对比老年便秘患者和非便秘患者的小肠细菌生长和分布情况、小肠蠕动速度、回盲瓣功能等,分析老年性便秘SIBO的成因及程度。本结果显示老年... 老年慢性便秘患者多伴有小肠动力障碍,小肠细菌过度生长(SIBO)发生率高。采用氢呼气试验(HBT)可对比老年便秘患者和非便秘患者的小肠细菌生长和分布情况、小肠蠕动速度、回盲瓣功能等,分析老年性便秘SIBO的成因及程度。本结果显示老年性便秘患者出现SIBO的概率与无便秘的老年人差异无统计学意义,但老年性便秘的SIBO发生可能与回肠反流相关,且出现在小肠全程。 展开更多
关键词 便秘 小肠 细菌 呼气
细菌生物膜与皮肤病相关性研究进展 认领
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作者 韩阳 李晓东 《中国麻风皮肤病杂志》 2020年第7期445-448,共4页
细菌生物膜在皮肤病发病机制中的作用受到越来越多的关注。研究发现,在痤疮、特应性皮炎、化脓性汗腺炎、脓疱疮和皮肤创伤感染等皮损部位均可检测到细菌生物膜。不同皮肤疾病中细菌生物膜不同,致病机制也不同。本文综述了细菌生物膜在... 细菌生物膜在皮肤病发病机制中的作用受到越来越多的关注。研究发现,在痤疮、特应性皮炎、化脓性汗腺炎、脓疱疮和皮肤创伤感染等皮损部位均可检测到细菌生物膜。不同皮肤疾病中细菌生物膜不同,致病机制也不同。本文综述了细菌生物膜在皮肤病发生发展中的作用。 展开更多
关键词 细菌 生物膜 皮肤疾病
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2016~2018年泌尿外科患者尿路感染病原菌分布及耐药性分析 认领
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作者 陈中举 田磊 +1 位作者 杨为民 刘征 《临床泌尿外科杂志》 2020年第2期103-107,111共6页
目的:对泌尿外科患者尿路感染的病原菌分布及耐药性进行分析,给临床治疗提供依据。方法:收集2016年1月~2018年12月我院泌尿外科患者尿路感染病原菌2597株,使用MALDI-TOF飞行质谱仪进行菌株的鉴定,采用纸片扩散法进行药敏试验,采用WHONET... 目的:对泌尿外科患者尿路感染的病原菌分布及耐药性进行分析,给临床治疗提供依据。方法:收集2016年1月~2018年12月我院泌尿外科患者尿路感染病原菌2597株,使用MALDI-TOF飞行质谱仪进行菌株的鉴定,采用纸片扩散法进行药敏试验,采用WHONET 5.6软件进行耐药率分析,使用SPSS统计软件进行χ~2检验和统计分析。结果:分离革兰阴性菌1860株,革兰阳性菌520株,念珠菌217株,分别占71.6%、20%和8.4%。大肠埃希菌、屎肠球菌、念珠菌属、粪肠球菌和肺炎克雷伯菌排在前5位,分别占总菌株数的46.5%、8.7%、8.4%、7.9%和7.5%。大肠埃希菌和肺炎克雷伯菌的ESBLs发生率分别为59.4%和43.3%。与2016年相比,2018年分离的大肠埃希菌对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、亚胺培南、庆大霉素、妥布霉素和呋喃妥因的耐药率显著降低。肺炎克雷伯菌、铜绿假单胞菌、屎肠球菌和粪肠球菌对各种抗菌药物的耐药率在3年之间未显示出显著性差异。大肠埃希菌及肺炎克雷伯菌对哌拉西林、头孢噻肟、头孢唑啉、头孢吡肟、环丙沙星、左旋氧氟沙星等耐药率多在60%以上。粪肠球菌对环丙沙星和左氧氟沙星的耐药率分别为24.0%和22.4%,屎肠球菌对环丙沙星和左氧氟沙星的耐药率分别为97.7%和96.8%。结论:泌尿外科患者尿路感染的主要病原菌为肠杆菌科细菌中的大肠埃希菌和肺炎克雷伯菌,且产超广谱β内酰胺酶菌株检出率较高。此外,屎肠球菌、粪肠球菌、念珠菌也是常见分离菌。临床医生要密切关注分离菌的变迁及耐药性情况,合理使用抗菌药物。 展开更多
关键词 泌尿外科患者 尿路感染 病原菌 抗菌药物
中药通过调节细菌群体感应系统改善人体健康研究进展 认领
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作者 杨敏 顾雯 +7 位作者 杨柏荣 李凤娇 陶雅婷 张铮洋 张范 李静平 杨兴鑫 俞捷 《中国中药杂志》 CAS CSCD 北大核心 2020年第6期1297-1303,共7页
群体感应(quorum sensing,QS)是近年来微生物学、医学等领域的研究焦点之一。细菌之间的群体感应是指细菌菌群通过感应环境中特定信号分子的浓度而调节群体密度的一种相互作用机制。细菌的群体感应系统通过影响细菌生长、增殖、生物膜... 群体感应(quorum sensing,QS)是近年来微生物学、医学等领域的研究焦点之一。细菌之间的群体感应是指细菌菌群通过感应环境中特定信号分子的浓度而调节群体密度的一种相互作用机制。细菌的群体感应系统通过影响细菌生长、增殖、生物膜形成、毒力功能、抗生素合成等生物学功能,最终实现其对环境变化的适应。目前,在中药中发现越来越多调节群体感应的活性物质,中药及其活性成分可通过调节细菌群体感应系统,促进有益菌的生长,抑制致病菌的增殖,最终实现治疗疾病的目的,体现了中药药效多途径多靶点的特点。该文首先介绍了细菌之间的群体感应信号分子种类及调节机制,在此基础上对人体健康相关的细菌群体感应进行了总结,进而综述了中药对细菌群体感应系统的调节作用,最后指出中药通过细菌群体感应系统改善人体健康的物质基础及作用机制仍不清楚,未来的研究热点将集中在中药群体感应活性物质,群体感应关键节点及相关靶点等方面,以期为有关疾病的治疗提供参考。 展开更多
关键词 中药 细菌 群体感应 健康
斑马鱼肿瘤坏死因子(tnfα)及其受体(tnfrsf1a)应答细菌和病毒感染的表达 认领
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作者 田佳音 陈康勇 +3 位作者 张畅 宋云杰 高谦 邹钧 《上海海洋大学学报》 CAS CSCD 北大核心 2020年第2期171-179,共9页
肿瘤坏死因子(tumor necrosis factor,Tnf)作为重要的炎症因子,在抵抗细菌和病毒感染以及清除被感染的细胞等方面发挥着重要的作用。对斑马鱼进行腹腔注射免疫刺激物、细菌和病毒病原,并采用荧光定量PCR技术分析tnfα及其受体[tnf recep... 肿瘤坏死因子(tumor necrosis factor,Tnf)作为重要的炎症因子,在抵抗细菌和病毒感染以及清除被感染的细胞等方面发挥着重要的作用。对斑马鱼进行腹腔注射免疫刺激物、细菌和病毒病原,并采用荧光定量PCR技术分析tnfα及其受体[tnf receptor superfamily(tnfrsf)member 1a]在肾脏和脾脏中的表达。实验结果显示:tnfα和tnfrsf1a在斑马鱼各组织中均有常量表达。脂多糖(lipopolysaccharide,LPS)和聚肌苷酸-聚胞苷酸[polyinosinic acid-polycytidylic acid,poly(I:C)]能够调控肾脏和脾脏中tnfα和tnfrsf1a的表达。腹腔注射嗜水气单胞菌(Aeromonas hydrophila)感染斑马鱼后,tnfα在脾脏(48 h和72 h)和肾脏(72 h)中表达显著升高;tnfrsf1a在脾脏(48 h)表达水平也有显著上调。在注射迟缓爱德华氏菌(Edwardasiella tarda)的斑马鱼中,肾脏的tnfα表达显著增加,但在脾脏的表达则完全被抑制;tnfrsf1a基因在脾脏和肾脏(6 h和72 h)有明显上调。鲤春病毒血症病毒(spring viraemia of carp virus,SVCV)感染斑马鱼后,tnfα和tnfrsf1a在感染早期表达量有显著升高;而且在感染1~7 d中,肾脏的tnfrsf1a始终维持高水平诱导表达。实验结果表明:tnfα和tnfrsf1a在鱼类抵抗细菌和病毒感染过程中发挥重要作用。 展开更多
关键词 斑马鱼 肿瘤坏死因子 肿瘤坏死因子受体超级家族成员1a 表达 细菌 病毒
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