多黏菌素B治疗泛耐药鲍曼不动杆菌感染的临床分析

目的探讨以多黏菌素B为基础的抗感染方案治疗泛耐药鲍曼不动杆菌(简称“AB”)感染的临床用法及疗效。方法回顾性分析2018年1月-2019年5月收治的泛耐药AB感染者60例的临床资料。分别根据多黏菌素B的用药时间及联合药物的不同进行分组,比较各组间的细菌清除率和治疗总有效率。结果(1)60例患者均予多黏菌素B为基础的抗感染方案,细菌清除率达58.3%,总治疗有效率达51.6%;(2)用药时间≥7 d细菌清除率及治疗总有效率均高于用药时间<7 d(P<0.05);(3)多黏菌素B联合替加环素组、多黏菌素B联合头孢哌酮-舒巴坦组及多黏菌素B联合米诺环素组3组在细菌清除率及治疗总有效率比较,差别均无统计学意义(P>0.05)。结论足量的给药疗程能提高多黏菌素B治疗泛耐药AB的细菌清除率及临床治疗有效率。尽管菌株对碳青霉烯类、头孢哌酮舒巴坦或米诺环素耐药,但上述药物仍能作为在泛耐药AB感染治疗上多黏菌素B联合用药的选择。

The Effect of Nivalenol on Metabolism of Cultured Chondrocytes and the Protection of Selenium

Objective: To investigate the possible effect of nivalenol on metabolism ofthe cultured chondrocytes and the protection of selenium. Methods: The quantitative analyses ofmetabolism in single- layer cultured chondrocytes were performed by biocliemical means and theimpairment of DNA was observed by both of the single cell microgel electrophoresis assay and theagarose gel electrophoresis assay. Results: In the media containing different concentrations ofnivalenol (0. 000 5-0. 020 0 mg/L), the amounts of DNA and proteoglycan in matrix of thechondrocytes were decreased. The syn-thesis of protein was reduced and the impairment of DNAdeteriorated with the increase of the concentrations of nivalenol in tlte given dose. When seleniumwas added into the media, the impairment by nivalenol was decreased. In the media containingdifferent concentrations of nivalenol, however, the lipid peroxidation of the chondrocytes was notaffected by nivalenol, yet the amount of lipid peroxides significantly declined. Conclusion:Nivalenol may evidently cause impairment of the chondrocytes when its concentrations are in thepresent experimental range. Selenium can protect cultured cliondrocytes, but cannot prevent theirDNA from being impaired.

Observation and simulation of 2-methylisoborneol in the Qingcaosha Reservoir,Changjiang estuary

2-Methylisoborneol(2-MIB) is a cyanobacterial metabolite that is responsible for many taste and odor(T&O) complaints related to the aesthetics of drinking water and poses a problem for water authorities because it is recalcitrant during conventional water treatment. A numerical model was developed to simulate 2-MIB in the Qingcaosha Reservoir, an estuarine drinking water resource in the Changjiang estuary with known 2-MIB episodes. The objective of this study was to numerically simulate the generation and release processes of 2-MIB in the reservoir and to provide useful information for better management of drinking water resources experiencing T&O problems caused by cyanobacteria. The simulation results from 2009 to 2013 showed that the simulated 2-MIB concentrations corresponded well to the observational data. 2-MIB was released mainly during periods of low dissolved oxygen(DO) levels with an adequate potential sediment source. The temporal and spatial variations in nutrients, chlorophyll-a(Chl-a), Cyanophyta and 2-MIB were presented and analyzed during 2009 to 2013. According to the study results, high-concentration areas and peak levels of 2-MIB can be controlled by inhibiting algal growth and increasing oxygen levels in the water, which can be achieved via adequate water exchange and oxygen exposure in the reservoir, respectively.

Effects of Biological Bacterial Fertilizer on Carbon Metabolism Characteristics of Rhizosphere Soil Bacteria in Rice

The effects of biological bacterial fertilizer and chemical fertilizer on carbon metabolism characteristics of rhizosphere soil bacteria in rice were studied through a plot experiment.The results showed that the number and Mcintosh index of bacteria in rice rhizosphere soil increased significantly with the application of biological bacterial fertilizer.It was found that the AWCD(average well color development)value of the bacteria remarkably increased and the decomposition of carboxylic acids,amines and heterozygotes were accelerated when adding biological bacterial fertilizer at a proper weight percent.All in all,proper addition of biological bacterial fertilizer could increase the number and carbon metabolism of bacteria.The most appropriate application rate was 70%chemical fertilizer nitrogen+30%biological bacterial fertilizer nitrogen for rice production in Northern Jiangsu Province.

Biotransformation of aesculin by human gut bacteria and identification of its metabolites in rat urine

AIM： To observe the biotransformation process of a Chinese compound, aesculin, by human gut bacteria, and to identify its metabolites in rat urine.METHODS： Representative human gut bacteria were collected from 20 healthy volunteers, and then utilized in vitro to biotransform aesculin under anaerobic conditions. At 0, 2, 4, 8, 12, 16, 24, 48 and 72 h postincubation, 10 mL of culture medium was collected. Metabolites of aesculin were extracted 3 × from rat urine with methanol and analyzed by HPLC. For in vivo metabolite analysis, aesculetin （100 mg/kg） was administered to rats via stomach gavage, rat urine was collected from 6 to 48 h post-administration, and metabolite analysis was performed by LC/ESI-MS and MS/MS in the positive and negative modes.RESULTS： Human gut bacteria could completely convert aesculin into aesculetin in vitro. The biotransformation process occurred from 8 to 24 h post-incubation, with its highest activity was seen from 8 to 12 h. The in vitro process was much slower than the in vivo process. In contrast to the in vitro model, six aesculetin metabolites were identified in rat urine, including 6-hydroxy-7-glucocoumarin（M1）, 6-hydroxy-7-sulf-coumarin （M2）, 6, 7-digluco-coumarin （M3）, 6-glc-7-gluco-coumarin （M4）, 6-O-methyl-7-gluco-coumarin （MS） and 6-O-methyl-7- sulf-coumarin （M6）. Of which, M2 and M6 were novel metabolites.CONCLUSION： Aesculin can be transferred into aesculetin by human gut bacteria and is further modified by the host in vivo. The diverse metabolites of aesculin may explain its pleiotropic pharmaceutical effects.

Metabolic and Phylogenetic Profile of Bacterial Community in Guishan Coastal Water(Pearl River Estuary), South China Sea

Characteristics of a microbial community are important as they indicate the status of aquatic ecosystems. In the present study, the metabolic and phylogenetic profile of the bacterioplankton community in Guishan coastal water(Pearl River Estuary), South China Sea, at 12 sites(S1–S12) were explored by community-level physiological profiling(CLPP) with BIOLOG Eco-plate and denaturing gradient gel electrophoresis(DGGE). Our results showed that the core mariculture area(S6, S7 and S8) and the sites associating with human activity and sewage discharge(S11 and S12) had higher microbial metabolic capability and bacterial community diversity than others(S1–5, S9–10). Especially, the diversity index of S11 and S12 calculated from both CLPP and DGGE data(H >3.2) was higher than that of others as sewage discharge may increase water nitrogen and phosphorus nutrient. The bacterial community structure of S6, S8, S11 and S12 was greatly influenced by total phosphorous, salinity and total nitrogen. Based on DGGE fingerprinting, proteobacteria, especially γ- and α-proteobacteria, were found dominant at all sites. In conclusion, the aquaculture area and wharf had high microbial metabolic capability. The structure and composition of bacterial community were closely related to the level of phosphorus, salinity and nitrogen.

Probiotic metabolites from Bacillus coagulans GanedenBC30^(TM) support maturation of antigen-presenting cells in vitro

AIM:To study the effects of probiotic metabolites on maturation stage of antigen-presenting immune cells.METHODS:Ganeden Bacillus coagulans 30(GBC30) bacterial cultures in log phase were used to isolate the secreted metabolite(MET) fraction.A second fraction was made to generate a crude cell-wall-enriched fraction,by centrifugation and lysis,followed by washing.A preparation of MET was subjected to size exclusion centrifugation,generating three fractions:< 3 kDa,3-30 kDa,and 30-200 kDa and activities were tested in comparison to crude MET and cell wall in primary cultures of human peripheral blood mononuclear cell(PBMC) as a source of antigen-presenting mononuclear phagocytes.The maturation status of mononuclear phagocytes was evaluated by staining with monoclonal antibodies towards CD14,CD16,CD80 and CD86 and analyzed by flow cytometry.RESULTS:Treatment of PBMC with MET supported maturation of mononuclear phagocytes toward both macrophage and dendritic cell phenotypes.The biological activity unique to the metabolites included a reduction of CD14+ CD16+ pro-inflammatory cells,and this property was associated with the high molecular weight metabolite fraction.Changes were also seen for the dendritic cell maturation markers CD80 and CD86.On CD14dim cells,an increase in both CD80 and CD86 expression was seen,in contrast to a selective increase in CD86 expression on CD14bright cells.The co-expression of CD80 and CD86 indicates effective antigen presentation to T cells and support of T helper cell differentiation.The selective expression of CD86 in the absence of CD80 points to a role in generating T regulatory cells.CONCLUSION:The data show that a primary mechanism of action of GBC30 metabolites involves support of more mature phenotypes of antigen-presenting cells,important for immunological decision-making.

Effect of the Type of Vitis vinifera Cultivation in the Cenophenoresistome and Metabolic Profiling （CLPP） of Edaphic Bacterial Communities

In the present work, bacterial soil communities of different grapevine exploitation samples are studied in order to elucidate the possible influence of different agrarian management techniques （use of fertilizers, irrigation with river water） may have on the rhizospheric microbiome of Vitis vinifera plants. Therefore, it is postulated the Cenophenoresistome as a novel methodology to evaluate complex communities＇ global resistance against different antibiotics, by using and adjusting a serial of techniques traditionally applied to evaluate a monospecific population＇s resistance against antibiotics （Vitek, ATB and disk diffusion methods）. Likewise, the metabolic profile （CLPP： comunity level physiological profile） of bacterial communities is studied by Biolog ECO. In relation to the functional structure of the bacterial communities, it is observed that the metabolic profile （diversity, kinetics and CLPP） of unexploited soils differs from soils under anthropic influence. It is discussed the causes of resistance in the human clinic antibiotic treatment based on the agrarian management, especially with the contamination transmitted by irrigation water, which could be associated with changes in edaphic communities. The results obtained in the present study through two different approaches （Cenophenoresistome and metabolic profiles） are consistent with each other, suggesting that both methods can be good bioindicators of the state of humankind-altered soils that host natural ecosystems. Likewise, the concept of Cenophenoresistome is proposed as a bioindicator of soil response to alteration processes, as well as a possible predictor of its evolution in edaphic remediation processes.

Simultaneous Removal of Thiophene and Dibenzothiophene by Immobilized Pseudomonas delafieldii R-8 cells

Biodesulfurization （BDS） is a promising technology for deep desulfurization. In this work, Pseudomonas delafieldii R-8 cells are immobilized in calcium alginate beads and used for BDS of transportation fuels. It is found that thiophene and dibenzothiophene （DBT） can be simultaneously metabolized by immobilized R-8 cells. The initial sulfur content in the model oil is 300 mg·kg-1 （thiophene ＂ DI3T= 1 ＂ 1）. After 10 h of treatment, the thiophene concentration is reduced by 40%, while DBT is reduced by 25%. The utilization rate of thiophene is faster than that of DBT. Moreover, the oil/water ratio of alginate immobilized cells is studied to reduce the water volume in desulfurization systems. Long-term recycling of BDS by alginate immobilized cells is carried out with oil/water ratio at 5 ： 1. The immobilized cells are successfully reused over 15 batch cycles. In the last batch, the desulfurization activity remains at least 75% of the first batch.

Effect of Metabolites of Fusarium Solani on Tyrosine Phosphorylation in Cultivated Cells of Solarium Tuberosum

Elicitor-induced phosphorylation of tyrosine residues in proteins of potato was studied. Proteins of crude extract of suspension culture of potato were analyzed by one- and two-dimensional electrophoresis followed by Western blotting with monoclonal antibodies PY20 to phosphotyrosine proteins. One- and two-dimensional electrophoresis revealed l l and 25 tyrosine-phosphorylated proteins, respectively. Glycoprotein increased the phosphorylation level of most of these proteins.

降钙素原和外周血白细胞／血小板单独或联合检测对肝硬化合并细菌感染患者早期诊断中的应用价值研究

目的探讨降钙素原（PCT）和外周血白细胞（WBC）、血小板（PLT）、WBC／PLT单项及联合检测对肝硬化合并细菌感染患者早期诊断的应用价值。方法选取本院2014年3月至2016年3月的128例肝硬化合并细菌感染患者为观察组，选取128例肝硬化未合并细菌感染患者为病例对照组，选取同期健康体检者128例为健康对照组，三组研究对象均进行PCT、WBC、PLT、WBC／PLT单项或联合检测，比较三组间PCT、WBC、PLT、WBC／PLT水平的差异，并对PCT、WBC、PLT、WBC／PLT单项或联合检测的敏感度、特异度、阳性预测值和阴性预测值进行分析。结果3组研究对象血清中的PCT、WBC、PLT、WBC／PLT含量差异有统计学意义（P〈0．05）；PCT、WBC、PLT、WBC／PLT单独检测的敏感度、特异度、阳性预测值和阴性预测值之间差异有统计学意义（P〈0．05）；PCT联合WBC检测、PCT联合PLT检测的敏感度、特异度、阳性预测值和阴性预测值与PCT联合WBC／PLT检测差异有统计学意义（P〈0．05）。结论PCT、WBC、PLT、WBC／PLT可以很好地诊断肝硬化合并细菌感染患者，而且PCT联合WBC／PLT检测更适合肝硬化合并细菌感染的早期诊断。

血清LDH、 CK、 AST及CSF LDH水平检测在成人颅内感染患者中的临床意义

目的 探讨血清乳酸脱氢酶（LDH）、肌酸激酶（CK）、天冬氨酸转氨酶（AST）及脑脊液乳酸脱氢酶（CSF LDH）检测在成人颅内感染患者急性期的变化及其临床意义.方法 收集病毒性脑炎（病脑组）47例,结核性脑膜炎（结脑组）30例和化脓性脑膜炎（化脑组）19例及体检正常者（对照组）39例的血清标本,并收集颅内感染组的腰穿脑脊液.采用贝克曼全自动生化分析仪,以酶速率法测定所有标本的血清AST、LDH、CK以及患者CSF的LDH.结果 （1）颅内感染组血清心肌酶LDH、CK、AST水平均显著高于非感染组（P＜0.01）.（2）根据有无瘫痪、抽搐、失语、昏迷等症状将脑膜炎患者分为障碍组和无障碍组,障碍组血清LDH、AST水平均明显高于无障碍组（P＜0.05）.（3）病脑组血清AST、LDH、CK水平,化脑组血清AST、LDH水平及结脑组血清LDH水平均明显高于对照组（P＜0.01）,结脑组和化脑组CSF LDH活性升高程度较病脑组高（P＜0.01）.（4）直线相关分析颅内感染患者血清LDH与脑脊液LDH无相关（P＞0.05）.结论 （1）成人颅内感染急性期存在明显的血清LDH、CK、AST及CSF LDH的改变,以LDH改变最为明显,在合并有脑功能障碍时LDH、AST改变更明显;（2）检测血清LDH、CK、AST和CSF LDH水平有助于颅内感染早期的鉴别诊断,以及判断病情的严重程度.

Comparative proteome analysis of alkaliphilic Bacillus sp.N16-5 grown on different carbon sources

To determine the impact of carbohydrates on the metabolic pathway in alkaliphiles, proteomes were obtained from cultures containing different carbohydrates and were resolved on two-dimensional gel electrophoresis (2-DE). The proteomes were compared to determine differentially expressed proteins. A novel alkaliphilic bacterium (alkaliphilic Bacillus sp. N16-5 isolated from Wudunur Soda Lake, China) was isolated in media with five different carbon sources (glucose, mannose, galactose, arabinose, and xylose). Comparative proteome analysis identified 61 differentially expressed proteins, which were mainly involved in carbohydrate metabolism, amino acid transport, and metabolism, as well as energy production and conversion. The comparison was based on the draft genome sequence of strain N16-5. The abundance of enzymes involved in central metabolism was significantly changed when exposed to various carbohydrates. Notably, catabolite control protein A (CcpA) was up-regulated under all carbon sources compared with glucose. In addition, pentose exhibited a stronger effect than hexose in CcpA-mediated carbon catabolite repression. These results provided a fundamental understanding of carbohydrate metabolism in alkaliphiles.

INFER OBJECTIVE FUNCTION OF GLYCEROL METABOLISM IN KLEBSIELLA PNEUMONIAE BASING ON BILEVEL PROGRAMMING

Mathematical modelling of cellular metabolism plays an important role in understandingbiological functions and providing identification of targets for biotechnological modification.This paperproposes a nonlinear bilevel programming(NBP)model to infer the objective function of anaerobicglycerol metabolism in Klebsiella Pneumoniae(K.Pneumoniae)for 1,3-propanediol(1,3-PD)production.Based on the Kuhn-Tucker optimality condition of the lower level problem,NBP is transformedinto a nonlinear programming with complementary and slackness conditions.The authors give the existencetheorem of solutions to NBP.An efficient algorithm is proposed to solve NBP and its convergenceis also simply analyzed.Numerical results reveal some interesting conclusions,e.g.,biomass productionis the main force to drive glycerol metabolism,and the objective functions,which are obtained in termof several different groups of flux distributions,are similar.

Identification of poliumoside metabolites in rat plasma, urine, bile, and intestinal bacteria with UPLC/Q-TOF-MS

Poliumoside is representative of phenylethanoid glycosides, which are widely found in many plants. Poliumoside is also regarded as the main active component of Callicarpa kwangtungensis Chun(CK), though its oral bioavailability in rat is extremely low(0.69%) and its in vivo and in vitro metabolism has not yet been systematically investigated. In the present study, an ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry(UPLC/Q-TOF-MS) method was employed to identify the metabolites and investigate the metabolic pathways of poliumoside in rat after oral administration 1.5 g·kg–1 of poliumoside. As a result, a total of 34 metabolites(30 from urine, 17 from plasma, and 4 from bile) and 9 possible metabolic pathways(rearrangment, reduction, hydration, hydrolyzation, dehydration, methylation, hydroxylation, acetylation, and sulfation) were proposed in vivo. The main metabolite, acteoside, was quantified after incubated with rat intestinal bacteria in vitro. In conclusion, the present study systematically explored the metabolites of poliumoside in vivo and in vitro, proposing metabolic pathways that may be significant for further metabolic studies of poliumoside.

Shifts in chemical and microbiological properties belowground of invader Ageratina adenophora along an altitudinal gradient

Tropical mountain ecosystems are usually colonized by numerous invasive plant species and represent an ideal‘natural laboratory’to study the effects of altitude on plant invasion.The aim of this study was to investigate the soil chemical and microbiological properties along an altitudinal gradient on a mountain colonized by the invader Ageratina adenophora.Rhizosphere soil of A.adenophora was collected over an altitudinal gradient(1400–2400 m)in Ailao Shan,China.We determined soil organic carbon(C),nutrient contents,enzyme activities,bacterial community composition as well as C and nitrogen(N)contents of the plant roots.Ecoenzymatic stoichiometric indices were calculated to estimate the relative C,N or P limitations of the microbial community.There was a significant effect of altitude on soil organic C in the rhizosphere,and a turning point in these measured variables was detected at an altitude of 2000 m.At low elevations,the rapid growth of invasive plants depleted the deficient phosphorus(P)in tropical soils,leading to microbial P limitation;at high elevations,microbes invested more energy to obtain C from resistant litter,leading to microbial C limitation.Bacterial beta diversity and soil pH contributed most to the altitudinal differences in ecoenzymatic stoichiometry,and Proteobacteria and Acidobacteria were the dominant bacterial phyla that determined the nutrient uptake status of microorganisms.These results demonstrate how microbial nutrient acquisition belowground of A.adenophora along an altitudinal gradient,which could contribute to further knowledge about the effects of altitude on biological invasion.

Sulfur metabolism by marine heterotrophic bacteria involved in sulfur cycling in the ocean

Sulfur cycling in the biosphere is tightly interwoven with the cycling of carbon and nitrogen,through various biological and geochemical processes.Marine microorganisms,due to their high abundance,diverse metabolic activities,and tremendous adaptation potential,play an essential role in the functioning of global biogeochemical cycles and linking sulfur transformation to the cycling of carbon and nitrogen.Currently many coastal regions are severely stressed by hypoxic or anoxic conditions,leading to the accumulation of toxic sulfide.A number of recent studies have demonstrated that dissimilatory sulfur oxidation by heterotrophic bacteria can protect marine ecosystems from sulfide toxicity.Sulfur-oxidizing bacteria have evolved diverse phylogenetic and metabolic characteristics to fill an array of ecological niches in various marine habitats.Here,we review the recent findings on the microbial communities that are involved in the oxidation of inorganic sulfur compounds and address how the two elements of sulfur and carbon are interlinked and influence the ecology and biogeochemistry in the ocean.Delineating the metabolic enzymes and pathways of sulfur-oxidizing bacteria not only provides an insight into the microbial sulfur metabolism,but also helps us understand the effects of changing environmental conditions on marine sulfur cycling and reinforces the close connection between sulfur and carbon cycling in the ocean.