A Wohlfahrtiimonas chitiniclastica with a novel type of blaVEB–1-carrying plasmid isolated from a zebra in China

BackgroundWohlfahrtiimonas chitiniclastica is an emerging fly-borne zoonotic pathogen, which causes infections in immunocompromised patients and some animals. Herein, we reported a W. chitiniclastica BM-Y from a dead zebra in China.MethodsThe complete genome sequencing of BM-Y showed that this isolate carried one chromosome and one novel type of blaVEB–1-carrying plasmid. Detailed genetic dissection was applied to this plasmid to display the genetic environment of blaVEB–1.ResultsThree novel insertion sequence (IS) elements, namely ISWoch1, ISWoch2, and ISWoch3, were found in this plasmid. aadB, aacA1, and gcuG were located downstream of blaVEB–1, composing a gene cassette array blaVEB–1–aadB–aacA1–gcuG bracketed by an intact ISWoch1 and a truncated one, which was named the blaVEB–1 region. The 5′-RACE experiments revealed that the transcription start site of the blaVEB–1 region was located in the intact ISWoch1 and this IS provided a strong promoter for the blaVEB–1 region.ConclusionThe spread of the blaVEB–1-carrying plasmid might enhance the ability of W. chitiniclastica to survive under drug selection pressure and aggravate the difficulty in treating infections caused by blaVEB–1-carrying W. chitiniclastica. To the best of our knowledge, this is the first report of the genetic characterization of a novel blaVEB–1-carrying plasmid with new ISs from W. chitiniclastica

A clinical Pseudomonas juntendi strain with blaIMP−1 carried by an integrative and conjugative element in China

ObjectiveTo precisely determine the species of a carbapenem-resistant Pseudomonas strain 1809276 isolated from the urine of a Chinese patient and analyze its integrative and conjugative element (ICE) 1276 formation mechanism.MethodsSingle-molecule real-time (SMRT) sequencing was carried out on strain 18091276 to obtain the complete chromosome and plasmid (pCN1276) sequences, and average nucleotide identity (ANI) was used for precise species identification. The ICEs in GenBank with the same integrase structure as ICE 1276 were aligned. At the same time, the transfer ability of blaIMP−1 and the antibiotic sensitivity of Pseudomonas juntendi 18091276 were tested.ResultsThis bacterium was P. juntendi, and its drug resistance mechanism is the capture of the accA4' gene cassette by the Tn402-like type 1 integron (IntI1-blaIMP−1) to form In1886 before its capture by the ΔTn4662a-carrying ICE 1276. The acquisition of blaIMP−1 confers carbapenem resistance to P. juntendi 18091276.ConclusionThe formation of blaIMP−1-carrying ICE 1276, its further integration into the chromosomes, and transposition and recombination of other elements promote bacterial gene accumulation and transmission

Quality control of cell-based high-throughput drug screening

AbstractThe pharmaceutical industry is presently suffering difficult times due to low productivity of new molecular entities. As a major source of drug leads, high-throughput screening (HTS) has been often criticized for its ‘dead end’ lead compounds. However, the fruitful achievements resulting from HTS technology indicate that it remains a feasible way for drug innovation. Because of increasing considerations of earlier stage ADMET (absorption, distribution, metabolism, excretion and toxicity) in drug development, cell-based HTS is highly recommended in modern drug discovery for its ability to detect more biologically relevant characteristics of compounds in living systems. This review provides a systematic and practical description of vital points for conducting high quality cell-based HTS, from assay development to optimization, compound management, data analyses, hit validation as well as lead identification. Potential problems and solutions are also covered

The dynamics of carbon accumulation in Eucalyptus and Acacia plantations in the Pearl River delta region

<a>Abstract </a> <p><a></a><a><b><i>Key message </i></b></a><b>Plantation</b><b> type and age strongly influence the quantity of carbon stored in forest ecosystems. </b><b>The marked increase in total ecosystem carbon stock achieved over time by the <i>Eucalyptus</i> and <i>Acacia</i> plantations has confirmed that the afforestation of degraded soils can contribute positively to carbon sequestration.</b><b> </b><b></b></p> <p>·<b><i>Context</i></b> Reforestation has been widely conducted to restore and protect the eroded red soil in south China in recent decades. The question as to whether the<a></a><a> content of soil organic carbon (SOC) can be boosted by establishing </a>plantations of fast-growing tree species remains unresolved. </p> <p><b><i>·</i></b><b><i>Aim </i></b>We addressed whether the afforestation of degraded soils can contribute positively to carbon sequestration, and whether the accumulation of SOC is more effective under a nitrogen fixing species such as <i>Acacia</i> than under <i>Eucalyptus</i>.</p> <p>·<b><i>Methods</i></b> Here, a study was undertaken to measure the quantity of total ecosystem carbon (TEC) accumulated by plantations of both <i>Eucalyptus </i>and<i> Acacia</i> spp. in the Pearl River Delta region of southern China. </p> <p>·<b><i>Results </i></b>The quantity of TEC increased significantly with stand age in both plantation types (<i>P</i> < 0.05). The largest single component of TEC was SOC, with stand age having a considerable effect on both SOC and overall biomass. The accumulation of SOC in the top 100 cm of the soil profile was higher under <i>Acacia</i> than under <i>Eucalyptus</i> (<i>P </i>< 0.05). <b></b></p> <p>·<b><i>Conclusion </i></b>In terms of carbon sequestration, the afforestation of <i>Eucalyptus </i>and<i> Acacia</i> represent an effective forest management practice. The accumulation of SOC is more effective under <i>Acacia</i> than under <i>Eucalyptus</i><b></b></p

A Genome-Wide Survey of MATE Transporters in Brassicaceae and Unveiling Their Expression Profiles under Abiotic Stress in Rapeseed

The multidrug and toxic compound extrusion (MATE) protein family is important in the export of toxins and other substrates, but detailed information on this family in the Brassicaceae has not yet been reported compared to Arabidopsis thaliana. In this study, we identified 57, 124, 81, 85, 130, and 79 MATE genes in A. thaliana, Brassica napus, Brassica oleracea, Brassica rapa, Brassica juncea, and Brassica nigra, respectively, which were unevenly distributed on chromosomes owing to both tandem and segmental duplication events. Phylogenetic analysis showed that these genes could be classified into four subgroups, shared high similarity and conservation within each group, and have evolved mainly through purifying selection. Furthermore, numerous B. napusMATE genes showed differential expression between tissues and developmental stages and between plants treated with heavy metals or hormones and untreated control plants. This differential expression was especially pronounced for the Group 2 and 3 BnaMATE genes, indicating that they may play important roles in stress tolerance and hormone induction. Our results provide a valuable foundation for the functional dissection of the different BnaMATE homologs in B. napus and its parental lines, as well as for the breeding of more stress-tolerant B. napus genotypes

RESEARCH Open Access

cooperatively mediates GSK3-dependent Mcl-1 degradation induced by the Akt inhibitor API-1, resulting in apoptosi

Study of Micelle Formation by Fluorocarbon Surfactant <i>N</i>‑(2-hydroxypropyl)perfluorooctane Amide in Aqueous Solution

Micelles formed by fluorocarbon surfactant <i>N</i>-(2-hydroxypropyl)­perfluorooctane amide in aqueous solution were studied through surface tension, dynamic light scatting (DLS), isothermal titration calorimetry (ITC), and dissipative particle dynamic (DPD) simulations. Through surface tension measurements, the effectiveness of surface tension reduction, the maximum surface excess concentration, and the minimum area occupied per surfactant molecule at the air/water interface were investigated. The critical micelle concentration (cmc) at different temperatures and a series of thermodynamic parameters (Δ<i><i>G</i></i>_m^<i>0</i>, Δ<i><i>H</i></i>_m^<i>0</i>, Δ<i><i>S</i></i>_m^<i>0</i>, Δ<i><i>G</i></i>_ads^<i>0</i>, Δ<i>H</i>_m^<i>A</i> and Δ<i>C</i>_{p_m}⁰) of micellization were evaluated. The thermodynamic parameters showed that the micelle formation was entropy-driven. The micelle formation was also confirmed by ITC and DLS. In addition, the DPD simulations were conducted to simulate the whole process of micelle formation to make micelle formation better understood