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1.
Polymers (Basel) ; 14(9)2022 May 04.
Article in English | MEDLINE | ID: mdl-35567049

ABSTRACT

An isocyanate with trimethoxysilane groups at the side chains (IPDI-M) was synthesized via an addition between the mercaptopropyl trimethoxysilane groups (MPTMS) and IPDI tripolymer (IPDI-T). Then, silane grafted isocyanate as the functional hard segment, castor oil as the soft segment, poly (ethylene adipate) diol (PEA) as the chain extender, and MPTMS as an end-capping reagent were applied to form a series of organosilicon hybrid bio-based polyurethane (CPUSi). The effect of the IPDI-M contents on the thermal stability, mechanical properties, and surface properties of the resulting product was systematically investigated. Profit from the Si-O-Si crosslinked structures formed from MPTMS curing, the tensile strength, and Young's modulus of the resulting products increased from 9.5 MPa to 22.3 Mpa and 4.05 Mpa to 81.59 Mpa, respectively, whereas the elongation at break decreased from 342% to 101%. The glass transition temperature, thermal stability, transparency, hydrophobicity, and chemical resistance were remarkably strengthened for the obtained organosilicon-modified polyurethane with the increasing MPTMS content. At the end of the work, the thermal insulation coating that was based on CPUSi and ATO can effectively block near-infrared rays, and the temperature difference between the inside and outside of the film reached 15.1 °C.

2.
Clin Breast Cancer ; 21(6): 477-485, 2021 12.
Article in English | MEDLINE | ID: mdl-34635464

ABSTRACT

Antioxidant vitamin supplements (AVSs) are widely used among breast cancer survivors. Whether post-diagnosis use of AVSs would impair cancer survival is unclear. To assess the association between breast cancer survival and post-diagnosis AVSs use. We performed a literature search using PubMed, Cochrane Library, and Embase from their inception to October 1, 2020. Studies that investigated the association between breast cancer survival and post-diagnosis AVS use included. The AVSs included 1 or more of the following: vitamin A, C, or E. The meta-analysis included 8 studies with 17,062 patients. There was no significant difference between AVS use or not after diagnosis (HR 0.92, 95% CI 0•82-1•03) or during chemotherapy (HR 1.15, 95% CI 0.78-1.68) in overall survival (OS). Whenever during chemotherapy or after diagnosis, AVS users had a worse prognosis in the later studies. There was no significant inverse association between post-diagnosis vitamin A or E supplements use and OS. Vitamin C intake after breast cancer diagnosis was significantly associated with better OS (HR 0.84, 95% CI 0.76-0.93). Our findings suggest that post-diagnosis AVSs use would not worsen breast cancer survival, while vitamin C use after diagnosis might benefit OS. The discrepancy of survivals associated with post-diagnosis AVS use between earlier and later studies may cast doubt on the recommendation on guidelines. RCTs with large sample sizes are needed.


Subject(s)
Antioxidants/therapeutic use , Ascorbic Acid/therapeutic use , Breast Neoplasms/prevention & control , Cancer Survivors/statistics & numerical data , Dietary Supplements/statistics & numerical data , Primary Prevention/statistics & numerical data , Breast Neoplasms/drug therapy , Female , Health Status , Humans , Vitamin A/therapeutic use , Vitamin E/therapeutic use
3.
RSC Chem Biol ; 2(3): 743-758, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-34458809

ABSTRACT

Photoacoustic imaging (PAI), which integrates the higher spatial resolution of optical imaging and the deeper penetration depth of ultrasound imaging, has attracted great attention. Various photoacoustic probes including inorganic and organic agents have been well fabricated in last decades. Among them, small-molecule based agents are most promising candidates for preclinical/clinical applications due to their favorite in vivo features and facile functionalization. In recent years, PAI, in the near-infrared region (NIR, 700-1700 nm) has developed rapidly and has made remarkable achievements in the biomedical field. Compared with the visible light region (400-700 nm), it can significantly reduce light scattering and meanwhile provide deeper tissue penetration. In this review, we discuss the recent developments of near-infrared photoacoustic probes based on small molecule dyes, which focus on their "always on" and "activatable" form in biomedicine. Further, we also suggest current challenges and perspectives.

4.
mSystems ; 6(3): e0023721, 2021 Jun 29.
Article in English | MEDLINE | ID: mdl-34061620

ABSTRACT

The genus Acinetobacter comprises species with ecological significance and opportunistic pathogens and has a complicated taxonomy. Precise species identification is a foundation for understanding bacteria. In this study, we found and characterized two novel Acinetobacter species, namely, Acinetobacter tianfuensis sp. nov. and Acinetobacter rongchengensis sp. nov., based on phenotype examinations and genome analyses of the two strains WCHAc060012T and WCHAc060115T. The two strains had ≤89.69% (mean, 79.28% or 79.72%) average nucleotide identity (ANI) and ≤36.4% (mean, 20.89% or 22.19%) in silico DNA-DNA hybridization (isDDH) values compared with each other and all known Acinetobacter species. Both species can be differentiated from all hitherto known Acinetobacter species by a combination of phenotypic characteristics. We found that Acinetobacter pullorum B301T and Acinetobacter portensis AC 877T are actually the same species with 98.59% ANI and 90.4% isDDH values. We then applied the updated taxonomy to curate 3,956 Acinetobacter genomes in GenBank and found that 6% of Acinetobacter genomes (n = 234) are required to be corrected or updated. We identified 56 novel tentative Acinetobacter species, extending the number of Acinetobacter species to 144, including 68 with species names and 76 unnamed taxa. We also found that ANI and the average amino acid identity (AAI) values among type or reference strains of all Acinetobacter species and taxa are ≥76.97% and ≥66.5%, respectively, which are higher than the proposed cutoffs to define the genus boundary. This study highlights the complex taxonomy of Acinetobacter as a single genus and the paramount importance of precise species identification. The newly identified unnamed taxa warrant further studies. IMPORTANCE Acinetobacter species are widely distributed in nature and are of important ecological significance and clinical relevance. In this study, first, we significantly update the taxonomy of Acinetobacter by reporting two novel Acinetobacter species, namely, Acinetobacter tianfuensis and Acinetobacter rongchengensis, and by identifying Acinetobacter portensis as a synonym of Acinetobacter pullorum. Second, we curated Acinetobacter genome sequences deposited in GenBank (n = 3,956) using the updated taxonomy by correcting species assignations for 6% (n = 234) genomes and by assigning 94 (2.4%) to 56 previously unknown tentative species (taxa). Therefore, after curation, we further update the genus Acinetobacter to comprise 144 species, including 68 with species names and 76 unnamed taxa. Third, we addressed the question of whether such a large number of species should be divided in different genera and found that Acinetobacter is indeed a single genus. Our study significantly advanced the taxonomy of Acinetobacter, an important genus with science and health implications.

5.
Eur J Clin Microbiol Infect Dis ; 40(8): 1761-1766, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33595757

ABSTRACT

KPC-12 is a variant of KPC-2 with a L169M substitution in the Ω loop, but its resistance spectrum was not reported. blaKPC-12 was cloned, and KPC-12 exhibited significantly decreased activities against imipenem, meropenem, aztreonam, and piperacillin-tazobactam with ≥4-fold lower MICs than KPC-2. However, unlike the L169P substitution in KPC-35, activities against ceftazidime and ceftazidime-avibactam of KPC-12 were unaltered. This highlights that different substitutions at the same position of carbapenemases may have varied impact on the activity.


Subject(s)
Bacterial Proteins/metabolism , Drug Resistance, Multiple, Bacterial , Klebsiella pneumoniae/enzymology , beta-Lactamases/chemistry , beta-Lactamases/metabolism , Amino Acid Substitution , Gene Expression Regulation, Enzymologic , Humans , Klebsiella pneumoniae/drug effects , Microbial Sensitivity Tests , Models, Molecular , Mutation , Protein Conformation , beta-Lactamases/genetics
6.
Nanomaterials (Basel) ; 10(9)2020 Sep 06.
Article in English | MEDLINE | ID: mdl-32899956

ABSTRACT

In nanopharmaceutics, polymeric coating is a popular strategy for modifying the drug release kinetics and, thus, new methods for implementing the nanocoating processes are highly desired. In the present study, a modified coaxial electrospraying process was developed to formulate an ultra-thin layer of ethyl cellulose (EC) on a medicated composite core consisting of tamoxifen citrate (TAM) and EC. A traditional single-fluid blending electrospraying and its monolithic EC-TAM nanoparticles (NPs) were exploited to compare. The modified coaxial processes were demonstrated to be more continuous and robust. The created NPs with EC coating had a higher quality than the monolithic ones in terms of the shape, surface smoothness, and the uniform size distribution, as verified by the SEM and TEM results. XRD patterns suggested that TAM presented in all the NPs in an amorphous state thanks to the fine compatibility between EC and TAM, as indicated by the attenuated total reflection (ATR)-FTIR spectra. In vitro dissolution tests demonstrated that the NPs with EC coating required a time period of 7.58 h, 12.79 h, and 28.74 h for an accumulative release of 30%, 50%, and 90% of the loaded drug, respectively. The protocols reported here open a new way for developing novel medicated nanoparticles with functional coating.

7.
J Int Med Res ; 48(8): 300060520943473, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32762463

ABSTRACT

OBJECTIVE: This study compared the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) with conventional taxanes as neoadjuvant chemotherapy for breast cancer. METHODS: We searched the literature using PubMed, the Cochrane Library, and Web of Science from their inception to December 15, 2019 based on predetermined inclusion and exclusion criteria. The relevant studies compared pathologic complete response (pCR) and adverse event rates. RESULTS: The meta-analysis included five studies and 2335 patients. Compared with conventional taxanes, neoadjuvant chemotherapy with nab-paclitaxel was associated with a higher pCR rate (odds ratio [OR] = 1.39, 95% confidence interval [CI] = 1.16-1.67), especially among patients with triple-negative breast cancer or Ki67 indices of >20%. Pooled outcomes also revealed better event-free survival in the nab-paclitaxel group (hazard ratio = 0.69, 95% CI = 0.57-0.85). However, all-grade (OR = 2.17, 95% CI = 1.38-3.40) and grade ≥3 peripheral sensory neuropathy (OR = 3.92, 95% CI = 2.44-6.28) were more frequent in the nab-paclitaxel group. CONCLUSIONS: This meta-analysis implied that nab-paclitaxel more effectively improved pCR than conventional taxanes. Nab-paclitaxel may have greater benefits in patients with triple-negative breast cancer. However, additional attention is required for the early diagnosis and management of peripheral sensory neuropathy.


Subject(s)
Breast Neoplasms , Neoadjuvant Therapy , Albumins , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Humans , Paclitaxel/therapeutic use , Taxoids/therapeutic use
8.
Syst Appl Microbiol ; 43(4): 126092, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32690195

ABSTRACT

Two strains of the genus Acinetobacter, WCHAc060005T and WCHAc060007, were isolated from hospital sewage in China. The two strains showed different patterns of resistance to clinically important antibiotics and their taxonomic positions were investigated. Cells are Gram-negative, obligate aerobic, non-motile, catalase-positive and oxidase-negative coccobacilli. A preliminary analysis based on the 16S rRNA gene sequences indicated that the two strains had the highest similarity to Acinetobacter cumulans WCHAc060092T (99.02%). Whole-genome sequencing of the two strains and genus-wide phylogeny reconstruction based on a set of 107 Acinetobacter core genes indicated that they formed a separate and internally cohesive clade within the genus. The average nucleotide identity based on BLAST and in silico DNA-DNA hybridization values between the two new genomes were 99.77% and 98.7% respectively, whereas those between the two genomes and the known Acinetobacter species were <88.93% and <34.0%, respectively. A total of 7 different genes were found in the two genome sequences which encode resistance to five classes of antimicrobial agents, including clinically important carbapenems, oxyimino-cephalosporins, and quinolones. In addition, the combination of their ability to assimilate gentisate, but not l-glutamate and d,l-lactate could distinguish the two strains from all known Acinetobacter species. Based on these combined data, we concluded that the two strains represent a novel species of the genus Acinetobacter, for which the name Acinetobacter chengduensis sp. nov. is proposed. The type strain is WCHAc060005T (CCTCC AB 2019139=GDMCC 1.1622=JCM 33509).


Subject(s)
Acinetobacter/classification , Acinetobacter/physiology , Carbapenems/pharmacology , Drug Resistance, Bacterial/genetics , Sewage/microbiology , Acinetobacter/drug effects , Acinetobacter/genetics , Anti-Bacterial Agents/pharmacology , China , DNA, Bacterial/genetics , Drug Resistance, Bacterial/drug effects , Genes, Bacterial/genetics , Genome, Bacterial/genetics , Hospitals , Microbial Sensitivity Tests , Nucleic Acid Hybridization , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
9.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(2): 257-260, 2020 Mar.
Article in Chinese | MEDLINE | ID: mdl-32220197

ABSTRACT

This study is aimed to explore the value of metagenomic next-generation sequencing (mNGS) in diagnosing pathogen in fever patients. It is often a challenge to identify the pathogen that caused the infection in the HIV patients with fever. How could the mNGS be helpful for pathogen diagnosis is unclear. Here we reported a case of human immunodeficiency virus (HIV) patient with 2-month period of fever. After routine clinical laboratory tests including the conventional smear, culture, serological tests and pathological examinations, the causal pathogen still remained undiagnosed. Then the lymph node biopsy tissue was subjected to broad-range polymerase chain reaction (PCR) and the peripheral blood was subjected to mNGS. At the same time, peripheral blood culture was carried out with an extension of culture time to acquire the pathogen. Results from both broad-range PCR and mNGS revealed the pathogen was Talaromyces marneffei. The isolate recovered from the peripheral blood culture was subjected to the whole-genome sequencing. Whole genome sequencing revealed that the antimicrobial resistance gene FLU1 existed in this pathogen's genome, but mNGS did not detect the FLU1 gene. Phylogenetic analysis based on whole genome sequence revealed that this isolate was far from other clones published in NCBI database. Here we reported a case of Talaromyces marneffei infection diagnosed by mNGS, showing that mNGS is helpful in etiological diagnosis for HIV patients with unexplained fever. However, application of mNGS in antimicrobial resistant genes detection and pathogen tracing need to be well-studied in the future.


Subject(s)
HIV Infections , High-Throughput Nucleotide Sequencing , Metagenomics , Fever/etiology , HIV Infections/complications , HIV Infections/diagnosis , HIV Infections/genetics , Humans , Phylogeny , Polymerase Chain Reaction
10.
Anal Chem ; 91(20): 13285-13289, 2019 10 15.
Article in English | MEDLINE | ID: mdl-31532627

ABSTRACT

Design and fabrication of smart liquid quantum dots (LQDs) with high biomolecule selectivity and specificity remains a challenge. Herein, a multifunctional calix[4]arene derivative (PCAD) was rationally designed and applied to fabricate a Tyr-responsive CdSe-LQD system through host-guest chemistry. Such a biosensor displays an outstanding fluorescence/macroscopic response for Tyr and reversible fluidic features due to the hydrogen interaction between the PCAD of CdSe-LQDs and Tyr. These excellent results highlighted CdSe-LQDs as a promising platform for biological molecule recognition and separation in the future.


Subject(s)
Biosensing Techniques/methods , Quantum Dots/chemistry , Tyrosine/analysis , Cadmium Compounds/chemistry , Calixarenes/chemistry , Limit of Detection , Selenium Compounds/chemistry , Spectrometry, Fluorescence/methods
11.
Luminescence ; 34(8): 903-910, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31364263

ABSTRACT

In this paper, a new 'turn-on' fluorescence probe for the rapid, sensitive, and visual detection of hypochlorite is reported. The push-pull type trianiline-tricyanofuran-based fluorescent probe was prepared using a condensation reaction between tricyanofuran and the thiophene-trianiline derivative that had high quantum yields and showed aggregation-induced emission enhanced properties. Upon exposure to hypochlorite, prominent fluorescence enhancement of the probe was observed via the release of the fluorophore from the probe. The probe showed a ratiometric absorption change at 315 nm and 575 nm. Importantly, the probe showed an excellent detection limit for hypochlorite at 1.2 × 10-7  M in solution and it was successfully applied for monitoring hypochlorite in waste water by test strip. This work reports a new fluorescence analytical sensing method for hypochlorite that has potential practical value in environmental monitoring and biological discrimination.


Subject(s)
Fluorescent Dyes/chemistry , Hypochlorous Acid/analysis , Water Pollutants, Chemical/analysis , Fluorescent Dyes/chemical synthesis , Molecular Structure , Spectrometry, Fluorescence
12.
Luminescence ; 34(6): 615-622, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31106961

ABSTRACT

A new near-infrared fluorescence sensor PDI-PD for Ag+ ions was successfully prepared and its structure characterized by 1 H nuclear magnetic resonance (NMR), 13 C NMR and high-resolution mass spectrometry; matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (HRMS MALDI-TOF). The probe exhibited rapid, sensitive, and selective two-channel fluorescence responses towards Ag+ ions and protons. The probe has a marked high binding affinity and high sensitivity for Ag+ , with a detection limit of 1.4 × 10-6  M. An approximately five-fold enhanced core emission at 784 nm was attributed to fluorescence resonance energy transfer (FRET). The enhanced core emission of the probe with Ag+ ions based on photo-induced electron transfer and FRET is discussed. In addition, the probe presented a visible colour change. All experimental results demonstrated that PDI-PD is an efficient tool for the selective, sensitive and rapid detection of Ag+ ions and protons using two-channel fluorescence responses.


Subject(s)
Dendrimers/chemistry , Silver/chemistry , Spectrometry, Fluorescence/methods , Dendrimers/chemical synthesis , Fluorescence , Fluorescence Resonance Energy Transfer , Limit of Detection
13.
Pharmaceutics ; 11(5)2019 May 10.
Article in English | MEDLINE | ID: mdl-31083358

ABSTRACT

In pharmaceutical nanotechnology, the intentional manipulation of working processes to fabricate nanoproducts with suitable properties for achieving the desired functional performances is highly sought after. The following paper aims to detail how a modified coaxial electrospraying has been developed to create ibuprofen-loaded hydroxypropyl methylcellulose nanoparticles for improving the drug dissolution rate. During the working processes, a key parameter, i.e., the spreading angle of atomization region (θ, °), could provide a linkage among the working process, the property of generated nanoparticles and their functional performance. Compared with the applied voltage (V, kV; D = 2713 - 82V with RθV2 = 0.9623), θ could provide a better correlation with the diameter of resultant nanoparticles (D, nm; D = 1096 - 5θ with RDθ2 = 0.9905), suggesting a usefulness of accurately predicting the nanoparticle diameter. The drug released from the electrosprayed nanoparticles involved both erosion and diffusion mechanisms. A univariate quadratic equation between the time of releasing 95% of the loaded drug (t, min) and D (t = 38.7 + 0.097D - 4.838 × 105D2 with a R2 value of 0.9976) suggests that the nanoparticle diameter has a profound influence on the drug release performance. The clear process-property-performance relationship should be useful for optimizing the electrospraying process, and in turn for achieving the desired medicated nanoparticles.

14.
Proc Natl Acad Sci U S A ; 116(6): 1968-1973, 2019 02 05.
Article in English | MEDLINE | ID: mdl-30670648

ABSTRACT

Fluorescent theranostics probes at the second near-IR region (NIR-II; 1.0-1.7 µm) are in high demand for precise theranostics that minimize autofluorescence, reduce photon scattering, and improve the penetration depth. Herein, we designed and synthesized an NIR-II theranostic nanoprobe 1 that incorporates a Pt(II) metallacycle 2 and an organic molecular dye 3 into DSPE-mPEG5000 (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-5000]). This design endows 1 with good photostability and passive targeting ability. Our studies show that 1 accurately diagnoses cancer with high resolution and selectively delivers the Pt(II) metallacycle to tumor regions via an enhanced permeability and retention effect. In vivo studies reveal that 1 efficiently inhibits the growth of tumor with minimal side effects. At the same time, improved fluorescent imaging quality and signal-to-noise ratios are shown due to the long emission wavelengths. These studies demonstrate that 1 is a potential theranostic platform for tumor diagnosis and treatment in the NIR-II region.


Subject(s)
Neoplasms/diagnostic imaging , Neoplasms/therapy , Theranostic Nanomedicine/methods , Animals , Magnetic Resonance Imaging , Mice , Mice, Inbred C57BL , Neoplasms, Experimental/diagnostic imaging , Neoplasms, Experimental/therapy , Photons , Signal-To-Noise Ratio
15.
Chem Sci ; 9(19): 4370-4380, 2018 May 21.
Article in English | MEDLINE | ID: mdl-29896378

ABSTRACT

In recent years, owing to unsatisfactory clinical imaging clarity and depths in the living body for early diagnosis and prognosis, novel imaging modalities with high bioimaging performance have been actively explored. The remarkable headway made in the second near-infrared region (NIR-II, 1000-1700 nm) has promoted the development of biomedical imaging significantly. NIR-II fluorescence imaging possesses a number of merits which prevail over the traditional and NIR-I (400-900 nm) imaging modalities in fundamental research, such as reduced photon scattering, as well as auto-fluorescence and improved penetration depth. Functional probes for instant and precise feedback of in vivo information are at the core of this modality for superb imaging. Herein, we review the recently developed fluorophores including carbon nanotubes, organic small molecules, quantum dots, conjugated polymers and rare-earth-doped materials to present superior and multifunctionality of biomedical imaging in the NIR-II regions (1000-1700 nm).

16.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(1): 136-139, 2018 Jan.
Article in Chinese | MEDLINE | ID: mdl-29737105

ABSTRACT

OBJECTIVE: To analyze the clinical characteristics of infective endocarditis (IE) in culture-positive patients,so as to provide the evidences for reasonable diagnosis and treatment of IE. METHODS: We performed a retrospective study of 157 culture-positive IE cases,which were diagnosed according to modified Duke criteria for IE from Jan. 2008 to Aug. 2015. RESULTS: The average age of 157 cases of IE was 40.85 years. One hundred and one patients (64.3%) had various underlying cardiac diseases,including congenital cardiovascular diseases in 44 cases and rheumatic heart diseases in 15 cases. The main clinical manifestations were anemia (147 cases,93.6%),fever(137 cases,87.3%) and heart murmur (120 cases,76.4%). Vegetation was found in 12 cases (7.6%) with transesophageal echocardiography (TEE) but not with transthoracic echocardiography (TTE) . Culture results showed the most common causative microorganisms were Streptococci (76 cases,48.4%),with Viridans streptococci dominated in 70 cases,and Staphylococci (33 cases,21.0%) (Staphylococcus aureus dominated in 18 cases). All patients were treated with antimicrobial agents. Eighty-five patients (54.1%) received surgical intervention,of which 72 cases received valve replacement. Twenty-seven patients were cured,88 patients were markedly improved,38 patients discontinued treatment,and 4 patients died. The therapeutic efficacy of operation group was better. CONCLUSION: The clinical characteristics of IE included: the age of onset increased,congenital heart disease was the most underlying disease,and Viridians streptococci was the most popular causative microorganism. Surgical therapy can effectively improve the outcomes of IE patients.


Subject(s)
Endocarditis, Bacterial/epidemiology , Staphylococcal Infections/epidemiology , Streptococcal Infections/epidemiology , Adult , Age of Onset , Endocarditis, Bacterial/drug therapy , Endocarditis, Bacterial/surgery , Heart Defects, Congenital/complications , Humans , Retrospective Studies , Staphylococcal Infections/drug therapy , Staphylococcus aureus , Streptococcal Infections/drug therapy , Viridans Streptococci
17.
Arch Microbiol ; 200(3): 423-429, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29184975

ABSTRACT

A novel Gram-staining positive, moderately halophilic, endospore-forming, motile, rod-shaped and strictly aerobic strain, designated YIM 93565T, was isolated from a salt lake in Xinjiang province of China and subjected to a polyphasic taxonomic study. Strain YIM 93565T grew in the range of pH 6.0-9.0 (optimum pH 7.0), 10-45 °C (optimum 35-40 °C) and at salinities of 2-24% (w/v) NaCl (optimum 7-10%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 93565T clustered with members of the genera Gracilibacillus and form a clade with Gracilibacillus bigeumensis KCTC 13130T (95.6% similarity) and Gracilibacillus halophilus DSM 17856T (94.9%), which was well separated from others. The DNA G + C content of this novel strain was 36.8 mol%. The major fatty acids were anteiso-C15:0, iso-C15:0, C16:0 and anteiso-C17:0 and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, one unidentified glycolipid and two unidentified phospholipids. The predominant menaquinone was MK-7. The cell-wall peptidoglycan was based on meso-diaminopimelic acid. Based on the results of phylogenetic, physiological and chemotaxonomic comparative analyses, the isolate is assigned to a novel species of the genus Gracilibacillus, for which the name Gracilibacillus eburneus sp. nov. is proposed, with the type strain YIM 93565T (= DSM 23710T = CCTCC AB 2013249T).


Subject(s)
Bacillaceae/classification , Bacillaceae/genetics , Bacillaceae/isolation & purification , Base Composition , Cell Wall/chemistry , China , DNA, Bacterial/genetics , Diaminopimelic Acid/analysis , Diaminopimelic Acid/chemistry , Fatty Acids/analysis , Fatty Acids/chemistry , Lakes/microbiology , Molecular Typing , Phospholipids/analysis , Phospholipids/chemistry , Phylogeny , RNA, Ribosomal, 16S/genetics , Salt Tolerance , Water Microbiology
18.
Front Microbiol ; 8: 2094, 2017.
Article in English | MEDLINE | ID: mdl-29118748

ABSTRACT

The plasmid-borne colistin-resistant gene mcr-1 has rapidly become a worldwide public health concern. This study aims to determine the host bacterial strains, plasmids, and genetic contexts of mcr-1 in hospital sewage. A 1-ml hospital sewage sample was cultured. Colistin-resistant bacterial colonies were selected on agar plates and were subjected to whole genome sequencing and subsequent analysis. The transfer of mcr-1 between bacterial strains was tested using conjugation. New variants of mcr-1 were cloned to test the impact of variations on the function of mcr-1. Plasmids carrying mcr-1 were retrieved from GenBank for comparison based on concatenated backbone genes. In the sewage sample, we observed that mcr-1 was located in various genetic contexts on the chromosome, or plasmids of four different replicon types (IncHI2, IncI2, IncP, and IncX4), in Klebsiella pneumoniae, Kluyvera spp. and seven Escherichia coli strains of six different sequence types (ST10, ST34, ST48, ST1196, ST7086, and ST7087). We also identified two new variants of mcr-1, mcr-1.4 and mcr-1.7, both of which encode an amino acid variation from mcr-1. mcr-1-carrying IncX4 plasmids, which have a global distribution across the Enterobacteriaceae, are the result of global dissemination of a single common plasmid, while IncI2 mcr-1 plasmids appear to acquire mcr-1 in multiple events. In conclusion, the unprecedented remarkable diversity of species, strains, plasmids, and genetic contexts carrying mcr-1 present in a single sewage sample from a single healthcare site highlights the continued evolution and dynamic transmission of mcr-1 in healthcare-associated environments.

19.
Sci Rep ; 7: 43555, 2017 03 06.
Article in English | MEDLINE | ID: mdl-28262711

ABSTRACT

Clostridium difficile consists of six clades but studies on Clade 3 are limited. Here, we report genome sequences of three Clade 3 C. difficile strains carrying genes encoding toxin A and B and the binary toxin. Isolates 103 and 133 (both of ST5) and isolate 106 (ST285) were recovered from three ICU patients. Whole genome sequencing using HiSeq 2500 revealed 4.1-Mb genomes with 28-29% GC content. There were ≥1,104 SNP between the isolates, suggesting they were not of a single clone. The toxin A and B gene-carrying pathogenicity locus (PaLoc) of the three isolates were identical and had the insertion of the transposon Tn6218. The genetic components of PaLoc among Clade 3 strains were the same with only a few nucleotide mutations and deletions/insertions, suggesting that the Tn6218 insertion might have occurred before the divergence within Clade 3. The binary toxin-genes carrying CDT locus (CdtLoc) of the three isolates were identical and were highly similar to those of other Clade 3 strains, but were more divergent from those of other clades. In conclusion, Clade 3 has an unusual clade-specific PaLoc characteristic of a Tn6218 insertion which appears to be the main feature to distinguish Clade 3 from other C. difficile.


Subject(s)
Bacterial Toxins/genetics , Clostridioides difficile/classification , Clostridioides difficile/genetics , Clostridium Infections/epidemiology , Clostridium Infections/microbiology , Genome, Bacterial , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , China/epidemiology , Clostridioides difficile/drug effects , Clostridioides difficile/isolation & purification , Drug Resistance, Bacterial , Gene Order , Humans , Microbial Sensitivity Tests , Multilocus Sequence Typing , Phylogeny , Polymorphism, Single Nucleotide
20.
BMC Infect Dis ; 17(1): 51, 2017 01 10.
Article in English | MEDLINE | ID: mdl-28068915

ABSTRACT

BACKGROUND: The incidence of cryptococcal meningitis (CM) and tuberculous meningitis (TBM) have gradually increased in recent years. These two types of meningitis are easily misdiagnosed which leads to a poor prognosis. In this study we compared differences of clinical features and prognostic factors in non-HIV adults with CM and TBM. METHODS: We retrospectively reviewed the medical records of CM and TBM patients from January 2008 to December 2015 in our university hospital in China. The data included demographic characteristics, laboratory results, imaging findings, clinical outcomes. RESULTS: A total of 126 CM and 105 TBM patients were included. CM patients were more likely to present with headache, abnormal vision and hearing, and they might be less prone to fever and cough than TBM patients (P < 0.05). Higher percentage of CM patients presented with cerebral ischemia/infarction and demyelination in brain MRI than TBM patients (P < 0.05). CM patients had lower counts of WBC in CSF, lower total protein in CSF and serum CD4/CD8 ratio than TBM patients (P < 0.05). After three months of treatment, CM group have worse outcome than TBM group (P < 0.05). Multivariate analysis showed that age more than 60y (OR = 4.981, 95% CI: 1.955-12.692, P = 0.001), altered mentation (OR = 5.054, 95% CI: 1.592-16.046, P = 0.006), CD4/CD8 ratios < 1 (OR = 8.782, 95% CI: 2.436-31.661, P = 0.001) and CSF CrAg ≥ 1:1024 (OR = 4.853, 95% CI: 1.377-17.098, P = 0.014) were independent risk factors for poor prognosis for CM patients. For TBM patients, hydrocephalus (OR = 7.290, 95% CI: 1.630-32.606, P = 0.009) and no less than three underlying diseases (OR = 6.899, 95% CI: 1.766-26.949, P = 0.005) were independent risk factors, headache was a protective factor of prognosis. CONCLUSIONS: Our study provided some helpful clues in the differential diagnosis of non-HIV patients with CM or TBM and identified some risk factors for the poor prognosis of these two meningitis which could help to improve the treatment outcome. Further studies are worth to be done.


Subject(s)
Meningitis, Cryptococcal/diagnosis , Tuberculosis, Meningeal/diagnosis , Adult , Antigens, Fungal/cerebrospinal fluid , Brain Ischemia/diagnostic imaging , Brain Ischemia/etiology , Cerebral Infarction/diagnostic imaging , Cerebral Infarction/etiology , China , Comorbidity , Cough/etiology , Demyelinating Diseases/diagnostic imaging , Demyelinating Diseases/etiology , Diagnosis, Differential , Female , Headache/etiology , Hospitals, University , Humans , Hydrocephalus/etiology , Magnetic Resonance Imaging , Male , Meningitis, Cryptococcal/cerebrospinal fluid , Meningitis, Cryptococcal/complications , Meningitis, Cryptococcal/therapy , Middle Aged , Multivariate Analysis , Prognosis , Retrospective Studies , Risk Factors , Time-to-Treatment , Treatment Outcome , Tuberculosis, Meningeal/complications , Tuberculosis, Meningeal/therapy
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