10 results on '"Changyun Ye"'
Search Results
2. Rapid, sensitive and reliable detection of Klebsiella pneumoniae by label-free multiple cross displacement amplification coupled with nanoparticles-based biosensor
- Author
-
Changyun Ye, Yi Wang, Yan Wang, Weiqiang Yan, and Jianguo Xu
- Subjects
DNA, Bacterial ,0301 basic medicine ,Microbiology (medical) ,Time Factors ,Klebsiella pneumoniae ,030106 microbiology ,Antarctic Regions ,Biosensing Techniques ,Sensitivity and Specificity ,Microbiology ,03 medical and health sciences ,Uracil-DNA Glycosidase ,Molecular Biology ,Pathogen ,Label free ,Bacteriological Techniques ,Chromatography ,Base Sequence ,biology ,Thermal sensitive ,Chemistry ,Temperature ,Contamination ,biology.organism_classification ,Klebsiella Infections ,030104 developmental biology ,Genes, Bacterial ,Clinical diagnosis ,Nanoparticles ,Severe morbidity ,Nucleic Acid Amplification Techniques ,Biosensor - Abstract
Klebsiella pneumoniae ( K. pneumoniae ), as an important hospital-acquired bacterium, is responsible for severe morbidity and mortality among the elderly, newborn and immune-compromised people. We established a rcsA gene-based label-free multiple cross displacement amplification (MCDA) assay for rapid, simple and sensitive detection of K. pneumoniae by using lateral flow biosensor (LFB). MCDA reaction was conducted at a fixed temperature (65 °C) for only 30 min, and amplification results were directly indicated using LFB. The results showed that reaction products were detectable from as little as 100 fg and 4.8 CFU of pure K. pneumoniae templates, and from approximately 480 CFU in 1 mL of spiked clinical samples. All K. pneumoniae strains examined were positive for label-free MCDA-LFB analysis, and all non- K. pneumoniae strains used in the report were negative for label-free MCDA-LFB assay, indicating the high selectivity of the label free MCDA-LFB assay. Furthermore, to remove false-positive results, the label-free MCDA-LFB assay was supplemented with antarctic thermal sensitive uracil-DNA-glycosylase (AUDG) to eliminate the carryover contamination. Thus, label-free MCDA-LFB assay complemented with AUDG enzyme was a rapid, simple, sensitive and reliable technique for detection of target pathogen, which has the ability to effectively avoid carryover contamination, and can be a valuable tool for “on-site” detection, clinical diagnosis, and primary quarantine purposes.
- Published
- 2018
3. Nanoparticles-based lateral flow biosensor coupled with multiple cross displacement amplification Plus for simultaneous detection of nucleic acid and prevention of carryover contamination
- Author
-
Jianguo Xu, Dongxin Liu, Jianping Deng, Changyun Ye, Yi Wang, and Yan Wang
- Subjects
0301 basic medicine ,Chromatography ,Thermal sensitive ,biology ,Chemistry ,Metals and Alloys ,Analytical chemistry ,Loop-mediated isothermal amplification ,Target analysis ,Contamination ,Condensed Matter Physics ,biology.organism_classification ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,False-positive result ,03 medical and health sciences ,030104 developmental biology ,Mycobacterium tuberculosis complex ,Materials Chemistry ,Nucleic acid ,Electrical and Electronic Engineering ,Instrumentation ,Biosensor - Abstract
Isothermal amplification techniques, which avoid thermal cycling, are often confounded by non-specific amplification arising from off-target hybrids, interactions between (hetero-dimer) or within (self-dimerization) primers and carryover contaminants. Here, we developed a new method, termed multiple cross displacement amplification Plus (MCDA Plus), which uses self-avoiding molecular recognition system (SAMRS) components and antarctic thermal sensitive uracil-DNA-glycosylase (AUDG) enzyme to improve the specificity of MCDA and prevent carryover contamination, respectively. In the presence of SAMRS components, the false positive results arising from off-target hybrids and undesired interactions between or within primers are completely eliminated, which increase the reproducibility of the assay. In the presence of AUDG, the false positive results generating from carryover contaminants are removed, thus the genuine positive results are obtained from the amplification of target sequences. Moreover, we also devised a new analysis strategy, which was intended for the detection of amplified products using lateral flow biosensor (LFB). The analysis system only required a single labeled primer, thus eliminated the false positive result yielding from hybridization (the labeled primer and probe, or between two labeled primers). Therefore, the SAMRS components, AUDG and LFB convert standard MCDA from an assay suited only for the research laboratory into one that has applicable value at points-of-care testing, in the field environments and in poor-resource settings. For demonstration purpose, Mycobacterium tuberculosis complex (MTC), which is the causes of human Tuberculosis (TB), are detected by the novel MCDA Plus technique to demonstrate the capability of target analysis. The performance of MCDA Plus assay in identifying MTC from pure culture and clinical samples is successfully evaluated. The proof-of-concept technique can be reconfigured to detect various nucleic acid sequences by redesigning the specific MCDA Plus primers.
- Published
- 2018
4. Function and distribution of the conjugative plasmid pLM1686 in foodborne Listeria monocytogenes in China
- Author
-
Shunshi Ji, Huaying Jiang, Pan Mao, Hui Sun, Lingling Li, Zexuan Song, Lin Gan, Yiqian Wang, Changyun Ye, and Yan Wang
- Subjects
Serotype ,Cell invasion ,China ,0303 health sciences ,Strain (chemistry) ,030306 microbiology ,Conjugative plasmid ,Biofilm ,General Medicine ,Biology ,Serogroup ,medicine.disease_cause ,Adaptation, Physiological ,Listeria monocytogenes ,Microbiology ,03 medical and health sciences ,Plasmid ,medicine ,Function (biology) ,Plasmids ,030304 developmental biology ,Food Science - Abstract
Listeria monocytogenes, a fatal foodborne pathogen has the extraordinary capacity to survive in harsh conditions and is a potential threat to public health. A novel 91 kb plasmid pLM1686 was found in the prevalent L. monocytogenes sequence type (ST) 87 strain in China. In this study, the function and distribution of pLM1686 were firstly investigated in L. monocytogenes. The results showed plasmid pLM1686 had self-transmissible ability and existed in various types of L. monocytogenes isolates belonging to two lineages (lineage I and II), four serotypes (1/2b, 3b, 1/2c and 1/2a) and four STs (ST87, ST59, ST9 and ST120). The wild strain LM1686 and transconjugant strain 10403SP1686 exhibited significantly higher growth rate and biofilm formation in Modification of Welshimer's medium (MWB), greater salinity tolerance, stronger cell invasion and higher cytotoxicity than plasmid-cured strain and reference strain 10403S. Moreover, plasmid curing caused the loss of cadmium resistance of strain, and the recipient strain acquired cadmium resistance after conjugation. Thus, pLM1686 would provide L. monocytogenes advantages of surviving in adverse environments.
- Published
- 2021
5. Development of a Novel Listeria Enrichment Broth for the Isolation of Pathogenic Listeria
- Author
-
Lijuan Luo, Yi Wang, Yan Wang, Dongxin Liu, Changyun Ye, Kai Liu, and Lu Zhang
- Subjects
0301 basic medicine ,Enrichment broth ,Listeria ,Microorganism ,030106 microbiology ,medicine.disease_cause ,Microbiology ,Isolation rate ,03 medical and health sciences ,Listeria monocytogenes ,medicine ,Humans ,Listeriosis ,biology ,Chemistry ,Isolation (microbiology) ,biology.organism_classification ,Culture Media ,030104 developmental biology ,Food Microbiology ,Listeria ivanovii ,Bacteria ,Food Science - Abstract
Listeriosis, the disease caused by pathogenic Listeria species, can present severe symptoms in susceptible people. The goal of this study was to develop a novel enrichment broth, Listeria allose enrichment broth (LAEB), to improve isolation of Listeria monocytogenes and Listeria ivanovii from samples through incorporating a specific carbohydrate and reducing inhibitor concentrations. Other coexisting bacteria, particularly Listeria innocua, can interfere with the isolation of pathogenic Listeria in such ways as overgrowth of L. innocua and the generation of inhibitory metabolites. The incorporation of allose into the novel LAEB was effective for slowing the growth of L. innocua and other nontarget microorganisms. We determined that 35°C and pH 7.0 under aerobic conditions are optimal for Listeria growth in this medium. The novelty of the use of LAEB is the single enrichment procedure at 35°C for 24 h, obviating the need for a secondary enrichment medium. In 50 simulated samples, the sensitivity of the LAEB method (86%) was higher than that of the International Organization for Standardization (EN ISO) method (70%). In 142 naturally contaminated samples tested, the isolation rate for pathogenic Listeria with the LAEB method was 26.0% (37 of 142 samples), which was significantly higher than the 17.6% (25 of 142 samples) for the EN ISO method. Higher isolation rates and a quicker and easier protocol make the novel LAEB method an appropriate alternative for the isolation of pathogenic Listeria.
- Published
- 2017
6. A 12-month longitudinal study of Listeria monocytogenes contamination and persistence in pork retail markets in China
- Author
-
Yimao Miao, Lijuan Luo, Jianping Deng, Pengfei Wang, Yang Zhou, Xiang Liu, Ling Zhang, Jianguo Xu, Qun Li, Yi Wang, Ruiting Lan, Yan Wang, Songsong Sun, Xi Chen, Hong Wang, Zhengdong Zhang, and Changyun Ye
- Subjects
0301 basic medicine ,Serotype ,Veterinary medicine ,Longitudinal study ,business.industry ,030106 microbiology ,Biology ,Contamination ,Sequence types ,medicine.disease_cause ,Biotechnology ,Persistence (computer science) ,03 medical and health sciences ,030104 developmental biology ,Listeria monocytogenes ,Pulsed-field gel electrophoresis ,medicine ,Multilocus sequence typing ,business ,Food Science - Abstract
Listeria monocytogenes is a foodborne pathogen frequently isolated from raw pork meat. This study was designed to investigate the prevalence and molecular characteristics of L. monocytogenes in raw pork from open markets in China. The survey was conducted monthly over a 12-month period in Zigong, China. L. monocytogenes was isolated from 262 of 1641 samples collected (16.0%) including minced meat samples (131/608, 21.5%), pork pieces samples (111/857, 13.0%) and environmental swabs (20/176, 11.4%). The isolation rates in spring and winter were significantly higher than those in summer and autumn ( X 2 = 68.85, P AscI pulsed-field gel electrophoresis (PFGE). The 262 isolates were subtyped into five serotypes: 1/2b (43.1%), 1/2c (35.5%), 1/2a (19.1%), 4b (1.1%), 3a (1.1%); 20 sequence types (STs) with four most frequent STs, being ST9 (35.9%), ST87 (19.8%), ST3 (16.0%) and ST8 (14.1%); and 39 pulsotypes (PTs) with PT4 (26.3%), PT30 (14.5%) and PT11 (12.6%) being most frequent. Two primary pulsotypes from pork pieces were previously isolated from clinical listeriosis cases in the local hospitals. The six markets from different districts differed in the level of contamination and strain types. Persistent contamination of L. monocytogenes was found in the markets especially in meat mincers, which were found to be one likely source of continuous cross contamination. These findings will help develop strategies to reduce L. monocytogenes contamination in open markets for better public health control and prevention of foodborne L. monocytogenes infections.
- Published
- 2017
7. Visual and multiplex detection of nucleic acid sequence by multiple cross displacement amplification coupled with gold nanoparticle-based lateral flow biosensor
- Author
-
Yi Wang, Changyun Ye, Yan Wang, Lu Zhang, and Jianguo Xu
- Subjects
0301 basic medicine ,Materials science ,Chromatography ,Metals and Alloys ,Nucleic acid sequence ,Analytical chemistry ,Nanoparticle ,Target analysis ,Amplicon ,Condensed Matter Physics ,Displacement (vector) ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Field detection ,03 medical and health sciences ,030104 developmental biology ,Materials Chemistry ,Multiplex ,Electrical and Electronic Engineering ,Instrumentation ,Biosensor - Abstract
Here, we reported on the establishment of a nearly instrument free, simple and rapid molecular technique, which incorporated multiple cross displacement amplification coupled with lateral flow biosensor (MCDA-LFB) for the visual, sensitive and specific detection of nucleic acid sequence. The MCDA-LFB assay was able to simultaneously detect and correctly differentiate multiple targets using a 40 min amplification reaction followed by a 2 min incubation of the products on the visualization biosensor. The biosensor was devised to detect three targets, a chromatography control, the MCDA target amplicon I and II, and the interpretation of test results is based on the appearance of red lines on the reaction pad. As a proof of concept, Shigella and Salmonella strains were detected by MCDA-LFB technique to demonstrate the availability of target analysis. The analytical sensitivity, specificity and practical application of MCDA-LFB assay were successfully evaluated in pure culture and blood samples, and the whole procedure, including specimen (blood sample) processing (35 min), isothermal reaction (40 min), and result reporting (5 min), was completed within 80 min. Therefore, the simplicity, rapidity and nearly apparatus-free platform of the MCDA-LFB assay make it practical for point-of-care testing, field detection, ‘on-site’ diagnosis and more.
- Published
- 2017
8. The genetically modified suilysin, rSLYP353L, provides a candidate vaccine that suppresses proinflammatory response and reduces fatality following infection with Streptococcus suis
- Author
-
Huamao Du, Hefang Xie, Jianguo Xu, Huaiqi Jing, Changyun Ye, Wei Huang, and Zhihong Ren
- Subjects
Streptococcus suis ,Hemagglutination ,Swine ,Molecular Sequence Data ,Inflammation ,Biology ,Virulence factor ,Microbiology ,Proinflammatory cytokine ,Pathogenesis ,Hemolysin Proteins ,Mice ,Streptococcal Infections ,medicine ,Animals ,General Veterinary ,General Immunology and Microbiology ,Interleukin-6 ,Streptococcal Vaccines ,Public Health, Environmental and Occupational Health ,biology.organism_classification ,Interleukin-10 ,Mice, Inbred C57BL ,Infectious Diseases ,Amino Acid Substitution ,Immunization ,Immunology ,Molecular Medicine ,Female ,Tumor necrosis factor alpha ,medicine.symptom - Abstract
Streptococcus suis is a persistent global hazard in the swine industry and an emerging threat to public health. The high mortality in China following outbreaks of streptococcal toxic shock syndrome (STSS) underscores the urgency for effective prevention. A limited understanding of the pathogenesis of S. suis in STSS may explain the lack of biological products for prevention. Suilysin (SLY) is an important virulence factor in the pathogenesis of S. suis. To identify a candidate vaccine for S. suis-induced STSS, we constructed a recombinant non-hemolytic mutant of SLY that has hemagglutination activity, rSLYP353L, and evaluated its ability to induce inflammatory response and prevent fatal S. suis infection in mice. The rSLYP353L mutant, as compared with hemolytic rSLY, elicited lower levels of IL-6, KC and IL-10 at 3 h and 5 h post-treatment (p < 0.05), indicating that hemolytic activity is associated with rSLY-mediated inflammation. Furthermore, passive immunization with anti-SLYP353L antisera protected mice from acute death after infection with S. suis SC84 (p < 0.05). Effects were not due to protection against tissue damage, as S. suis SC84 caused no detectable histopathological lesions in mice within 24 h. However, immunization with rSLYP353L caused significantly reduced levels of KC and IL-1β at 6 and 9 h post-challenge and IL-6 at 9 h post-challenge (p < 0.05). In conclusion, rSLYP353L may provide a potential vaccine for protection against S. suis-induced STSS due to its reduction in proinflammatory response early in S. suis infection.
- Published
- 2013
9. A cleavable signal peptide is required for the full function of the polytopic inner membrane protein FliP of Escherichia coli
- Author
-
Long-Fei Wu, Changyun Ye, and Nathalie Pradel
- Subjects
Signal peptide ,Escherichia coli Proteins ,Recombinant Fusion Proteins ,Mutant ,Biophysics ,Wild type ,Membrane Proteins ,Cell Biology ,Protein Sorting Signals ,Flagellum ,Biology ,Biochemistry ,Transmembrane domain ,Membrane protein ,Cell Movement ,Flagella ,Flip ,Escherichia coli ,Inner membrane ,Molecular Biology - Abstract
FliP is a rare bacterial polytopic membrane protein synthesized with a cleavable highly hydrophobic signal peptide. It is essential for flagellum assembly and for bacterial motility. In this study, we assessed specificity of signal peptide for the FliP function. Like the wild type FliP, two altered FliPs with more hydrophilic Tat- or Sec-dependent signal peptides were both able to restore the motility of the ΔfliP mutant. Therefore, the Tat- and the Sec-dependent signal peptides seemed to be compatible with the FliP function. Moreover, deletion of the FliP signal peptide or replacing it with the transmembrane segment of MotA severely impaired the FliP function. Together these results showed that a cleavable signal peptide is required for the full function of FliP.
- Published
- 2004
10. Putative membrane assembly of EtpM-colicin V chimeras
- Author
-
Ross E. Dalbey, Nathalie Pradel, Changyun Ye, Long-Fei Wu, Liang Yi, Fabien Gérard, Bérengère Ize, Jianguo Xu, Laboratoire de chimie bactérienne (LCB), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Signal peptide ,Cytoplasm ,Protein Folding ,animal structures ,Recombinant Fusion Proteins ,Amino Acid Motifs ,Mutant ,Colicins ,Biology ,Arginine ,Escherichia coli O157 ,Biochemistry ,Twin-arginine translocation pathway ,Thermosensing ,[SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,Integral membrane protein ,Escherichia coli Proteins ,Cell Membrane ,Membrane Transport Proteins ,[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,Intracellular Membranes ,General Medicine ,Periplasmic space ,[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,Cell biology ,Cold Temperature ,Protein Transport ,Phenotype ,Secretory protein ,Membrane protein ,Colicin ,Gene Products, tat ,Mutation ,Periplasm ,embryonic structures - Abstract
EtpM of the enterohemorrhagic E. coli O157:H7 is a bitopic membrane protein of the type II protein secretion apparatus. There is a twin-arginine (RR) motif in front of its signal anchor, suggesting a Tat-dependent membrane targeting of EtpM. By exploiting the periplasmic bactericidal activity of colicin V (ColV), we constructed EtpM-ColV fusions and studied the EtpM-mediated translocation of ColV. The wild type strain and the Δ tatC mutant were killed by the expressed fusions and were fully protected from the killing effect by the ColV-specific immunity protein. In contrast, cold-inactivation of YidC, which is generally required for integral membrane protein assembly, significantly attenuated the killing effect in the cold-sensitive yidC mutant. These results confirmed the predicted N(in)-C(out) EtpM topology, and suggests an EtpM-mediated, Tat-independent and YidC-dependent translocation of ColV.
- Published
- 2004
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.