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Jiang Tao

Publications and source records attributed to Jiang Tao.

13 recordsLinked to original sources
PubMed2005

Simultaneous infection with dengue 2 and 3 viruses in a Chinese patient return from Sri Lanka.

Dengue is an acute viral disease transmitted by the Aedes aegypti and Aedes albopictus mosquito, which are present in most tropical urban areas of the world. There are four antigenically distinct serotypes, designated dengue-1 (DEN-1), dengue-2 (DEN-2), dengue-3 (DEN-3) and dengue-4 (DEN-4). Dengue outbreaks have occurred in several regions in Asia, involving four serotypes of dengue 1, 2, 3 and 4. In review of the few cases of dual infection documented in the literature, we report here a case of simultaneous infection with DEN-2 and DEN-3 in a Chinese patient return from Sri Lanka. The dual infection was identified by type-specific indirect immunofluorescence assay and confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) and sequence determination. This is the first documented case of simultaneous infection with serotype of DEN-2 and DEN-3 in China.

Adult↗
PubMed2005

A molecular-capsular-type prediction system for 90 Streptococcus pneumoniae serotypes using partial cpsA-cpsB sequencing and wzy- or wzx-specific PCR.

In a previous study, a molecular capsular type (MCT) prediction system for 51 Streptococcus pneumoniae serotypes was developed based on a combination of partial cpsA-cpsB sequencing and serotype(s)/group(s)-specific PCR. In this study, another 169 S. pneumoniae isolates were added to the existing database of 427 isolates, including representatives of all 39 serotypes not previously studied. In addition to the authors' own limited sequence data for all 90 serotypes, cpsA-cpsB sequence data published by the S. pneumoniae capsular loci-sequencing group (http://www.sanger.ac.uk/Projects/S_pneumoniae/CPS/) at the Sanger Institute or available from GenBank were incorporated into the database. All serotypes, except 25A, were represented by at least two isolates. The number of sequence types identified was 138, of which 110 corresponded to single conventional serotypes (CSs); of these, 57 were represented by two or more isolates. Twenty-six sequence types were shared by between two and four CSs. To resolve these shared cpsA-cpsB sequence types and increase the discriminatory power of our system, the genes encoding the capsular polysaccharide flippase (wzx) and polymerase (wzy) were annotated and 24 new serotype(s)/group(s)-specific PCRs targeting wzy and two targeting wzx were designed. Using both cpsA-cpsB sequencing and wzx/wzy PCR, MCT correctly predicted the CSs of 516 (73 %) and the serogroup of an additional 155 (22 %) of the 708 isolates evaluated. For 5 % of isolates, MCT could not distinguish between members of five serotype pairs (37 isolates) containing members of different serogroups. Although further study of the relationship between MCT and CS is needed, this system now allows serotype or serogroup identification of 95 % of S. pneumoniae isolates.

Bacterial Capsules↗
PubMed2005

Structural and genetic characterization of enterohemorrhagic Escherichia coli O145 O antigen and development of an O145 serogroup-specific PCR assay.

Enterohemorrhagic Escherichia coli O145 strains are emerging as causes of hemorrhagic colitis and hemolytic uremic syndrome. In this study, we present the structure of the E. coli O145 O antigen and the sequence of its gene cluster. The O145 antigen has repeat units containing three monosaccharide residues: 2-acetamido-2-deoxy-D-glucose (GlcNAc), 2-acetamidoylamino-2,6-dideoxy-L-galactose, and N-acetylneuraminic acid. It is very closely related to Salmonella enterica serovar Touera and S. enterica subsp. arizonae O21 antigen. The E. coli O145 gene cluster is located between the JUMPStart sequence and the gnd gene and consists of 15 open reading frames. Putative genes for the synthesis of the O-antigen constituents, for sugar transferase, and for O-antigen processing were annotated based on sequence similarities and the presence of conserved regions. The putative genes located in the E. coli O145 O-antigen gene cluster accounted for all functions expected for synthesis of the structure. An E. coli O145 serogroup-specific PCR assay based on the genes wzx and wzy was also developed by screening E. coli and Shigella isolates of different serotypes.

Amino Sugars↗
PubMed2005

Sequence analysis of the Escherichia coli O15 antigen gene cluster and development of a PCR assay for rapid detection of intestinal and extraintestinal pathogenic E. coli O15 strains.

A collection of 33 Escherichia coli serogroup O15 strains was studied with regard to O:H serotypes and virulence markers and for detection of the O-antigen-specific genes wzx and wzy. The strains were from nine different countries, originated from healthy or diseased humans and animals and from food, and were isolated between 1941 and 2003. On the basis of virulence markers and clinical data the strains could be split into different pathogroups, such as uropathogenic E. coli, enteropathogenic E. coli, Shiga toxin-producing E. coli, and enteroaggregative E. coli. H serotyping and genotyping of the flagellin (fliC) gene revealed 11 different H types and a close association between certain H types, virulence markers, and pathogroups was found. Nucleotide sequence analysis of the O-antigen gene cluster revealed putative genes for biosynthesis of O15 antigen. PCR assays were developed for sensitive and specific detection of the O15-antigen-specific genes wzx and wzy. The high pathotype diversity found in the collection of 33 O15 strains contrasted with the high level of similarity found in the genes specific to the O15 antigen. This might indicate that the O15 determinant has been spread by horizontal gene transfer to a number of genetically unrelated strains of E. coli.

Escherichia coli↗
PubMed2005

Molecular analysis of Shigella boydii O1 O-antigen gene cluster and its PCR typing.

Shigella is an important human pathogen and is closely related to Escherichia coli. O-antigen is the most variable part of the lipopolysaccharide on the cell surface of Gram-negative bacteria and plays an important role in pathogenicity. The O-antigen gene cluster of S. boydii O1 was sequenced. The putative genes encoding enzymes for rhamnose synthesis, transferases, O-unit flippase, and O-unit polymerase were identified on the basis of homology. The O-antigen gene clusters of S. boydii O1 and E. coli O149, which share the same O-antigen form, were found to have the same genes and organization by adjacent gene PCR assay. Two genes specific for S. boydii O1 and E. coli O149 were identified by PCR screening against E. coli- and Shigella-type strains of the 186 known O-antigen forms and 39 E. coli clinical isolates. A PCR sensitivity of 103 to 104 CFU/mL overnight culture of S. boydii O1 and E. coli O149 was obtained. S. boydii O1 and E. coli O149 were differentiated by PCR using lacZ- and cadA-based primers.

Bacterial Typing Techniques↗
PubMed2004

BOD: a customizable bioinformatics on demand system accommodating multiple steps and parallel tasks.

The integration of bioinformatics resources worldwide is one of the major concerns of the biological community. We herein established the BOD (Bioinformatics on demand) system to use Grid computing technology to set up a virtual workbench via a web-based platform, to assist researchers performing customized comprehensive bioinformatics work. Users will be able to submit entire search queries and computation requests, e.g. from DNA assembly to gene prediction and finally protein folding, from their own office using the BOD end-user web interface. The BOD web portal parses the user's job requests into steps, each of which may contain multiple tasks in parallel. The BOD task scheduler takes an entire task, or splits it into multiple subtasks, and dispatches the task or subtasks proportionally to computation node(s) associated with the BOD portal server. A node may further split and distribute an assigned task to its sub-nodes using a similar strategy. In the end, the BOD portal server receives and collates all results and returns them to the user. BOD uses a pipeline model to describe the user's submitted data and stores the job requests/status/results in a relational database. In addition, an XML criterion is established to capture task computation program details.

Computational Biology↗
PubMed2004

The O-antigen gene cluster of Shigella boydii O11 and functional identification of its wzy gene.

Shigella strains are human pathogens and their identification is usually based on their O-antigens. The O-antigen gene cluster of Shigella boydii O11 was sequenced. All the expected genes for the synthesis of the O-antigen were identified on the basis of homology and genes for the biosynthesis of dTDP-l-Rhamnose, genes encoding sugar transferases, as well as genes encoding O unit flippase (wzx) and O-antigen polymerase (wzy). The identity of the putative wzy gene was confirmed by showing that a wzy deficient mutant strain of S. boydii O11 produced a semi-rough LPS phenotype. The predicted wzx gene has an opposite transcription direction to that of all of the other genes in the S. boydii O11 O-antigen gene cluster. This unusual feature for the wzx gene has only previously been reported in S. boydii O6. Further comparison revealed an evolutionary relationship between O6 and O11 O-antigen gene clusters. Adjacent-gene PCR showed that Escherichia coli O105 and S. boydii O11, which share the identical O-antigen, also have the same genes and organization for their respective O-antigen gene clusters. Three genes specific for the S. boydii O11 and E. coli O105 gene clusters were identified.

Bacterial Proteins↗
PubMed2004

Structure of the Shigella dysenteriae 7 O antigen gene cluster and identification of its antigen specific genes.

Shigella strains are human pathogens. The O antigen gene cluster of Shigella dysenteriae O7 was sequenced and analyzed. It contains genes for synthesis of nucleotide sugars including UDP-2-acetamido-2-deoxy-D-galacturonamide, UDP-2-acetamido-2-deoxy-D-galacturonic acid and dTDP-4-amino-4,6-dideoxy-D-glucose. Also found in the gene cluster are genes encoding O unit flippase, O antigen polymerase and sugar transferases. The Escherichia coli O121 O antigen, which is present in an important Shiga toxin-producing strain, has the same structure as that of S. dysenteriae O7, and we found that the gene clusters also had the same genes and organization. Four genes specific to S. dysenteriae O7 and E. coli O121 were identified by PCR screening against representatives of 186 E. coli (including Shigella) O serotypes. E. coli O121 and S. dysenteriae O7 isolates can be distinguished by PCR of the H antigen fliC gene.

Carrier Proteins↗
PubMed2004

Synthesis of the heteropolysaccharide O antigen of Escherichia coli O52 requires an ABC transporter: structural and genetic evidence.

The structural and genetic organization of the Escherichia coli O52 O antigen was studied. As identified by sugar and methylation analysis and nuclear magnetic resonance spectroscopy, the O antigen of E. coli O52 has a partially O-acetylated disaccharide repeating unit (O unit) containing D-fucofuranose and 6-deoxy-D-manno-heptopyranose, as well as a minor 6-deoxy-3-O-methylhexose (most likely, 3-O-methylfucose). The O-antigen gene cluster of E. coli O52, which is located between the galF and gnd genes, was found to contain putative genes for the synthesis of the O-antigen constituents, sugar transferase genes, and ABC-2 transporter genes. Further analysis confirmed that O52 employs an ATP-binding cassette (ABC) transporter-dependent pathway for translocation and polymerization of the O unit. This is the first report of an ABC transporter being involved in translocation of a heteropolysaccharide O antigen in E. coli. Genes specific for E. coli O52 were also identified.

ATP-Binding Cassette Transporters↗
PubMed2004

Structural and genetic characterization of the Shigella boydii type 13 O antigen.

Shigella is an important human pathogen. It is generally agreed that Shigella and Escherichia coli constitute a single species; the only exception is Shigella boydii type 13, which is more distantly related to E. coli and other Shigella forms and seems to represent another species. This gives S. boydii type 13 an important status in evolution. O antigen is the polysaccharide part of the lipopolysaccharide in the outer membrane of gram-negative bacteria and plays an important role in pathogenicity. The chemical structure and genetic organization of the S. boydii type 13 O antigen were investigated. The O polysaccharide was found to be acid labile owing to the presence of a glycosyl phosphate linkage in the main chain. The structure of the linear pentasaccharide phosphate repeating unit (O unit) was established by nuclear magnetic resonance spectroscopy, including two-dimensional COSY, TOCSY, ROESY, and H-detected 1H, 13C and 1H, 31P HMQC experiments, along with chemical methods. The O antigen gene cluster of S. boydii type 13 was located and sequenced. Genes for synthesis of UDP-2-acetamido-2,6-dideoxy-L-glucose and genes that encode putative sugar transferases, O unit flippase, and O antigen polymerase were identified. Seven genes were found to be specific to S. boydii type 13. The S. boydii type 13 O antigen gene cluster has higher levels of sequence similarity with Vibrio cholerae gene clusters and may be evolutionarily related to these gene clusters.

Carbohydrates↗
PubMed2004

Identification of Escherichia coli O114 O-antigen gene cluster and development of an O114 serogroup-specific PCR assay.

Screening for the Escherichia coli O serotype is the traditional test for identification of E. coli clones. The O-antigen gene cluster of the E. coli O114 type strain was sequenced, and 12 open reading frames were assigned functions on the basis of homology. By screening against all 186 E. coli and Shigella O serotypes, five genes specific to E. coli O114 were identified. A PCR assay based on the O-antigen-specific genes was developed and tested on 41 clinical isolates of E. coli O114. The PCR assay was shown to be highly specific and sensitive. When tested with pork and water samples, as few as 0.12 CFU of E. coli O114 g(-1) were detected. Thus, the PCR assays established in this study can be used to reliably identify E. coli O114 strains and may also be used to detect E. coli O114 strains in food, water, and other environmental samples.

Base Sequence↗
PubMed2003

[Preliminary analysis of gene expression profiles in oral cancer with microarray technique].

OBJECTIVE: To study the difference in gene expression between oral squamous cell carcinoma tissue and their surrounding normal tissue by microarray so as to investigate the preliminary mechanism of pathogenesis of oral cancer. METHODS: The tissues from 5 patients with oral squamous cell carcinoma tissue and their surrounding normal tissue from the same patients were analyzed by cDNA microarray technology(including 4124 genes). Total RNAs were isolated from two tissues, and then were reversely transcribed to cDNAs with the incorporations of fluorescent dUTP,for preparing the hybridization probes. The mixed probes were then hybridized to the cDNA microarray. After high-stringent washing, the cDNA microarray was scanned for the fluorescent signals and showed the differences between the two tissues. Bioinformatical analysis of those genes had been performed. RESULTS: Among the 4124 target genes, there were 37(0.89%)genes whose expression levels differed between the carcinoma and their surrounding normal tissues in all 5 cases. Bioinformatical analysis of those genes suggested that they may be related to the multistep process of carcinogenesis. CONCLUSION: cDNA microarray technique can simultaneously screen the different expressions of genes from 2 different kinds of tissue. Further analysis of the obtained genes will help to understand the molecular mechanism of malignant carcinoma.

Aged↗