Twenty-four monoclonal antibodies were produced by immunizing BALB/c mice with Rickettsia tsutsugamushi Boryong strain and used for the analysis of antigenic characteristics of R.tsutsugamushi Boryong strain and antigenic heterogeneity of R.tsutsugamushi by indirect immunofluorescent(IF) test. R. tsutsugamushi Kato, Karp, Gilliam, TA686, TA716, TA763, TC586, TH1817, and Boryong were used for the analysis of antigenic heterogeneity of R.tsutsugamushi. Five monoclonal antibodies were reactive with 27-kDa protein, four monoclonal antibodies were reactive with 47-kDa protein, and eight monoclonal antibodies were reactive with 56-kDa protein of R.tsutsugamushi Boryong strain. The reactive protein of seven monoclonal antibodies could not be identified by immunoblotting method. All monoclonal antibodies to 27-kDa protein and three monoclonal antibodies to 47-kDa protein, and five monoclonal antibodies to 56-kDa protein were reactive with three to eight strains among nine strains of R. tsutsugamushi tested. One monoclonal antibody reactive to 47-kDa protein(KI18) and two monoclonal antibodies reactive to 56-kDa protein(KI36, and KI37) reacted with all the strains of R. tsutsugamushi tested. Strain-specific monoclonal antibody(KI58) could be found among antibodies which were reactive with 56-kDa protein. There was no strain which showed same reactivity pattern to these 24 monoclonal antibodies among nine strains. From this results, it could be concluded that Boryong strain is antigenically different from other strains of R.tsutsugamushi and antigenic heterogeneity of R.tsutsugamushi is due to the antigenic diversity of several proteins of R. tsutsugamushi including 56-kDa protein.
Animals ; Antibodies, Monoclonal/*immunology ; Antigens, Bacterial/*analysis ; Bacterial Proteins/analysis ; Mice ; Mice, Inbred BALB C ; Orientia tsutsugamushi/*immunology ; Species Specificity

Streptomyces coelicolor is the model species among streptomycetes. Until now, proteomic analyses of S. coelicolor have been conducted using two-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, few integral membrane proteins were identified due to the hydrophobic and low-abundance nature of these proteins. In this work, 154 possible inner membrane proteins from S. coelicolor were identified using high pH-proteinase K sample preparation method and multidimensional protein identification technology, among them 44 are integral membrane proteins containing at least one transmembrane domain, most peptides and their corresponding proteins were identified experimentally for the first time.
Bacterial Proteins ; analysis ; Cell Membrane ; chemistry ; Genome, Bacterial ; genetics ; Mass Spectrometry ; methods ; Membrane Proteins ; analysis ; Proteome ; analysis ; genetics ; Streptomyces coelicolor ; chemistry ; genetics

OBJECTIVETo explore the application of biosensor technology in the determination of endotoxin-neutralizing materials.

METHODSAfter mixing polymyxin B (PMB) with endotoxin in certain concentration, the neutralizing ratio of PMB to endotoxin was assessed by biosensor technique and limulus amebocyte lysate test respectively. The results from the two methods were compared.

RESULTSThe neutralizing ratio of PMB to endotoxin as assessed by biosensor technology was 0.35 microg to 1 ng, while that by dynamic turbidimetric and chromogenic limulus amebocyte lysate (LAL) technique was 0.5 mg to 1 ng and 1 mg to 1 ng, respectively. The results obtained by biotechnology were similar to that by biosensor technique.

CONCLUSIONBiosensor technology was an accurate, convenient and rapid method for the determination of potency of endotoxin-neutralizing materials.

Bacterial Proteins ; analysis ; Biosensing Techniques ; methods ; Endotoxins ; analysis ; Lipid A ; analysis ; Polymyxin B ; analysis ; Reproducibility of Results ; Sensitivity and Specificity

Bacterial Proteins ; analysis ; China ; Proteome ; analysis ; Proteomics ; Yersinia pestis ; chemistry ; genetics

OBJECTIVETo analyze the genetic differences of Orientia tsutsugamushi (Ot) Sta56 gene between Shandong isolates and other strains deposited in GenBank.

METHODSPCR and restriction fragment length polymorphism (RFLP) were used to amplify the complete sequence of Ot-Sta56 gene. RFLP profiles of Ot were predicted by a computer program according to their complete sequences of Ot-Sta56 gene. PCR amplicon from XDM2 strain was sequenced and analyzed by Clustal X (1.8) and PHYLIP software.

RESULTSThe complete sequences (about 1.6 kbp) of Ot-Sta56 gene were amplified from B16 strain (isolated from patients), FXS2 strain (isolated from A. agrarius) and XDM2 strain. Four species of restriction endonucleases (Hha I, Hinf I, Hae III, Pst I) were used to digest the PCR amplicons from the 3 isolates. When comparing with the RFLP profiles of prototype Ot, the RFLP profiles of PCR amplicons from the 3 isolates were similar to those of Japan Kawasaki strain, but were quite different from the international reference strains Gilliam, Karp, Kato. Results from DNA sequence analysis showed that the complete sequence of Ot-Sta56 gene homology to Japan Kawasaki strain of XDM2 strain was 97%, and deduced amino acid sequence was 92%.

CONCLUSIONData from the complete sequence of Sta56 gene indicated that the genotypes of Ot isolates in Shandong province were similar, but with distinction from the Kawasaki strain.

Amplified Fragment Length Polymorphism Analysis ; Antigens, Bacterial ; genetics ; Bacterial Proteins ; genetics ; Bacterial Typing Techniques ; classification ; DNA, Bacterial ; genetics ; Genes, Bacterial ; Membrane Proteins ; genetics ; Orientia tsutsugamushi ; genetics ; isolation & purification ; Polymorphism, Restriction Fragment Length ; Sequence Analysis, DNA

OBJECTIVETo construct a rapid and high-throughput assay for identifying recombinant bacteria based on mass spectrometry.

METHODSMatrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques were used to identify 12 recombinant proteins (10 of Yersinia pestis, 1 of Campylobacter jejuni and 1 of Helicobacter pylori). A classification model for the various phase of recombinant bacteria was established, optimized and validated, using MALDI-TOF MS-ClinProTools system. The differences in the peptide mass spectra were analyzed by using Biotyper and FlexAnalysis softwares.

RESULTSModels of GA, SNN, and QC were established. After optimizing the parameters, the GA recognition model showed good classification capabilities: RC=100%, mean CVA=98.7% (the CVA was 96.4% in phase 1, 100% in phase 2, 98.4% in phase 3, and 100% in phase 4, respectively) and PPV=95%. This model can be used to classify the bacteria and their recombinant, which only requires 3.7×103 cells for analysis. The total time needed is only 10 min from protein extraction to reporting the result for one sample. Furthermore, this assay can automatically detect and test 96 samples concurrently. A total of 48 specific peaks (9, 16, 9, and 14 for the four stages, respectively) was found in the various phase of recombinant bacteria.

CONCLUSIONMALDI-TOF MS can be used as a fast, accurate, and high-throughput method to identify recombinant bacteria, which provide a new ideas not only for recombinant bacteria but also for the identification of mutant strains and bioterrorism pathogens.

Bacterial Proteins ; analysis ; Cloning, Molecular ; Escherichia coli ; Mass Spectrometry ; Organisms, Genetically Modified ; Peptide Mapping ; Recombinant Proteins ; analysis

OBJECTIVEIn this study, we evaluated the diagnostic efficiency of six recombinant proteins for the serodiagnosis of Lyme borreliosis (LB) and screened out the appropriate antigens to support the production of a Chinese clinical ELISA (enzyme-linked immunosorbent assay) kit for LB.

METHODSSix recombinant antigens, Fla B.g, OspC B.a, OspC B.g, P39 B.g, P83 B.g, and VlsE B.a, were used for ELISA to detect serum antibodies in LB, syphilis, and healthy controls. The ELISA results were used to generate receiver operating characteristic (ROC) curves, and the sensitivity and specificity of each protein was evaluated. All recombinant proteins were evaluated and screened by using logistic regression models.

RESULTSTwo IgG (VlsE and OspC B.g) and two IgM (OspC B.g and OspC B.a) antigens were left by the logistic regression model screened. VlsE had the highest specificity for syphilis samples in the IgG test (87.7%, P<0.05). OspC B.g had the highest diagnostic value in the IgM test (AUC=0.871). Interactive effects between OspC B.a and Fla B.g could reduce the specificity of the ELISA.

CONCLUSIONThree recombinant antigens, OspC B.g, OspC B.a, and VlsE B.a, were useful for ELISAs of LB. Additionally, the interaction between OspC B.a and Fla B.g should be examined in future research.

Antigens, Bacterial ; blood ; Bacterial Proteins ; analysis ; China ; Enzyme-Linked Immunosorbent Assay ; veterinary ; Lyme Disease ; diagnosis ; Recombinant Proteins ; analysis ; Sensitivity and Specificity ; Serologic Tests ; veterinary

OBJECTIVETo investigate the drug resistance of flavobacterium and its ability to produce BLA (beta-lactamases) and ESBLs (Extended-spectrum beta-lactamases).

METHODSThe production of BLA and ESBLs from 6 clinical isolated flavobacterium strains was determined by nitrocefin disc test and double-disc synergy method, respectively. The antibiotic susceptibilities of the strains were determined by Kirby-Bauer disc diffusion test and the agar dilution method and the MIC was assessed.

RESULTSAll the six flavobacteria were BLA-producing strains and more than 80% of them were ESBLs-producing, and they were highly resistant to beta-lactamase antibiotics (MIC 32 - 256 mg/L), but susceptible to fluoroquinolones and cephalosporin with beta-lactamase inhibitors (MIC 0.125 - 8 mg/L).

CONCLUSIONMost of the flavobacteria in nosocomial infections were beta-lactamase-producing and were highly resistant to beta-lactamase antibiotics. Fluoroquinolones and beta-lactamase antibiotics with lactamase inhibitors should be the first choice for the management of infection caused by flavobacterium.

Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Bacterial ; drug effects ; Flavobacterium ; drug effects ; enzymology ; Humans ; Membrane Proteins ; analysis ; metabolism ; Microbial Sensitivity Tests ; Ribosomal Proteins ; analysis ; metabolism

OBJECTIVETo investigate the expression and analysis of its activity of anti-bacterial peptide gloverin in COS-7 cells.

METHODSThe appearance frequency of all genetic codes in the cDNA sequence from the same species of protein Attacin A was analyzed, and its cDNA sequence was synthesized by PCR overlapping extension method in conjunction with the designation of the known protein sequence of gloverin. The genes were inserted into pCDSI, an eukaryotic vector, after being identified correctly. As a result, the vector pBZHG was constructed. Thereafter, the liposome FuGENE( trade mark ) 6 was employed as the vector, and the COS-7 cells were transfected with liposome pBZHG and blank vector pCDSI. The normal cells were taken as the control. The supernatant was collected for the detection of its bactericidal activity after 72 PBHs.

RESULTSThe gloverin cDNA sequence designed artificially was expressed in COS-7 cells. The supernatant of the cells transfected by pBZHG exhibited bactericidal activity to E. coli J5 when compared with that from normal cells and in cells transfected with blank vectors.

CONCLUSIONThe designed cDNA sequence of gloverin was proved to be genuine, and it provided the basis for future study of its antibiotic and anti-endotoxin activities.

Animals ; Anti-Bacterial Agents ; pharmacology ; COS Cells ; Cercopithecus aethiops ; Proteins ; genetics ; pharmacology ; Sequence Analysis, DNA ; Transfection

OBJECTIVETo determine the sequence of the active peptide derived from recombinant hemagglutinin (rHA-2) of Porphyromonas gingivalis (Pg).

METHODSThe HA-2 gene from PgATCC33277 was cloned, expressed in Escherichia coli (Ec) BL21 (DE3), and purified. The purified recombinant protein was evaluated for its ability to bind hemin-linked agarose. The active peptide was subjected to endoproteinase-mediated sequence analysis.

RESULTSThe protein expressed in Ec BL21 (DE3) was identified as PgHA-2 by plasmid sequence analysis, Western blotting, and mass spectrometry. The recombinant protein was confirmed functional by its ability to bind hemin. The sequence of the active peptide of rHA-2 was determined to be DHYAVMISKTGTNAG.

CONCLUSIONSThe availability of sequence of the active peptide of rHA-2 provides a foundation for the development of immunoprophylactic and therapeutic agents against this human pathogen.

Bacterial Proteins ; chemistry ; genetics ; Hemagglutinins ; chemistry ; genetics ; Porphyromonas gingivalis ; genetics ; Sequence Analysis, Protein