Protection elicited by a replication-defective adenovirus vector expressing the tick-borne encephalitis virus non-structural glycoprotein NS1.

Tick-borne encephalitis virus (TBEV) encodes a conserved, immunogenic, non-structural protein NS1 that is glycosylated and secreted from infected cells in an oligomeric form. An adenovirus recombinant, RAd51, expressing high levels of TBEV NS1 has previously been demonstrated to protect mice against a lethal challenge with TBEV. We show here that BALB/c mice infected with TBEV experienced a transient viraemia between days 3 to 5 post-inoculation that was detectable prior to the encephalitic phase of infection.

Microbial ecology of dental plaque and its significance in health and disease.

Dental plaque forms naturally on teeth and is of benefit to the host by helping to prevent colonization by exogenous species. The bacterial composition of plaque remains relatively stable despite regular exposure to minor environmental perturbations. This stability (microbial homeostasis) is due in part to a dynamic balance of both synergistic and antagonistic microbial interactions.

The functional units of a peptostreptococcal protein L.

Protein L is a cell-surface protein from Peptostreptococcus which interacts with immunoglobulin kappa light chains. A gene from Peptostreptococcus strain 3316 coding for protein L and fragments thereof were expressed in Escherichia coli. The peptides were examined for binding to immunoglobulin and serum albumin.

The effect of growth rate and haemin on the virulence and proteolytic activity of Porphyromonas gingivalis W50.

Porphyromonas gingivalis strain W50 was grown under haemin-limitation and haemin-excess conditions in a chemostat at pH 7.5. The maximum specific growth rate (mumax) was determined at both haemin concentrations (mumax = 0.

An investigation of the thermal stabilities of two malate dehydrogenases by comparison of their three-dimensional structures.

The tertiary structure of Thermus aquaticus malate dehydrogenase (MDH) was predicted based on the known crystal structure of pig heart cytosolic MDH. Guanidinium chloride (GdmCl) unfolding experiments showed that there is only about a 4.2-kjoule/mol difference in delta G 0 between the pig and Thermus MDH.

Characterization of phosphoinositol oligosaccharides from parasitic protozoa by fast atom bombardment and collisional activation mass spectrometry.

Fast atom bombardment mass spectrometry (FAB MS) enables the rapid, accurate and sensitive determination of the molecular masses of glycosylphosphatidylinositol (GPI)-derived oligosaccharides, from which the composition in terms of monosaccharide residues and non-carbohydrate substituents can be determined. Interpretation of fragment ions in collisional activation mass spectra further enables the determination of residue sequence, the positions of branch points, and the location of non-carbohydrate substituents. We have applied these techniques to the characterization of phosphoinositol oligosaccharides from Leptomonas samueli, Endotrypanum schaudinni and Leishmania adleri.

Nucleotide sequence of the gene for peptostreptococcal protein L.

A gene bank of Peptostreptococcus magnus DNA was established using an E. coli host-vector system. Western blot analysis identified a clone expressing protein L which bound to the light chain of human immunoglobulins.

The development and assessment of DNA and oligonucleotide probes for the specific detection of Bacillus anthracis.

Two DNA probes and a number of oligonucleotide probes were designed from the virulence factor genes of Bacillus anthracis. These probes were tested for specificity against 52 B. anthracis strains and 233 Bacillus strains encompassing 23 other species.

Demonstration of lipooligosaccharide immunotype and capsule as virulence factors for Neisseria meningitidis using an infant mouse intranasal infection model.

Using an infant mouse intranasal infection model, we have compared the virulence of 17 epidemiologically related isolates of Neisseria meningitidis associated with an outbreak of meningococcal disease in Gloucestershire, UK, and one German isolate. The isolates were all of serotype 15 subtype P1:7, 16 and were identical by restriction fragment length polymorphism analysis, but differed in either (i) whether they were isolated from a case or a carrier, (ii) the presence or absence of group B capsule, or (iii) their lipooligosaccharide (LOS) immunotype. The results indicate that capsule is a major virulence determinant and is required for colonization and hence for invasion.

Detection of Legionella pneumophila in biofilms containing a complex microbial consortium by gas chromatography-mass spectrometry analysis of genus-specific hydroxy fatty acids.

A gas chromatographic-mass spectrometric method was used to detect Legionella pneumophila in biofilms in potable water containing a complex microbial consortium. The unique 3-hydroxy and 2,3-dihydroxy fatty acids of the L. pneumophila lipopolysaccharides (LPS) were detected in both the planktonic phase of the continuous culture model and in the biofilms forming on both copper and polyethylene substrata.

Cloning and sequence analysis of the genes encoding phosphotransbutyrylase and butyrate kinase from Clostridium acetobutylicum NCIMB 8052.

An 8.1-kb fragment of chromosomal DNA from Clostridium acetobutylicum NCIMB 8052 (formerly NCIB 8052) has been cloned into plasmid pAT153 and shown to allow the growth of Escherichia coli LJ32 (F+ atoC2c atoD32 fadR) on butyrate as the sole source of carbon and energy. Deletion analysis delineated a 3.

Microbiological effects of new agents in dentifrices for plaque control.

The incorporation of antimicrobial agents in dental products has been proposed for many years as a possible valuable adjunct to mechanical plaque control. Out of the diverse collection of potential agents, relatively few can be formulated into dentifrices. Several products have been developed based on Triclosan, a broad spectrum antimicrobial agent.

Measles virus nucleocapsid protein expressed in insect cells assembles into nucleocapsid-like structures.

The gene encoding the major nucleocapsid, N, protein of measles virus has been inserted into a baculovirus vector under the control of the polyhedrin promoter. Insect cells infected with this recombinant baculovirus synthesize high levels of measles N protein, up to 40% of total soluble cell protein. The recombinant protein is recognized by sera from convalescent patients, vaccinees and patients with subacute sclerosing panencephalitis and thus could form the basis of a simple diagnostic assay.

Preparation of DNA polymerase from Bacillus caldotenax.

A procedure with four chromatography steps was developed for the purification of DNA polymerase from Bacillus caldotenax by using fast protein liquid chromatography. The procedure was suitable for use with process-scale media. Elution profiles obtained from ion-exchange chromatography and triazine-dye affinity chromatography with fast protein liquid chromatography and process-scale media were similar.

The complete amino acid sequence of a hirudin variant from the leech Hirudinaria manillensis.

Unlike the European leech Hirudo medicinalis, the Asian jawed leech Hirudinaria manillensis is specialized for feeding on mammalian blood. In the salivary glands of both these leeches, there is a potent inhibitor of thrombin, called hirudin, which acts as an anticoagulant. We have reported previously the isolation and purification of a variant of hirudin, called bufrudin, from the head portions of Hirudinaria.

The membrane binding C-terminus of protein A from Staphylococcus aureus affects its cellular localization and causes structural deformation when expressed in Escherichia coli.

Protein A from Staphylococcus aureus is a powerful diagnostic reagent and has several uses in human disease therapy. Expression in non-pathogenic Escherichia coli containing recombinant plasmids coding for this protein has increased its availability, but can reduce the stability of the plasmid-bearing host. By employing immune electron microscopy, we have determined that E.

Comparison of serum antibody reactivities to a conformational and to linear antigenic sites in the external envelope glycoprotein of simian immunodeficiency virus (SIVmac) induced by infection and vaccination.

Forty-six overlapping peptides (20-mers) representing the amino acid sequence of the external envelope glycoprotein of simian immunodeficiency virus (SIVmac; 32H isolate) were used to investigate linear antigenic sites recognized by antibodies in sera from SIV-infected rhesus macaques and in animals vaccinated with formalin-inactivated SIV. The reactivity to a discontinuous antigenic site as defined by a neutralizing monoclonal antibody was measured by competition assay. The majority of infected macaques recognized three linear antigenic determinants within the V1, V3 and C5 regions of the external glycoprotein.

Molecular evolution of bacterial cell-surface proteins.

The cell-surface proteins of the infective bacteria Streptococcus and Staphylococcus are probably involved in the process of infection. These proteins share many features including secretion signal peptides, cell-wall spanning regions, membrane anchor domains and repeated domains of various functions. These common features may have evolved by gene duplication and swapping of gene fragments.

The effect of the olive phenolic compound, oleuropein, on growth and enterotoxin B production by Staphylococcus aureus.

The presence of low concentrations (0.1% w/v) of oleuropein, a phenolic compound extracted from olives, delayed the growth of Staphylococcus aureus in NZ amine A and brain heart infusion media modified by the addition of growth factors and glucose (NZA+ and BHI+), as indicated by changes in conductance, whilst higher concentrations (0.4-0.

Optimisation of small-scale coupling of A5B7 monoclonal antibody to carboxypeptidase G2.

Conjugates of F(ab')2 fragment of the monoclonal antibody A5B7 coupled to carboxypeptidase G2 (CPG2) have been produced using the heterobifunctional reagents 2-mercapto-[S-acetyl]acetic acid, N-hydroxysuccinimide ester (SATA) and m-maleimidobenzoyl-N-hydroxysuccinimide ester (SMPB). The effect of various levels of modifying reagent on enzyme activity and antigen binding activity were determined, and it was shown that whilst CPG2 is relatively sensitive to modification, insertion of three maleimide groups per CPG2 resulted in the loss of 30% of enzyme activity; A5B7 F(ab')2 was insensitive to modification, little or no activity being lost. The coupling efficiency of the reaction was shown to be fairly constant over a wide range of substitution levels.

Antimicrobial strategies in the prevention of dental caries.

Antimicrobial agents, applied either professionally or delivered from dentifrices or mouthwashes, could reduce caries by controlling plaque formation, suppressing cariogenic species, or by inhibiting bacterial metabolism. Chlorhexidine has proven anticaries activity; other agents might also prevent caries by means of their antiplaque properties. Sugar substitutes stabilize the microflora by reducing the number of acid challenges to plaque and stimulating saliva flow; some also have antimicrobial properties, especially against mutans streptococci.

Sequence of the NS 1 gene of the K 23 isolate of tick-borne encephalitis virus and identification of conserved motifs.

The NS 1 gene from the K 23 isolate of tick-borne encephalitis virus has been sequenced. The NS 1 gene sequence, and many structural features of the NS 1 protein are heavily conserved. Six conserved peptides were also identified.

Adhesive and hydrophobic properties of Escherichia coli from the rectal mucosa of patients with ulcerative colitis.

The adherent properties and hydrophobicity of Escherichia coli isolates have been compared from the rectal mucosa of patients with active and inactive ulcerative colitis and from a control patient group. Patients with active colitis were colonised less frequently and with lower numbers of E coli than were control patients. Mannose resistant adhesion to HEp-2 cells was determined for 124 isolates of E coli and surface hydrophobicity was estimated by salt agglutination in 96 of these isolates.