Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MOUTH DISEASES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed2006

Evaluation of three 3ABC ELISAs for foot-and-mouth disease non-structural antibodies using latent class analysis.

BACKGROUND: Foot-and-mouth disease (FMD) is a highly contagious viral disease of even-toed ungulates. Serological diagnosis/surveillance of FMD presents several problems as there are seven serotypes worldwide and in the event of vaccination it may be necessary to be able to identify FMD infected/exposed animals irrespective of their vaccination status. The recent development of non-structural 3ABC protein (NSP) ELISA tests has greatly advanced sero-diagnosis/surveillance as these tests detect exposure to live virus for any of the seven serotypes of FMD, even in vaccinated populations. This paper analyses the performance of three NSP tests using a Bayesian formulation of the Hui-Walter latent class model to estimate test sensitivity and specificity in the absence of a "gold-standard" test, using sera from a well described cattle population in Cameroon with endemic FMD. RESULTS: The analysis found a high sensitivity and specificity for both the Danish C-ELISA and the World Organisation for Animal Health (O.I.E.) recommended South American I-ELISA. However, the commercial CHEKIT kit, though having high specificity, has very low sensitivity. The results of the study suggests that for NSP ELISAs, latent class models are a useful alternative to the traditional approach of evaluating diagnostic tests against a known "gold-standard" test as imperfections in the "gold-standard" may give biased test characteristics. CONCLUSION: This study demonstrates that when applied to naturally infected zebu cattle managed under extensive rangeland conditions, the FMD ELISAs may not give the same parameter estimates as those generated from experimental studies. The Bayesian approach allows for full posterior probabilities and capture of the uncertainty in the estimates. The implications of an imperfect specificity are important for the design and interpretation of sero-surveillance data and may result in excessive numbers of false positives in low prevalence situations unless a follow-up confirmatory test such as the enzyme linked immunoelectrotransfer blot (EITB) is used.

Aging↗
PubMed2005

Evolving perception on the benefits of vaccination as a foot and mouth disease control policy: contributions of South America.

Within the past decade, changes in perceptions on the benefits of vaccination as an appropriate tool to achieve complete foot and mouth disease eradication have become evident. The former negative view was derived from misconceptions, resulting mainly from the belief that vaccines are not entirely effective and that vaccination masks asymptomatic viral circulation. The advent in the 1990s of vaccination policies implemented within a strategic eradication plan in South America, and during recurrence of the disease in disease-free regions contributed towards generating more reliable and visible outcomes of vaccination programs, paving the way towards a new perception. Particularly relevant was the development and application of novel serodiagnostic approaches to assess silent viral circulation, irrespective of vaccination. The use in South America of vaccination allied to serosurveys to accompany viral clarification during eradication campaigns and after emergencies clearly established the importance of this control tool to stop the spread of viral infection. This alliance gave input to break many myths associated with the use of vaccines, including the belief that immunized carrier animals pose an epidemiologic risk. This experience launched new concepts that supported the internationally recognized status of foot and mouth disease-free regions with vaccination and the 'vaccination to live' policy as an alternative to 'stamping out'.

Animals↗
PubMed1979

Stability and immunogenicity of empty particles of foot-and-mouth disease virus.

Three strains of foot-and-mouth disease virus were shown to contain significant amounts of naturally occurring 75S, empty particles as well as the infectious, 140S full particles. One of these strains--A Pando (1970)--was studied in detail. The empty particles from this virus strain were shown to have an observed sedimentation coefficient of 67S in 0.04 M phosphate buffer; they were labile in SDS, non-infectious and probably RNA-free and, on heating, they broke down to 12S subunits as did the 140S particles. The empty particles differed from the full particles in their polypeptide composition since they contained VP0, but there was no evidence for a diminished content of VP4. The 75S particles were shown to be present in significant amounts and to be stable to AEI inactivation. At 4 degrees C they were stable for at least two years. In guinea pigs they were as immunogenic as the 140S particles. The antisera raised against the 75S particles had the same serological specificity in neutralization tests as sera prepared against the 140S particle. It was concluded that the 75S particles from the A Pando (1970) strain of FMD virus may provide as important a contribution as 140S particles to the immunogenicity of inactivated vaccines prepared from this virus strain.

Antigens, Viral↗
PubMed1994

Sequence of the S fragment of foot-and-mouth disease virus type A12.

The foot-and-mouth disease virus (FMDV) genome contains a 5' untranslated region (S fragment) capable of forming a stem-loop structure of over 350 bases, which is separated from the remainder of the genome by a homopolymeric cytidylic acid tract (poly(C)) of variable length. The sequence of the S fragment of serotype A12 appears more similar to those of type O1 or type C3 than to subtype A10. The relatively large difference between the S fragment sequences of two type A viruses suggests that the sequences per se of this region of the genome are not critical for the maintenance of function, and suggests the possibility of a relatively recent recombination event within the poly(C) region of the A12 genome.

Amino Acid Sequence↗
PubMed1969

The isolation of two enzyme-ribonucleic acid complexes involved in the synthesis of foot-and-mouth disease virus ribonucleic acid.

The foot-and-mouth disease virus-RNA polymerase complex was released from membrane particulates present in the cytoplasm of infected baby hamster kidney cells. The soluble polymerase complex was fractionated by zonal centrifugation in sucrose gradients. Two polymerase complexes (RNA and protein complex) active in the cell-free system were isolated and had S-rate ranges of 20-70S and 100-300S, respectively. The light polymerase complex contained 20S double-stranded RNA; and the heavy polymerase complex contained a polydisperse, partially RNase-resistant RNA. The cell-free product of these two polymerase complexes was analyzed by zonal centrifugation in sucrose gradients. The light polymerase complex synthesized only 20S double-stranded RNA. The product of the heavy polymerase complex contained no detectable 20S double-stranded RNA and only a peak of single-stranded RNA with S-rate corresponding to 37S viral RNA. A third polymerase complex was isolated with S-rate greater than 300S, and it contained a polydisperse, partially RNase-resistant RNA. This third polymerase complex synthesized both 37S viral RNA and 20S double-stranded RNA in the cell-free system, and it is probably the native polymerase complex still bound to cellular particulates.

Animals↗
PubMed1988

Studies on the infectivity of foot-and-mouth disease virus RNA using microinjection.

Foot-and-mouth disease virus (FMDV) RNA, isolated as virion RNA from purified virus particles or as total RNA from infected cells, has been microinjected into nuclei and cytoplasms of BHK cells. When injected directly into the nucleus FMDV RNA was not infectious, whereas cytoplasmic injection resulted in a high proportion of productive infections. Infectivity microinjection assays on dilution series of various FMDV RNAs showed that both single-stranded positive sense 35S RNA and double-stranded replicative form (Rf) RNA have an infectivity close to 1 p.f.u. per molecule, although only a minor fraction of BHK cells appeared able to support plaque formation following microinjection of Rf FMDV RNA. The infectivity of Rf FMDV RNA was not sensitive to inhibition by actinomycin D. The results are discussed in relation to the high virus particle to p.f.u. ratios observed for FMDV.

Animals↗
PubMed1993

Methods used in the structure determination of foot-and-mouth disease virus.

The structure of foot-and-mouth disease virus (FMDV) strain O1 BFS 1860 has been determined to 2.9 A resolution using the molecular-replacement method [Acharya, Fry, Stuart, Fox, Rowlands & Brown (1989). Nature (London), 337, 709-716]. Crystals of the virus with average dimensions 0.12 x 0.06 x 0.12 mm belong to space group I23, a = 345 A with 1/12 of the icosahedral particle per asymmetric unit giving fivefold noncrystallographic redundancy. Oscillation diffraction photographs were collected at the SERC Synchrotron Radiation Source at Daresbury in accordance with strict disease security regulations. The ambiguity in particle orientation was resolved using a self-rotation function and starting estimates of the phases to 8 A were derived from the known structures of two picornaviruses similarly oriented in the I23 unit cell. The phases were refined and extended using iterative averaging and solvent flattening with the implementation of a simple automatic envelope-determination procedure to increase the phasing power available.

Aphthovirus↗
PubMed1981

Identification of a protein kinase activity in purified foot- and-mouth disease virus.

Purified preparations of foot-and-mouth disease virus types A, O, and C contain a protein kinase activity which can transfer the gamma phosphate of [32P]ATP to virion structural proteins VP2 and VP3 and exogenous acceptor proteins. Utilizing protamine sulfate as an acceptor, the kinase activity can be demonstrated in disrupted virus but not in intact virus. The enzyme is heat labile with optimal activity at pH 7 or greater. Serine residues of protamine sulfate were identified as the amino acid phosphorylated by the protein kinase. Treatment of purified virus with trypsin, which cleaves VP3, did not affect the protein kinase activity. The results indicate that the protein kinase activity found in FMDV is present in an internally located protein of viral or host origin.

Adenosine Triphosphate↗
PubMed1982

Further characterization of a protein kinase from foot-and-mouth disease virus.

Acid disruption of foot-and-mouth disease virus released a protein kinase activity that sedimented at less than 7S. This enzyme was separated into three peaks of activity by ion-exchange and hydroxylapatite chromatography. Analysis of the various enzyme fractions by polyacrylamide gel electrophoresis and silver staining revealed that one of the fractions lacked the major virion structural proteins, but still contained two or three other polypeptides. This enzyme phosphorylated mainly one protein (P17) in an in vitro assay.

Animals↗
PubMed1997

Dissecting the roles of VP0 cleavage and RNA packaging in picornavirus capsid stabilization: the structure of empty capsids of foot-and-mouth disease virus.

Empty capsids of foot-and-mouth disease virus (FMDV) type A22 Iraq 24/64, whose structure has been solved by X-ray crystallography, are unusual for picornaviruses since they contain VP2 and VP4, the cleavage products of the protein precursor VP0. Both the N terminus of VP1 and the C terminus of VP4, which pack together close to the icosahedral threefold symmetry axis where three pentamers associate, are more disordered in the empty capsid than they are in the RNA-containing virus. The ordering of these termini in the presence of RNA strengthens interactions within a single protomer and between protomers belonging to different pentamers. The disorder in the FMDV empty capsid forms a subset of that seen in the poliovirus empty capsid, which has VP0 intact. Thus, VP0 cleavage confers stability on the picornavirus capsid over and above that attributable to RNA encapsidation. In both FMDV and poliovirus empty capsids, the internal disordering uncovers a conserved histidine which has been proposed to be involved in the cleavage of VP0. A comparison of the putative active sites in FMDV and poliovirus suggests a structural explanation for the sequence specificity of the cleavage reaction.

Aphthovirus↗
PubMed1998

Antibody response in mice inoculated with DNA expressing foot-and-mouth disease virus capsid proteins.

Candidate foot-and-mouth disease (FMD) DNA vaccines designed to produce viral capsids lacking infectious viral nucleic acid were evaluated. Plasmid DNAs containing a portion of the FMDV genome coding for the capsid precursor protein (P1-2A) and wild-type or mutant viral proteinase 3C (plasmids P12X3C or P12X3C-mut, respectively) were constructed. Cell-free translation reactions programmed with pP12X3C (wild-type 3C) and pP12X3C-mut produced a capsid precursor, but only the reactions programmed with the plasmid encoding the functional proteinase resulted in P1-2A processing and capsid formation. Baby hamster kidney (BHK) cells also produced viral capsid proteins when transfected with these plasmids. Plasmid P12X3C was administered to mice by intramuscular, intradermal, and epithelial (gene gun) inoculations. Anti-FMD virus (FMDV) antibodies were detected by radioimmunoprecipitation (RIP) and plaque reduction neutralization assays only in sera of mice inoculated by using a gene gun. When pP12X3C and pP12X3C-mut were inoculated into mice by using a gene gun, both plasmids elicited an antibody response detectable by RIP but only pP12X3C elicited a neutralizing antibody response. These results suggest that capsid formation in situ is required for effective immunization. Expression and stimulation of an immune response was enhanced by addition of an intron sequence upstream of the coding region, while addition of the FMDV internal ribosome entry site or leader proteinase (L) coding region either had no effect or reduced the immune response.

3C Viral Proteases↗
PubMed2000

The epithelial integrin alphavbeta6 is a receptor for foot-and-mouth disease virus.

Field isolates of foot-and-mouth disease virus (FMDV) have been shown to use the RGD-dependent integrin alphavbeta3 as a cellular receptor on cultured cells. However, several other RGD-dependent integrins may have the potential to act as receptors for FMDV in vivo. Of these, alphavbeta6 is a likely candidate for use as a receptor by FMDV as it is expressed on epithelial cells, which correlates with the tissue tropism of the virus. In this report, we show that human colon carcinoma cells (SW480) that are normally nonpermissive for FMDV become susceptible to infection as a result of transfection with the integrin beta6 subunit and expression of alphavbeta6 at the cell surface. Integrin alphavbeta6 is the major site for virus attachment on the beta6-transfected cells, and binding to alphavbeta6 serves to increase the rate of virus entry into these cells. In addition, we show that virus binding and infection of the beta6-transfected cells is mediated through an RGD-dependent interaction that is specifically inhibited by a monoclonal antibody (10D5) that recognizes alphavbeta6. These studies establish a role for alphavbeta6 as a cellular receptor for FMDV.

Animals↗
PubMed2001

Role of the cytoplasmic domain of the beta-subunit of integrin alpha(v)beta6 in infection by foot-and-mouth disease virus.

Field isolates of foot-and-mouth disease virus (FMDV) are believed to use RGD-dependent integrins as cellular receptors in vivo. Using SW480 cell transfectants, we have recently established that one such integrin, alpha(v)beta6, functions as a receptor for FMDV. This integrin was shown to function as a receptor for virus attachment. However, it was not known if the alpha(v)beta6 receptor itself participated in the events that follow virus binding to the host cell. In the present study, we investigated the effects of various deletion mutations in the beta6 cytoplasmic domain on infection. Our results show that although loss of the beta6 cytoplasmic domain has little effect on virus binding, this domain is essential for infection, indicating a critical role in postattachment events. The importance of endosomal acidification in alpha(v)beta6-mediated infection was confirmed by experiments showing that infection could be blocked by concanamycin A, a specific inhibitor of the vacuolar ATPase.

Acids↗
PubMed1992

The N-terminal amino acid sequence is essential for foot-and-mouth disease virus replicase activity.

1. Foot-and-mouth disease virus replicase was expressed by fusing its cDNA to the OmpA signal peptide coding sequence present in the pIN-III ompA series vectors. 2. Two constructions were developed to express either a full-length or truncated enzyme lacking the 20 amino acids at the N-terminal end. Bacterial extracts expressing the recombinant proteins were submitted to SDS-PAGE and the presence of the replicase was revealed by immunoblotting. The truncated form exhibited a higher mobility and the relative positions of the proteins show that the signal peptide was removed. 3. The biological activity of these two molecules was tested using a poly(A)-dependent oligo(U)-primed poly(U)-polymerase assay. The full-length replicase is active. The aminoterminal truncated enzyme had 0.02% activity of the intact one. 4. This result indicates the importance of the twenty N-terminal amino acids for the activity of FMDV RNA-dependent RNA polymerase.

Amino Acid Sequence↗
PubMed1975

[Studies on the influence of the host system on the result of the neutralization of monodispersed and untreated foot- and mouth disease virus (author's transl)].

Monodispersed foot- and mouth disease virus was obtained by filtration through membranes having a porosity only twice the diameter of the virus. This monodispersed virus was neutralized by immune sera in the same manner as not treated virus. This was shown by the inactivation curve comparing the amount of virus used for the test (calculated as ID50) with the neutralization titre (ND50) or comparing the reduction of infectivity (also calculated as ID50) with the dilution factor of the antiserum. When the virus was assayed by counting the plaque forming units, the monodispersed virus needed more antiserum to be neutralized than a not treated virus suspension. The same mixtures of virus and antiserum were inoculated into different host systems. Using suckling mice there was observed only about 1% of the infectivity measured in primary calf kidney cells. Primary calf kidney cells showed only a tenth of the infectivity seen in BHK-21 cells. The difference between the results in mice and calf kidney cells has been found to be caused by the existence of infectious virus in the mice, which does not cause illness or death in the presence of antibodies. Comparing the same size of cell sheet there is more virus absorbed by BHK-cells in the presence of antibodies than by calf kidney cells. The different results obtained in different hosts for the same virus antibody mixtures are discussed with respect to the detection of small amounts of antibodies and to the limits for the comparison of neutralization titres.

Animals↗
PubMed1984

[Foot-and-mouth disease: the nature and importance of the disease].

The Federal Republic of Germany is at present free from Foot-and-Mouth Disease (FMD). In many countries of the world, however, FMD is still an enzootic disease. Therefore, countries free from FMD have to be constantly on guard against importing the disease. The plurality of the agent as well as ways of transfer of the disease are described. In particular, clinical signs and pathological injuries are described and illustrated by photographs. Methods of preparing specimens from infected animals for laboratory diagnosis are pointed out.

Animals↗
PubMed1996

The 1992 foot-and-mouth disease epizootic in the Kruger National Park.

The monitoring of a foot-and-mouth disease epizootic amongst impala (Aepyceros melampus) in the Kruger National Park is described. Infection rates of different sex and age classes of impala within the outbreak focus were determined. Seroprevalence rates in other clovenhoofed species were also determined. RNA sequencing of a portion of the 1D gene of viruses isolated from SAT-2 viruses obtained from diseased impala showed that they were unrelated to previous SAT-2 isolates made from animals in the Kruger National Park.

Age Distribution↗
PubMed2006

Foot-and-mouth disease - quantification and size distribution of airborne particles emitted by healthy and infected pigs.

There is strong evidence to suggest that foot-and-mouth disease (FMD) can be transmitted by airborne virus up to many kilometres from a virus source. Atmospheric dispersion models are often used to predict where this disease might spread. This study investigated whether FMD virus (FMDV) aerosol has specific characteristics which need to be taken into consideration in these models. The characteristics and infectiousness of particles emitted by 12 pigs have been studied pre- and post-infection with O UKG 2001 FMDV. Aerosol generated by individual pigs was found log normally distributed in the range 0.015-20.0microm with concentrations between 1000 and 10000cm(-3) at the smallest size and <1cm(-3) above 10microm. No differences in either the total number of particles produced or their size distribution were detected between uninfected and infected pigs. However, a correlation between aerosol concentration and animal activity was found with a more active pig producing significantly greater concentrations than those that were less active. Viable virus was found up to a maximum of 6.3 log TCID(50)/24h/animal. The virus was distributed almost equally across the three size ranges; <3, 3-6 and >6microm. No correlation could be established between the production of virus and animal activity. In general the production of airborne virus closely followed the detection of viraemia in the blood and the presence of clinical symptoms. However, in one instance a pig excreted as much airborne virus as the other animals in the study, but with less virus detected in its blood. The results suggest that there is little merit in including a sophisticated virus release pattern based on physical activity periods or FMDV aerosol size spectrum, together with the appropriate dry deposition calculations, in models used to predict airborne spread of FMD. An estimate of the total daily virus production based on the clinical assessment of disease and virus strain is sufficient as input.

Air Microbiology↗