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PubMed1997

Serologic evidence of Jamestown Canyon virus infection in white-tailed deer populations from Connecticut.

We determined the prevalence and distribution of Jamestown Canyon (JC) virus antibody in white-tailed deer (Odocoileus virginianus) populations in Connecticut, USA. Sera were collected from hunter-killed deer during 1993. Antibody to JC virus was detected by enzyme-linked immunosorbent assay (ELISA) in 92 (21%) of 446 deer sera, and was uniformly distributed among geographic sites. Twenty-one ELISA-positive sera were tested and confirmed positive by plaque reduction neutralization testing. This represents the first serologic evidence of JC virus in a reservoir host population from the northeastern United States. No cross-reactivity was seen with California encephalitis, Keystone, or snowshoe hare viruses, but a varying degree of cross-reactivity was obtained with Guaroa, Jerry Slough, La-Crosse, San Angelo, and trivittatus viruses. We conclude from this investigation and previous isolations of JC virus from mosquitoes in the state that JC virus occurs enzootically in Connecticut.

Animals↗
PubMed1992

[Isolation of HAV from sea clam].

Three strains of HAV were isolated directly from clams (Arca Subcrensta Lisckke) collected from sea with cell culture and identified by electron microscopy, immunofluorescent test, ELISA, HAV-cDNA hybridization and neutralization test. The strains were stably passed in 2BS cells with the titer of 4.0-5.0 TCID50/ml. Results indicated that the clams were contaminated by HAV and may cause an outbreak of hepatitis A.

Animals↗
PubMed2003

A passive haemagglutination test for rabies antibodies using rabies glycoprotein coupled erythrocytes.

The presently recommended tests for assaying rabies antibodies like mouse neutralization test (MINT) and rapid fluorescent focus inhibition test (RFFIT) are either time consuming or expensive and are generally performed in reference laboratories. There is a need to develop a specific and rapid method for detection of rabies antibodies that can be used to monitor sero-conversion after pre-or post-exposure vaccination. In this study, we have developed a passive haemagglutination (PHA) using purified rabies virus glycoprotein coupled to sheep erythrocytes using chromium chloride (0.04%) as a coupling agent. Two hundred and fifty five serum samples from people vaccinated with different rabies vaccines, 16 paired serum and CSF samples from autopsy confirmed cases of paralytic rabies, and serum samples from 65 normal healthy controls were tested and evaluated in comparison to standard MNT. Among the vaccinees, 250 samples were positive both by MNT and PHA but 5 samples were negative by PHA and positive by MNT. The titres obtained by PHA were lower compared to MNT, but there was significant correlation between the two (r=0.885). The specificity of the test was 99.7% and sensitivity was 100% as compared to MNT. Thus this PHA test promises to be a rapid and specific test for assaying rabies antibodies and may be useful in screening large number of serum samples for sero conversion after vaccination. It may also assist in rapid laboratory confirmation of paralytic rabies cases, based on detection of antibodies in CSF and serum.

Antigens, Viral↗
PubMed1980

Bovine papular stomatitis, first report of the disease in Mexico.

In a herd of 120 two to eight months old calves kept at a Mexican Government experimental station in Ajuchitlan, Querétaro, weight loss and ptialism were observed. Upon a clinical examination, it was found that 31 (25.8%) of the animals disclosed papules in the oral and perioral regions. Biopsies from the affected tissues were studied with the light and electron microscopes. Serological studies and isolation of the virus were also carried out. A Pox virus was identified (240 x 100 x 150 +/- 7% nm) with the electron microscope. Dermatophilus sp. was occasionally observed. Bovine kidney monolayers, inoculated with affected bovine tissues demonstrated cytopathic effect up to the 4th serial passage. Inoculation with cell cultured infectious material in the oral submucosa (cell lysate) produced typical lesions of BPS on a heifer. Infectious tissues from this experimentally inoculated animal produced cytopathic effect in tissue cultured cells after 24 hours, and this last material was infectious for a second young heifer. Virus-neutralization tests, using an hyperimmune serum, disclosed a neutralization index of 1.5 logarithms. It was concluded that bovine papular stomatitis virus was the etiological agent.

Animals↗
PubMed1981

Epizootic hemorrhagic disease virus in Montana: isolation and serologic survey.

Epizootic hemorrhagic disease virus (EHDV) was isolated in Vero cell culture from the spleen and whole blood of a white-tailed deer (Odocoileus virginianus). A 10% spleen suspension caused acute hemorrhagic disease (HD) when inoculated into an experimental white-tailed deer and resulted in the recovery of EHDV from the blood of the experimental animal at 5 days after inoculation. The virus was identified as EHDV serotype 2 through indirect fluorescent antibody tests, electron microscopy, and reciprocal cross-neutralization tests. Approximately 73% (36/49) of the mule deer, 5% (2/42) of the white-tailed deer, and 79% (249/314) of the cattle samples tested from areas where HD had been reported were EHDV seropositive. Although none of the white-tailed deer was bluetongue virus seropositive, 29% of the mule deer and 3% of the cattle tested from "active" HD areas possessed bluetongue virus precipitating antibody.

Animals↗
PubMed1996

Fowlpox virus structural protein immunogens and characterization of single band polypeptide.

A fowlpox virus isolate obtained from an outbreak of disease in a vaccinated poultry flock was propagated in chicken embryo fibroblast cell culture. Analysis of purified virus polypeptide on 7.5-15% gradient polyacrylamide gel revealed 45 structural polypeptides after Coomassie blue staining. The mol.wt. of polypeptides ranged between 225.53 and 10.50 kDa with total mol.wt. of 2650 kDa. Variable numbers of immunogenic virion polypeptides were detected in immunoblot with fowlpox virus infected chicken sera collected at different time intervals. A total of 29 polypeptides reacted with sera collected at 1st week post-infection and the number gradually declined to 27, 26, 20, 17 and 15 when reacted with 2nd, 3rd, 4th, 5th and 6th week post-infection sera, respectively. Reaction with fowlpox virus hyperimmune sera revealed 35 immunogenic polypeptides. A number of major and minor immunogens were detected. Antisera against seven major single band polypeptides including one double band polypeptide showed very low reactivity both in ELISA and serum neutralization test. Involvement of multigenic components in virus neutralization is indicated.

Animals↗
PubMed1998

A new enzyme immunoassay to detect antibodies to arboviruses in the blood of wild birds.

A new indirect enzyme immunoassay (EIA) was developed to screen wild bird sera for antibodies against western equine encephalomyelitis (WEE) and St. Louis encephalitis (SLE) viruses. The detector antibody was made by immunizing rabbits with serum proteins pooled from single species representatives of four bird orders and was conjugated with horseradish peroxidase to allow visualization with the ABTS substrate in an EIA plate reader set at 405 nm. The detector antibody recognized a wide range of bird species and was more accurate, sensitive, and specific than a hemaglutination inhibition test when compared to a plaque reduction neutralization test (PRNT). EIA positive sera frequently could not be confirmed by PRNT; however, practically all sera positive by PRNT also were positive by EIA. The new EIA has been incorporated into our field research program and has been used to economically screen over 10,000 wild bird sera from 124 species for antibodies against WEE and SLE.

Animals↗
PubMed1990

Presumptive seventh serotype of human rotavirus.

Four group A human rotaviruses having antigenic specificity of subgroup I and 'long' RNA electropherotype were isolated in MA104 cell cultures. Cross-neutralization tests with hyperimmune antisera suggested that they are serologically distinct from the six previously recognized human rotavirus serotypes.

Animals↗
PubMed1973

Effect of heat-labile factors on the neutralization of vaccinia virus by human.

The effect of unheated guinea pig and human prevaccination serum on the neutralization of vaccinia virus was studied. Enhancement of neutralization was found in all sera containing antibody and was more marked (20- to 150-fold) in sera obtained in the first weeks after primary vaccination than in sera from immune adults or cord sera (4- to 25-fold). The enhancing factor was thought to be complement because it was destroyed by heating and ethylenediaminetetraacetic acid treatment. The fresh serum-enhanced neutralization test represents a highly sensitive and specific test which can be applied to measure low levels of vaccinia antibody not detectable by other means.

Adult↗
PubMed1977

Characterization of two new serotypes of San Miguel sea lion virus.

Two new virus isolates, one from a California sea lion (Zalophus californianus californianus) and the other from a northern fur seal (Callorhinus ursinus) were partially characterized. Their physicochemical characteristics were similar to those of vesicular exanthema of swine virus (VESV) and San Miguel sea lion virus (SMSV). The virion morphology was in both instances typically calicivirus. On the basis of this and the serum cross-neutralization testing, these isolates were classed as two new types of SMSV and were designated serotypes SMSV-4 and SMSV-5.

Alaska↗
PubMed1990

Immunohistochemical identification of infectious pancreatic necrosis virus in paraffin-embedded tissues of Atlantic salmon (Salmo salar).

Infectious pancreatic necrosis virus serotype Sp was identified by immunohistochemistry in formaldehyde-fixed and paraffin-embedded tissue of Atlantic salmon (Salmo salar). The immunoreaction was present in degenerating and necrotic cells in exocrine pancreatic cells. Cross reactions were observed with rabbit antisera against serotypes Sp, Ab, and VR-299 in neutralization tests and western blotting. Immunohistochemically, only Sp antiserum produced positive immunostaining to Sp antigens, whereas antisera to serotypes Ab and VR-299 were negative.

Animals↗
PubMed2004

Epizootiology of hemorrhagic disease in mule deer in central Arizona.

We report two male mule deer (Odocoileus hemionus) mortalities that occurred near Prescott, Arizona (USA) in September 2001. Necropsy lesions were compatible with those described for hemorrhagic disease (HD). Bluetongue (BTV) and epizootic hemorrhagic disease (EHDV) viral RNA were identified in tissues from one deer and EHDV viral RNA was identified in the other via reverse transcription-polymerase chain reaction (RT-PCR). Virus isolation attempts were unsuccessful in both cases. To determine geographic range and viral serotypes involved, we collected blood samples from healthy hunter-harvested male mule deer in three game management units near Prescott in October 2001. Forty-one blood samples were collected and antibodies against EHDV and/or BTV were found in 21/41 (51%) samples as determined by agar immunodiffusion. Serum neutralization test results suggest that multiple EHDV and BTV serotypes are present in Arizona.

Animals↗
PubMedDate not supplied

[The humoral immune response to the influenza virus: the characteristics of the enriched virus-neutralizing fraction of hyperimmune mouse serum].

Certain characteristics of immunosorbents prepared on the basis of aminocellulose and oxycellulose were determined. The affinity chromatography of sera from influenza-virus-immunized mice was shown to yield with the former of the immunosorbents a fraction of antibody in which the relative portion of antibodies detectable by neutralization test was higher than that in the original hyperimmune serum. The preparation of pure antibodies obtained with the oxycellulose-based immunosorbent contained antibodies detectable by NT and HI test in a ratio similar to that in the unfractionated hyperimmune serum. It is concluded that aminocellulose and oxycellulose differ in the nature of chemical interaction with influenza virion proteins owing to which differences in the pattern of interaction of immunosorbents prepared on their basis with virus-specific antibodies are observed. The process of influenza virion neutralization by antibodies was also shown to be a multi-hit reaction, the ratio of NT- and HI-detectable antibodies in a preparation affecting the kinetics of the virus-neutralizing effect of the substance. An increase in the preparation of a portion of NT-detectable antibodies reduced the time in which the number of antibody molecules sufficient for virus particle neutralization is adsorbed to it.

Animals↗
PubMed1984

Serologic cross-reaction between bovine herpesviruses 1 and 4 by the enzyme-linked immunosorbent assay.

Reciprocal cross-titrations using constant concentrations of bovine antiserum (1: 100) to either bovine herpesvirus (BHV) 1 or BHV 4 (obtained from controlled infection status) against varying concentrations of both viral antigens in enzyme-linked immunosorbent assay (ELISA) indicated a subtle difference between the antigenic composition of these 2 agents. Although control antiserum consistently yielded higher ELISA titers against homologous viral antigen, a considerable cross-reactivity between the 2 viruses was observed. Based on control sera results, serologic profiling of field bovine serum samples against both BHVs 1 and 4 antigen preparations indicated that the ELISA was unsatisfactory for distinguishing between previous BHV 1 or 4 exposure. The ELISA, however, was more sensitive than the virus neutralization test for detecting antibodies to BHVs 1 and 4 in cattle sera.

Animals↗
PubMedDate not supplied

Evaluation of two intradermal vaccination regimens using purified chick embryo cell vaccine for post-exposure prophylaxis of rabies.

BACKGROUND: Post-exposure prophylaxis for rabies with cell culture vaccines by the conventional intramuscular regimen is very expensive. The World Health Organization has advocated two cost-effective intradermal regimens with cell culture vaccines for use in developing countries. We evaluated these two regimens--the 2-site and the 8-site regimens--in terms of immunogenicity, safety and tolerance in people with category I exposure to rabies. METHOD: Eighty-two subjects who had mild category I exposure to rabies were immunized using a purified chick embryo cell vaccine. The first regimen given to 43 subjects, consisted of intradermal administration of 0.2 ml of vaccine at 2 sites on days 0, 3 and 7 and at one site on days 28 and 90. The second regimen, given to 39 subjects, consisted of intradermal administration of 0.1 ml of vaccine at 8 sites on day 0, at 4 sites on day 7 and at one site on days 28 and 90. The mouse neutralization test was used to estimate titres of rabies neutralizing antibody in these subjects on different days after vaccination. The subjects were followed up for 1 year. RESULTS: Both regimens produced adequate neutralizing antibody titres from day 14 onwards, though the second regimen produced a more rapid antibody response and significantly higher titres (p < 0.001) on all days tested. There were minimal side-effects and both regimens were well tolerated. CONCLUSION: Both the 2-site and 8-site intradermal regimens with purified chick embryo cell vaccine produce adequate levels of neutralizing antibodies but the 8-site regimen appears to be more immunogenic. The feasibility of using these cost-effective regimens in routine practice needs to be further evaluated under the field conditions prevalent in India.

Adult↗
PubMed1984

Indirect and reverse radioimmunoassays and their apparent specificities in the detection of antibodies to enteroviruses in human sera.

Indirect radioimmunoassays (RIAs) of IgM and IgG antibodies to enteroviruses have been developed, using coxsackieviruses B1 and B3, and echoviruses 11 and 30. The titres of IgM and IgG were assayed in paired sera from patients infected with one of these viruses or coxsackieviruses A7, A9, A16, B2, B4, B5 or echoviruses 4, 17, or 25. Both IgM and IgG were found in almost all serum pairs with each of the four viruses used as an antigen, and there were no certain differences between titres obtained with homologous and heterologous antigens. The convalescent phase specimens contained significantly higher titres compared with the acute phase specimens, the difference being most pronounced for IgG. Of the specimens from patients with nonenterovirus infections, a relatively high percentage contained IgM and IgG against enterovirus antigen. However, no increases in titres were seen between acute and convalescent specimens. When specimens from younger patients, aged 2 days to 22 months, without evidence of enterovirus infections, were assayed with enterovirus antigen, the frequency of IgM titres was seen to increase with age. Almost all specimens from newborns were negative, whereas the specimens from 12- to 22-month-old children showed a high frequency of IgM titres. In specimens from patients aged 2 days to 8 months, the ratio between IgM and IgG titres increased with age, probably due to a loss of maternal IgG. The IgG titres in specimens from 8.5- to 22-month-old children were similar to the titres of specimens from the patients with nonenterovirus infections. A reverse IgM assay was also developed, using the same viruses and serum specimens as for the indirect assays. In contrast to the indirect IgM assay, the reverse IgM assay was apparently type specific, provided that the amount of labeled virus was carefully standardized. The reverse IgM RIA detected and identified antibody responses better than the neutralization test. Attempts to develop a reverse IgG assay were promising concerning the specificity, but the sensitivity was low.

Antibodies, Viral↗
PubMed1979

Measurement of antibodies to rabies virus by immunoelectron microscopy.

Immunoelectron microscopy (IEM) was used to measure rabies antibodies in 47 serum samples from vaccinees with results similar to those obtained by mouse neutralization test (MNT). The use of inactivated rabies virus for IEM eliminated the hazard associated with live virus used in the MNT.

Antibodies, Viral↗
PubMed2004

Immunogenicity and safety of a booster vaccination against tick-borne encephalitis more than 3 years following the last immunisation.

This study investigated the immune response and safety in 430 adults, when boosted more than 3 years after primary or booster TBE immunisation as measured by neutralization test (NT) and ELISA. Tested by NT, the post-booster day 21 geometric mean titer (GMT) was 331 and 142 for the 18-49 and > or =50 years old, respectively. The post-/pre-booster geometric mean titer ratio (GMR) was 2.29 for the 18-49 years old and 3.21 for the > or =50 years old. An at least four-fold increase of neutralizing TBE antibodies was observed in only 26 and 38% of subjects aged 18-49 and > or =50 years, respectively. The booster effect in subjects with only the primary vaccination course prior to study entry clearly depended on the time elapsed since last TBE vaccination with an estimated annual decline rate of 15%. In subjects with at least one additional booster vaccination virtually no antibody decline was observed. This study clearly indicates that (1) adults may be effectively and safely boosted with a different TBE vaccine and (2) following four immunisations protective antibodies can be detected far beyond a period of 3 years, thus, strongly supporting the reconsideration of currently recommended booster intervals.

Adolescent↗