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PubMed1984

Antigenic and pathogenic relationships of three bovine rotaviruses and a porcine rotavirus.

The antigenic relationships between three bovine rotaviruses, UK, CP-1 and PP-1, and a porcine rotavirus were investigated; their pathogenicity for piglets was also assessed. After propagation and cloning in cell culture, the four viruses were used to produce convalescent and hyperimmune antisera in gnotobiotic animals. For the UK and PP-1 viruses, reciprocal virus neutralization tests gave ratios of homologous to heterologous titres in the range 57 to greater than 2300. Taking a 20-fold difference in titre to be the criterion of heterogeneity, these two viruses could be regarded as separate serotypes. The third bovine virus, CP-1, was identical to PP-1 in reciprocal neutralization tests but gave a one-way cross-reaction with UK convalescent sera, i.e. it appeared to be intermediate between the two serotypes. UK and CP-1 differed antigenically from the porcine virus as shown by homologous: heterologous neutralization titre ratios of 30 to 12 600. The bovine virus, PP-1, however, had a closer relationship with the porcine virus, the homologous: heterologous ratios ranging from 4 to 110. Oral inoculation of piglets with the bovine viruses revealed differences in their pathogenicity. Isolates UK and CP-1 caused no clinical disease and could not be passaged. However, on the first and second passages in pigs, the bovine virus PP-1 and the porcine virus produced clinical disease, excretion of virus in the faeces and sero-conversion. The results suggest that PP-1 may be a natural hybrid between a bovine and a porcine rotavirus.

Animals↗
PubMed2006

West Nile virus antibodies in avian species of Georgia, USA: 2000-2004.

West Nile virus (WNV) was first isolated in the state of Georgia in the summer of 2001. As amplifying hosts of WNV, avian species play an important role in the distribution and epidemiology of the virus. The objective of this study was to identify avian species that are locally involved as potential amplifying hosts of WNV and can serve as indicators of WNV transmission over the physiographic and land use variation present in the southeastern United States. Avian serum samples (n=14,077) from 83 species of birds captured throughout Georgia during the summers of 2000-2004 were tested by a plaque reduction neutralization test for antibodies to WNV and St. Louis encephalitis virus. Over the 5-year period, WNV-neutralizing antibodies were detected in 869 (6.2%) samples. The WNV seroprevalence increased significantly throughout the study and was species dependent. The highest antibody prevalence rates were detected in rock pigeons (Columba livia), northern cardinals (Cardinalis cardinalis), common ground doves (Columbina passerina), grey catbirds (Deumetella carolinensis), and northern mockingbirds (Mimus polyglottos). Northern cardinals, in addition to having high geometric mean antibody titers and seroprevalence rates, were commonly found in all land use types and physiographic regions. Rock pigeons, common ground doves, grey catbirds, and northern mockingbirds, although also having high seroprevalence rates and high antibody titers against WNV, were more restricted in their distribution and therefore may be of more utility when attempting to assess exposure rates in specific habitat types. Of all species tested, northern cardinals represent the best potential avian indicator species for widespread serologic-based studies of WNV throughout Georgia due to their extensive range, ease of capture, and high antibody rates and titers. Due to the large geographic area covered by this species, their utility as a WNV sentinel species may include most of the eastern United States.

Age Factors↗
PubMed1983

Medicare program; exclusion from Medicare coverage of certain food allergy tests and treatments--HCFA. Proposed notice.

This notice proposes to exclude certain food allergy testing and treatment techniques from Medicare coverage. The procedures that would be excluded from coverage are the cytotoxic leukocyte test, sublingual, intracutaneous and subcutaneous provocative and neutralization testing, and neutralization therapy for food allergies. The Medicare statute and regulations preclude reimbursement for items or services that are not reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member. Available evidence does not show that these tests and therapies for food allergies are safe and effective. Therefore, we are proposing to exclude these techniques from Medicare coverage and provide a uniform Medicare policy concerning these exclusions.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1997

Hyper-antigenic variation occurs with human rhinovirus type 17.

Of 90 human rhinovirus (RV) serotypes tested, 50 can be placed into 16 groups according to antigenic relationships. It has been suggested that antigenic variants might arise in nature by immunologic pressure. To investigate this possibility, attempts were made to select variants by cloning 16 different plaque-purified RV serotypes in the presence of homologous, polyclonal antisera. Isolates were examined for evidence of variation in serum cross-neutralization tests using parental antisera and, in some cases, antisera prepared for the isolates. Only RV type 17 (RV-17) yielded major antigenic variants after cloning. With some variants, as much as a 500-fold difference in neutralizing titer was obtained with the parental antiserum. By using antisera for two of the variants, it was determined that they are prime strains of the parental RV-17. Continuing attempts at immunoselection by using antisera for one of these prime strains yielded additional antigenic variants. By using antisera prepared for three of these new variants, it was determined that one of them is a prime strain of the virus from which it was derived. Cross-neutralization tests with the two remaining isolates indicate that, according to conventional practice, they no longer would be classified as RV-17.

Animals↗
PubMed2002

Antibody persistence in five-year-old children who received a pentavalent combination vaccine in infancy.

BACKGROUND: Antibody persistence was studied in 5.5-year-old Swedish children who in infancy completed a vaccine trial of a combined diphtheria toxoid, tetanus toxoid, acellular pertussis, inactivated polio and Haemophilus influenzae type b conjugate vaccine. Three priming doses at ages 2-4-6 months induced higher geometric mean concentrations of antibodies for all antigens than did two doses at 3-5 months, but there were no differences in proportions with protective antibody concentrations. After the booster dose administered at 13 or 12 months of age, respectively, there were no differences in concentrations or proportions between the groups. METHODS: In the present follow-up serum samples from 180 of the 228 vaccinees, 88 from the 4-dose and 92 from the 3-dose group, were 4.5 years later again tested for antibodies. RESULTS: The two groups did not differ significantly in antibody concentrations or proportions with antibodies above protective or other defined levels, with the exception of poliovirus type 3 (P < or = 0.01). In all 89% had > or = 0.01 IU/ml antibodies against diphtheria by enzyme-linked immunosorbent assay and 76% by the Vero cell neutralization test, 93% had > or = 0.01 IU/ml antibodies against tetanus, 96 to 99% had detectable antibodies against the polioviruses and 97% had > or = 0.15 microg/ml H. influenzae type b antibodies. As for pertussis only 44% had detectable antibodies against pertussis toxoid by enzyme-linked immunosorbent assay but 99% by Chinese hamster ovary cell neutralization test, and 94% had detectable antibodies against filamentous hemagglutinin. CONCLUSION: We found the persistence of antibodies satisfactory, with no clinically relevant differences in antibody concentrations demonstrated between children vaccinated according to a three dose or a four dose schedule in infancy.

Antibodies, Bacterial↗
PubMed1993

Laboratory investigation of PRRS virus infection in three swine herds.

Late in 1991, an enveloped RNA virus (now called porcine reproductive and respiratory syndrome [PRRS] virus) was identified as the etiologic agent for mystery swine disease. In 1992, laboratory procedures for the diagnosis of this disease evolved rapidly, and veterinary diagnosticians started applying these tests to field cases. This report is written from the perspective of veterinary laboratory diagnosticians and utilizes 3 case studies to define the advantages and disadvantages of the various available diagnostic laboratory PRRS test procedures in different clinical situations. The diagnostic procedures currently used in our laboratory for investigating PRRS are pathologic examination, serologic testing, fluorescent antibody (FA) testing, and virus isolation. Interstitial pneumonia, characterized by mononuclear cell infiltration of alveolar walls with normal airway epithelium, is a hallmark lesion for the disease, especially in neonatal pigs with respiratory distress. Interstitial pneumonia is not a specific lesion and must be coupled with other tests to verify PRRS virus infection. Demonstration of seroconversion is helpful, especially in sows that have experienced reproductive failure. The indirect FA test detects antibody sooner than the serum neutralization test and will likely become the serologic test of choice. The direct FA test on fresh tissue utilizes monoclonal antibody and is useful for investigating PRRS virus-associated pneumonia. Virus isolation utilizing swine alveolar macrophages has also been a useful diagnostic procedure. All of the above tests have been universally unrewarding when applied to aborted, mummified, or stillborn piglets.

Animals↗
PubMed1974

Antigenic relationships among Newcastle disease virus mutants obtained from laboratory strains and from recent California isolates.

The antigenic relationship between pairs of plaque mutants of Newcastle disease virus (NDV) derived from laboratory strains and from isolates from the 1971-72 California epizootic were examined by kinetic neutralization test. Comparing four sets of mutants from laboratory strains by both kinetic neutralization and hemagglutination inhibition tests, a similarity was found in the antigenic relationship expressed as an r value with both tests. However, kinetic neutralization was the more precise as well as sensitive assay. Antigenic diversity was greatest between pairs of mutants from different strains, but distinctions could also be made between mutants from the same strains such as Herts-L and Herts-S with an r value of 36%. Examination of mutants from the California epizootic isolated from separate locations and at different times showed antigenic divergence which was greatest between two red-plaque mutants with an r value of 39%. Antigenic distinctions were found between a red- and clear-plaque mutant obtained from isolates taken from brain and tracheal swabs of one infected chicken. In addition to antigenic divergence found between pairs of some mutants, two of the clear-plaque mutants reacted more avidly with antibody than did the corresponding red-plaque partner. Thus, both differences in antigenicity and avidity can be found among these NDV mutants. The antigenic variation found among these mutants is similar to that found within a serotype. This would imply that at the present NDV is a single serological type.

Animals↗
PubMed1977

Anti-complement immunofluorescence test for antibodies to human cytomegalovirus.

An anti-complement immunofluorescence (ACIF) test that detects human cytomegalovirus (CMV) antigen in the nuclei of infected cells was used for assay of CMV antibodies in human sera. Various factors influencing the sensitivity and specificity of the ACIF test system were investigated, and results were applied to the development of a procedure which could be completed in a relatively short length of time and gave reproducible results. Results obtained in the ACIF test were compared with those obtained in complement fixation, indirect hemagglutination, and neutralization tests, and the ACIF test was shown to be suitable for detection of significant antibody titer rises and stationary levels of CMV antibody. Heterotypic antibody responses were not seen with sera from other human herpesvirus infections. The nonspecific cytoplasmic staining that occurs in indirect immunofluorescence tests for CMV did not occur in the ACIF system, and sera that were anti-complementary in complement fixation tests could be examined satisfactorily by ACIF. Thus, the test is a valuable supplemental or back-up procedure for the serodiagnosis of CMV infection.

Antibodies, Viral↗
PubMed1978

Genetic analysis of a cytomegalovirus-like agent isolated from human brain.

An unusual cytomegalovirus (CMV, strain Colburn) isolated from brain biopsy of a boy with clinical encephalopathy was studied for genetic relatedness to human and simian CMV. Cross-examination of the purified viral DNA by DNA-DNA reassociation kinetics analyses showed more than 90% homology between Colburn virus and simian CMV (strain GR2757) and a lack of detectable homology between Colburn virus and human CMV (strains AD-169 and TW-87). Restriction endonuclease analysis of Colburn DNA showed some similarity of the DNA fragment pattern with that of simian CMV DNA, although the DNA fragment patterns were not identical, and showed no similarity to that of human CMV DNA. The molecular size and density of viral DNA were close to those of simian CMV DNA. The antigenic study, as performed by complement fixation and neutralization tests, showed strong cross-reactivity of Colburn virus to simian GR2757 virus. One-way cross-reaction of Colburn virus to several human CMV isolates (AD-169, Davis, and Town) was detected by complement fixation; this one-way cross-reaction was not obvious in a plaque neutralization test. It was concluded that Colburn is a simian CMV-related virus.

Animals↗
PubMedDate not supplied

[Sindbis viruses of various geographic origin and differentiation of them from Western equine encephalomyelitis viruses using the polymerase chain reaction].

Comparison of Sindbis virus strains isolated in different regions of the world (in Africa, Australia, and Europe, including Russia and its nearest neighbors) in the polymerase chain reaction (PCR) by the primary gene structure of proteins NSP1 and E1 and in the neutralization test showed the greatest similarity between geographically close strains isolated in Northern Europe (KFL, Karelia, 1381 and 1388, Estonia). Sindbis strains AR339 and Babanki isolated in Africa were similar to each other and to strains from Northern Europe by the examined gene sites but different from the Northern variants in the neutralization test. Geographically remote strains F-720 (Armenia and Southern Europe) and Whataroa (New Zealand) were close to Sindbis virus from Africa and Northern Europe by only one of the genes examined (F-720 by NSP1 and Whataroa by E1). PCR was carried out using oligonucleotide primers containing nucleotide sequences identical to genes NSP1 and E1 sites of Sindbis strains HRSP, Okelbo, and KFL, but different from gene sites of other known representatives of alphaviruses by at least 5 positions. PCR analysis showed that the appurtenance of the geographic variants to Sindbis group can be ascertained only after investigating the homology of at least two genes coding for the replicative and structural proteins. Such a procedure of PCR permits the detection of Sindbis viruses of different geographic origin with changes in their primary structure and allows the differentiation between Sindbis viruses and Western equine encephalomyelitis viruses within the serological complex.

Encephalitis Virus, Western Equine↗
PubMed1954

Immunochemical studies of antitoxin produced in normal and allergic individuals hyperimmunized with diphtheria toxoid. IV. Differences between human precipitating and non-precipitating skin-sensitizing diphtheria antitoxin as shown by electrophoresis.

Electrophoresis on a starch-supporting medium was used to fractionate sera containing human diphtheria antitoxin of the following varieties (a) precipitating antitoxin, (b) non-precipitating skin-sensitizing antitoxin, and (c) mixtures containing precipitating and skin-sensitizing antitoxins. Aliquots of the protein fractions thus separated were tested for activity using the rabbit toxin neutralization test, precipitin techniques, and passive transfer tests in human skin. Non-precipitating, skin-sensitizing diphtheria antitoxin migrated largely as a fast moving gamma (gamma(1)) globulin. Passive transfer studies of isolated antitoxic fractions showed that they were as potent as whole serum in the ability to cause immediate wheal reactions. These fractions were not precipitable using appropriate quantities of purified toxoid. Precipitating diphtheria antitoxin migrated largely as a slow moving gamma (gamma(2)) globulin. Isolated antitoxic fractions of appropriate strength obtained from representative sera were precipitable by toxin and were unable to cause immediate wheal reactions upon toxoid challenge in human recipients. Mixtures of skin-sensitizing and precipitating antitoxins were separable by the technique of starch electrophoresis. The individual components removed from mixtures by this method retained the properties by which they could be characterized in whole serum.

Antibodies↗
PubMed1990

Antigenic relationships among human rotaviruses as determined by outer capsid protein VP4.

cDNA clones representing the VP4 gene of symptomatic human rotavirus strain KU (VP7 serotype 1) or DS-1 (VP7 serotype 2) or asymptomatic human rotavirus strain 1076 (VP7 serotype 2) were constructed and inserted into a baculovirus expression vector under the control of the polyhedrin promoter. The resulting recombinants expressed the appropriate authentic VP4 rotavirus outer capsid protein. Guinea pigs immunized with these VP4 proteins developed antibodies that neutralized infectivity of the rotavirus from which the immunizing VP4 was derived. These antisera were then used in neutralization tests to define the extent and distribution of VP4 antigenic polymorphism among human rotaviruses. Three distinct serotypes and one subtype of the VP4 outer capsid protein were identified among 17 human rotavirus strains that had previously been assigned to five distinct VP7 serotypes. For the most part, VP4 serotype segregated independently of VP7 serotype. Ten strains of human rotavirus that were associated with symptomatic infection and that exhibited VP7 serotype 1, 3, 4, or 9 specificity, each possessed a VP4 of the same serotype and subtype, designated VP4 serotype 1A. Both symptomatic human rotavirus strains with VP7 serotype 2 specificity were related by neutralization to the VP4 serotype 1A strains and were classified as a subtype of VP4 serotype 1--i.e., serotype 1B--since viruses of serotype 1A appeared to be prime strains. Four human rotavirus strains that were recovered from healthy infants in newborn nurseries in which virus transmission persisted over a long interval, belonged to VP7 serotype 1, 2, 3, or 4, but each strain possessed the same VP4 antigenic specificity that was designated VP4 serotype 2. Finally, a single strain of symptomatic human rotavirus of VP7 serotype 1 specificity possessed a unique VP4 that was provisionally classified as VP4 serotype 3 but this remains to be confirmed because neutralization tests were performed in only one direction. Among the 10 rotavirus strains whose VP4 gene was previously sequenced, there was complete concordance between assignment of VP4 serotype by neutralization and classification according to VP4 amino acid homology. Thus, rotaviruses that exhibited a VP4 amino acid homology of 89% or greater belonged to the same VP4 serotype and subtype as determined by neutralization. Finally, evidence was obtained that the serotype-specific domain is located on the VP8 subunit of VP4.

Animals↗
PubMed1983

Monoclonal antibodies reactive with different sites of N and H antigenic particles of poliovirus.

We established three hybridomas (designated 2A12, 4C4 and 6H8) secreting monoclonal antibodies which react with N and H(heated) antigenic particles of poliovirus type 1 (Mahoney strain). One of these monoclonal antibodies, 4C4, had virus-neutralizing activity, while the other two were non-neutralizing. A solid-phase radioimmunoassay and a neutralization test indicated that the specificity of the neutralizing monoclonal antibody 4C4 was the same as that of the monospecific antibody HN31, previously prepared by us by absorbing poliovirus antiserum with an equine serum inhibitor-resistant mutant (M-HN31) of poliovirus. Furthermore, by means of immune electron microscopy, it was revealed that the combining site of the 4C4 neutralizing monoclonal antibody is on or around vertices of the N and H antigenic particles, while the other two monoclonal antibodies are directed to the entire surface of the antigens.

Antibodies, Monoclonal↗
PubMed1990

Identification of monoclonal antibodies that distinguish between 17D-204 and other strains of yellow fever virus.

Eight monoclonal antibodies (MAbs) prepared against the flaviviruses Saint Louis encephalitis, dengue 2 and dengue 3 viruses all recognized epitopes on the envelope protein of the prototype flavivirus, yellow fever (YF) virus. Three of these MAbs with flavivirus group-common specificity and two MAbs with a flavivirus-subgroup specificity were found to distinguish wild-type YF viruses from YF 17D-204 vaccine virus, but not from the closely related 17DD vaccine virus, nor from the French neurotropic vaccine virus. This pattern of reactivity was seen only with viruses grown in Aedes albopictus C6/36 cells and not with viruses grown in vertebrate cells (SW13 and Vero cells), where all five MAbs recognized epitopes on both wild-type and 17D-204 viruses. Examination of adult A. aegypti mosquitoes infected with the same YF viruses as above gave a different pattern of results to those in C6/36 cells. Thus, epitope expression differs between mammalian and arthropod cells and between arthropod cells in vitro and in vivo. Neutralization tests showed that all five MAbs would neutralize wild-type Asibi virus grown in SW13 cells, but not Asibi virus grown in C6/36 cells, nor 17D-204 vaccine virus grown in either cell type. Therefore, it is concluded that when YF virus is grown in mosquito cells, wild-type virus is antigenically and biologically distinct from the 17D-204 vaccine virus.

Adenocarcinoma↗
PubMed1962

Interrelationships among ECHO virus types 1,8, and 12.

Berg, Gerald (Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio), Norman A. Clarke, and Paul W. Kabler. Interrelationships among ECHO virus types 1, 8, and 12. J. Bacteriol. 83:556-560. 1962.-Antigenic relationships among ECHO 1, 8, and 12 viruses were investigated. Three strains of ECHO 1 virus, one of which had been purified, could not be differentiated by neutralization tests. Antiserums produced with these three strains neutralized ECHO 12 virus. The neutralizing material, absent from preimmunization serums, was not absorbed by rhesus kidney cells, was heat-stable, and, therefore, may be viral antibody. Reciprocal neutralization was achieved with all three types. Disagreement of these data with those published by others is discussed.

Enterovirus B, Human↗
PubMed1984

Quantitation of enterovirus 70 antibody by microneutralization test and comparison with standard neutralization, hemagglutination inhibition, and complement fixation tests with different virus strains.

We describe here a microneutralization procedure for conveniently testing large numbers of specimens for antibodies to enterovirus 70. The test utilized human rhabdomyosarcoma cells and was read by staining with crystal violet after 4 days of incubation. The test compares well with other serological assays, being more sensitive than the standard tube neutralization test and the complement fixation test, but less sensitive than the hemagglutination inhibition test. However, the hemagglutination inhibition test required concentrated, partially purified virus as antigen, as did the complement fixation test, and was difficult to read, so that its greater sensitivity may not be of practical significance. By all four test procedures, a recent isolate of enterovirus 70 was a more sensitive antigen than the prototype strain, as shown by greater geometric mean titers in sera of patients from various epidemics.

Antibodies, Viral↗
PubMed2000

[Studies on clinical trials and immune effect of a new purified rabies vaccine prepared from Vero cells].

OBJECTIVE: To observe the safety and neutralizing antibody response of a new purified rabies vaccine prepared from Vero cells. METHODS: The vaccine used was manufactured in Hainan Institute of Biologicals and licensed by the Ministry of Health for clinical trials. The vaccine was administrated in 30 and 318 volunteers during phase I and II clinical trials with preexposure (day 0, 7, and 28) or post exposure (day 0,3,7,14 and 28) vaccination schedules. The "Verorab (PVRV)", a rabies vaccine made in France was used as control. RESULTS: The results showed that the new purified vaccine did not cause any severe and moderate side reactions, the slight side reaction rate was 12% including those complained by vaccines themselves. The immunological effect was determined by detecting neutralizing antibody with mouse neutralization test (NIH). The positive seroconversion rates of neutralizing antibody were 100% (n= 27, GMT 2.89 IU/ml) and 100% (n= 30, GMT 5.29 IU/ml) respectively by pre- exposure and post exposure schedules. No significant difference was found when compared with France "Verorab" vaccine by preexposure schedule (n= 24, GMT 2.13 IU/ml). CONCLUSIONS: The clinical trials indicated that the purified rabies vaccine prepared from Vero cells only showed slight side reaction and had good neutralizing antibody response. Therefore this new vaccine is safe and protective for the prevention of rabies in human.

Animals↗
PubMed1977

Serodiagnosis of influenza by indirect haemagglutination test.

Results of studies on serodiagnosis of influenza A and B by the indirect haemagglutination test (IHA) with lyophilized erythrocyte diagnostic preparations, highly stable upon storage, are presented. The diagnostic value of the IHA test was in good agreement with, that of virus neutralization tests.

Adult↗