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PubMed1971

Effect of the purification of virus antigens on the production of specific complement-fixing antibodies.

The effect of viral purification procedures on the antibody response of guinea pigs to immunization with reovirus type 2 and echovirus type 19 was investigated. Three grades of antigens were employed: (i) infectious monkey kidney tissue culture fluid (TCF), (ii) virus sedimented in the ultracentrifuge and suspended in phosphate-buffered saline, and (iii) virus purified by centrifugation in CsCl density gradients. The antibody response of the guinea pigs was studied by the hemagglutination inhibition, complement fixation, and serum neutralization tests. Only sera produced from virus purified by CsCl density gradients reacted specifically with homologous antigen in the complement fixation test. Sera from animals receiving tissue culture fluid virus or sedimented virus cross-reacted with heterologous antigens such as tissue culture fluid from uninfected monkey kidney cells. All sera, however, reacted specifically in hemagglutination inhibition and serum neutralization tests. Sera from intranasally infected animals (reovirus type 2), even though reacting specifically in the complement fixation test, had much lower titers than sera from animals inoculated intramuscularly.

Animals↗
PubMed1988

Characterization of potentially foetotropic Palyam serogroup orbiviruses isolated in Zimbabwe.

Twelve Palyam serogroup orbiviruses isolated in Zimbabwe from aborted cattle foetuses, plus one isolated from the visceral organs of a cow and another from vulture faeces, were examined in comparison with known members of the serogroup by complement fixation, indirect immunofluorescence, fluorescent focus reduction neutralization tests and PAGE of the segmented, dsRNA genomes. The viruses were indistinguishable from known members of the serogroup by complement fixation and indirect immunofluorescence, but two novel viruses, for which the names Gweru and Marondera are proposed, and two previously described viruses, Nyabira and Abadina, were identified by neutralization tests. The dsRNA profiles of Abadina serotype isolates differed from that of the Abadina prototype virus, indicating that different electropherotypes may occur within serotypes.

Animals↗
PubMed1970

Direct complement fixation test with avian infectious bronchitis virus in chicken.

The direct complement fixation test was performed to follow the antibody response in chickens infected with avian infectious bronchitis virus. Concentrated allantoic fluid (4 units) was used as an antigen and allowed to react with serially diluted antiserum in the presence of two complete units of guinea-pig complement for 3 hr. at 4 degrees C. and (1/2) hr. at 37 degrees C. before the addition of sensitized cells. Serum was unheated and used either fresh or within one month of storage at -30 degrees C. Individual birds showed a rise and fall of complement-fixing antibody both after primary and secondary inoculations. The complement-fixing antibody was detected as early as the seventh day after primary inoculation. The highest complement fixation titre (1/32 to 1/64) was recorded from 14 to 21 days after inoculation with a subsequent gradual decline.The results of the direct complement fixation tests have been correlated with the serum neutralization test. The neutralizing antibodies usually appeared by the 14th day but were not detected at a significant titre until the 21st day after primary inoculation. Serum neutralizing antibodies were still present at high titres even after 7 weeks of infection but the complement-fixing antibodies had disappeared by that time.

Animals↗
PubMed1977

A mixed outbreak of epidemic keratoconjunctivitis due to adenoviruses types 29 and 8.

An outbreak of epidemic keratoconjunctivitis (EKC) occurred in northern Bohemia in the summer of 1975. One hundred and four patients were treated. Four strains of adenovirus type 29 with low or strong pronounced cross-neutralization against anti-Ad 15 reference serum, and 2 adenovirus type 8 were isolated of 4 patients. Type 8 strains were only obtained from conjunctiva, type 29 also from stools. From one patient, type 8 from conjunctiva and type 29 from stool were isolated simultaneously. Out of 22 patients with demonstrable antibody rise, a monotypic response in virus-neutralization test against type 29 was detected in 13 and a mixed response against types 29 and 8 in nine. An antibody rise was most frequently demonstrated by virus-neutralization test, the frequence for VNT alone being equal to the frequency of antibody rise as detected by VNT, hemagglutination-inhibition test and complement-fixation test in combination.

Adenoviridae↗
PubMed1971

Bluetongue virus: some relationships among North American isolates and further comparisons with EHD virus.

Seven isolates of bluetongue virus with different isolation histories and one isolate of the virus of epizootic hemorrhagic disease of deer were cloned by three consecutive plaquings in L-929 cells. The isolates were categorized on plaque size and margin. Antisera to the bluetongue virus isolates were produced in calves and antiserum to epizootic hemorrhagic disease virus in deer. Plaque reduction neutralization tests were done using the eight isolates and antisera to six of these. The isolates could be partially categorized on plaque type. In the plaque reduction neutralization test, all of the bluetongue viruses cross reacted and although differences were frequently observed, no obvious antigenic classification was possible. Reactions between the bluetongue viruses and epizootic hemorrhagic disease virus were all within the limits of what is presently considered to be non-specific inhibition.

Animals↗
PubMed1982

Diarrheal condition in dogs associated with viruses antigenically related to feline herpesvirus.

Viruses with properties consistent with herpesvirus were isolated from dogs with diarrhea. The viruses were shown to be antigenically related to feline herpesvirus-1 (FHV-1) by virus neutralization tests. It was also observed that a canine herpesvirus (CHV) prototype, D004, and two field isolates from fatal CHV infections in 2-week-old and 6-week-old puppies were neutralized at a low level by antiserum to FHV-1. Reciprocal neutralization tests with CHV antiserum against FHV-1 were negative. These results indicated that viruses related to FHV-1 can infect the dog and that there appears to be uni-directional virus neutralization of CHV by FHV-1 antibody.

Animals↗
PubMed2005

Duplex microsphere-based immunoassay for detection of anti-West Nile virus and anti-St. Louis encephalitis virus immunoglobulin m antibodies.

West Nile (WN) virus was introduced into the United States in 1999, when the first human cases of WN fever and encephalitis appeared in New York City. From there, the virus has spread throughout North America, in some areas cocirculating with the related flavivirus St. Louis encephalitis (SLE) virus. Public health laboratories currently use an immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) as a primary test for human serodiagnosis, followed by a confirmatory plaque-reduction neutralization test (PRNT). The MAC-ELISAs take 2 days to perform; therefore there is a need for a more rapid test. This report describes a duplex microsphere-based immunoassay (MIA) that shortens the test processing time to about 4.5 h. The assay employs two sets of microspheres coupled to a single flavivirus group-reactive antibody, which are used to capture the WN and SLE viral antigens independently. Immunoglobulin G-depleted serum is concurrently assayed for IgM antibodies to each of the viral antigens. The results are standardized and classified by using quadratic discriminant analysis so that a single result, anti-WN IgM-positive, anti-SLE IgM-positive, negative, or nonspecific, can be determined. The duplex MIA results compared favorably to those of the plaque-reduction neutralization test and MAC-ELISA. The assay proved to be reproducible, produced accurate classifications as to the infecting virus, and was specific.

Antibodies, Viral↗
PubMed1975

Recovery of herpes simiae (B virus) from both primary and latent infections in rhesus monkeys.

The suspected ability of herpes simiae (B virus) to persist in a latent form has been confirmed in rhesus monkeys. The virus was recovered from primary oral lesions of 2 young monkeys and again, 6 months after disappearance of symptoms, from cultures of Gasserian ganglia taken from the same individuals. B virus was identified by its effects in vivo and in vitro and in cross neutralization tests with antisera to reference B virus and herpes simplex virus. Tests showed that the same virus was present in oral lesions and in ganglia. The one-way immunological relationship between herpes simplex virus and B virus was clearly shown in results of cross neutralization tests.

Animals↗
PubMed1964

DENGUE-TYPE VIRUSES ISOLATED IN SINGAPORE.

A dengue-like illness with marked haemorrhagic manifestations appeared in Singapore in 1960. Its similarity in many respects to the haemorrhagic fevers of Thailand and the Philippines led to its being described as "Singapore haemorrhagic fever".This paper describes the isolation and identification of dengue-type viruses from patients in Singapore between 1960 and 1962. In addition to the conventional complement-fixation and neutralization tests, a new test, called the "sensitized erythrocyte agglutination test", was employed; this test method is described.Altogether 21 dengue-type viruses were isolated, including dengue types 1, 2 and 4. Chikungunya virus, prominent in the Thailand disease, was not detected.The author suggests that study of the epidemiology of haemorrhagic fevers in South-East Asia would cast further light on the transmission of arboviruses.

Arboviruses↗
PubMed1977

Serotyping avian adenoviruses by a microneutralization procedure.

A microneutralization procedure, using chicken kidney cell monolayers as an indicator system, was developed and applied to the serotyping of isolates characterized as avian adenoviruses. The method was determined to be reproducible, since coefficients of variation were low for 12 replicate titrations of homologous reagents of 9 prototype avian adenoviruses. Prototype reagents were specific according to results of reciprocal end point-neutralization tests and comparison of antigenic relatedness, using results obtained by previous researchers. Forty-two avian adenovirus isolates were classified into 6 serotypes by one-side end point-neutralization tests against antiserums made to 9 prototype avian adenoviruses. An additional 20 isolates were antigenically related to prototype viruses, but they could not be specifically types with the typing criteria. Different serotypes were isolated from birds having similar clinical diagnostic signs and lesions of disease.

Adenoviridae↗
PubMed1979

Poliomyelitis, rubella, and dengue antibody survey in Barbados. A follow-up study.

A follow-up study of poliomyelitis, rubella, and dengue antibodies has been made in light of results obtained in a 1972 health and serological survey in Barbados, W.I. Poliomyelitis antibody neutralization tests performed on sera from 307 children under age 15 using overnight serum/virus mixtures on microtiter plates at low serum dilutions revealed the absence of polio antibody at 1:2 dilution in 13.7% for type 1, 6.5% for type 2, and 14.3% for type 3 virus. A significant correlation of the presence or absence of poliomyelitis antibody to types 2 and 3 was seen with the response to immunization histories. Forty-three of 49 girls (88%) given rubella vaccine (RA 27/3) in 1972 had demonstrable haemagglutination-inhibition antibody 4 years later. Neutralization tests for dengue antibody confirmed the results of the complement-fixation tests and indicated that type 2 was probably the sole infecting strain.

Adolescent↗
PubMed2003

Genetic analysis of the VP1 region of human enterovirus 71 strains isolated in Korea during 2000.

We have isolated Human enterovirus 71 (EV71) from stool and CSF samples taken from patients with acute flaccid paralysis, herpangina, or hand, foot and mouth disease in 2000. Both the cell culture-neutralization test and RT-PCR were used to detect enteroviruses. Rhabdomyosarcoma (RD), HEP2c, and BGM cells were used for the isolation of viruses, and serotypes were determined by the neutralization test using EV71-specific antiserum. For genomic analysis, we amplified a 437-bp fragment of the 5'-noncoding region of the enterovirus genome and a 484-bp fragment of the VP3/VP1 region of EV71 by RT-PCR, with positive results. Products amplified using an EV71-specific primer pair were sequenced and compared with other isolates of EV71. Analysis of the nucleotide sequences of the amplified fragments showed that the EV71 isolates from patients were over 98% homologous and belonged to the genotype C.

Amino Acid Sequence↗
PubMed1979

The latex agglutination test in virus diagnostic: identification of poliomyelitis and coxsackie viruses.

We examined the practical value of the Latex agglutination test (LA test) in diagnostic virology. Viruses isolated from 125 specimens were identified in the LA test. All results were in agreement with those observed by a neutralization test. The LA test appears to be superior to conventional methods because of its easy handling and a rapid and reliable identification.

Cytopathogenic Effect, Viral↗
PubMed1990

A serological comparison of some animal herpesviruses.

Bovine herpesvirus 1 (BHV-1) isolates (Cooper-type strain 4975 and Oxford) were compared in neutralization tests with the bovine herpesvirus 4 (BHV-4) isolate (85/16 TV) and the herpesviruses of red deer (D2839/1) and goats (E/CH). Hyperimmune antiserum was prepared in rabbits against the plaque-selected viruses and endpoint and kinetic neutralization test were made. BHV-4 was clearly different from the other four viruses. The closely-related BHV-1 strains were also related in these tests to the red deer herpesvirus. The Oxford strain seemed rather closer antigenically than the Cooper-type strain to the red deer herpesvirus. Antiserum to the caprine herpesvirus failed to neutralize either BHV-1 strain or red deer virus, but antiserum to the Cooper-type and red deer herpesviruses did neutralize caprine virus to a limited extent.

Animals↗
PubMed1990

Rotavirus serotypes 6 and 10 predominate in cattle.

Calf fecal rotavirus strains were serotyped in enzyme-linked immunosorbent assays, using monoclonal antibodies to the VP7s of serotypes 1, 2, 3, 5, and 6 and to the VP4 of B223 (designated serotype 10). Sixty-six percent of 162 samples were typed as serotype 6, and 7% were serotyped as serotype 10. Most of the untyped strains did not react with a monoclonal antibody directed to a common VP7 epitope, indicating insufficient virus present in the samples. However, seven untyped samples that did react with this antibody were adapted to culture and typed, and six of these also proved to belong to serotype 6 or 10. Two of these viruses belonged to a monotype within serotype 6 that did not react with the serotype 6 monoclonal antibody. The seventh isolate reacted in cross-neutralization tests with serotype 8 viruses. Bovine rotaviruses from the United Kingdom, Federal Republic of Germany, and Japan that had been shown previously to be distinct from serotype 6 were compared in neutralization tests with B223 from the United States. These viruses proved to be a closely reacting group distinct from all other rotavirus serotypes, justifying the establishment of serotype 10 as the second major type of bovine rotavirus.

Animals↗
PubMed2005

West Nile virus infection and serologic response among persons previously vaccinated against yellow fever and Japanese encephalitis viruses.

It is hypothesized that previous heterologous flaviviral exposure may modulate clinical illness among persons infected with West Nile virus (WNV). Little is known about the serological response in such persons. In summer 2003, a WNV outbreak occurred in Colorado, the location of the Centers for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases (DVBID). DVBID employees, most previously vaccinated with yellow fever virus (YFV) or Japanese encephalitis virus (JEV) vaccines, were studied to determine whether previous vaccination affected symptom development among those subsequently infected with WNV during the outbreak, as well as their serological response. Serum samples collected in December 2003 and previously banked samples were tested using the plaque reduction neutralization test (PRNT) against WNV, Saint Louis encephalitis virus, dengue- 4 virus, JEV, and YFV. Specimens shown to have WNV antibody by PRNT were tested by IgM and IgG enzymelinked immunosorbent assays (ELISAs). Ten (9%) of 113 serosurvey participants had WNV neutralizing antibody titers in December 2003. PRNT titers from previous specimens showed that one of the ten had seroconverted to WNV before 2003. Of the remaining nine participants, seven reported illness in the summer of 2003, two of which were unvaccinated and five previously vaccinated. In the December 2003 specimens, five persons previously unvaccinated or vaccinated only against YFV had a fourfold or greater neutralizing titer with WNV than with other flaviviruses, whereas no persons previously vaccinated against JEV or JEV and YFV showed a similar difference in neutralizing titers. Eight of nine persons infected in 2003 had negative or indeterminate WNV MAC-ELISA results in the December 2003 sample; the ninth person was vaccinated against YFV one month previously, and was also YFV positive by MAC-ELISA. We conclude that previous flaviviral vaccination does not markedly affect the development of WNV fever and that the IgM antibody response in patients without neuroinvasive WNV disease is transient.

Adult↗
PubMed1991

Preparation of a neutralizing monoclonal antibody specific to serotype 8 rotavirus strains with a super-short RNA pattern.

Extensive cross-neutralization tests have identified seven serotypes of rotavirus. Recently, it has been reported that several human strains (69M, B37 and B38) with a super-short RNA pattern carry new serotype specificity (serotype 8). By using the strain 69M as an immunizing antigen, we prepared a neutralizing monoclonal antibody (designated 69M-2D). In neutralization tests using 18 human and two animal rotavirus strains with different serotype specificities, the 69M-2D antibody was found to neutralize only serotype 8 strains. Also, in an enzyme-linked immunosorbent assay (ELISA), the antibody reacted exclusively with the serotype 8 strains. Thus, the reactivity pattern of the 69M-2D antibody was serotype 8-specific. This antibody should be useful as another reagent for serotyping rotaviruses by ELISA.

Animals↗