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PubMed1978

Antigenic relationship between influenza C viruses.

The object of this study was to determine whether antigenic groupings exist among influenza C viruses. Altogether seven influenza type C strains were examined by reciprocal haemagglutination-inhibition and serum neutralization tests with sera produced in ferrets. Some biological properties were also compared and differences were found in their ability to agglutinate erythrocytes from various species, in their ability to adsorb onto rat and fowl erythrocytes, and in their rates of elution from the cells. The results obtained using these techniques confirmed that antigenic variation exists among influenza C viruses although it is not as clear cut as among influenza A viruses. This was supported by the results of a serological survey of antibody in different age groups.

Animals↗
PubMed1990

Stability of metacyclic variable antigen types (M-VATs) during the early stages of infection with Trypanosoma congolense.

Expression of nine metacyclic variable antigen types (M-VATs) of Trypanosoma congolense in chancres from infected rabbits was determined using monoclonal antibodies raised against metacyclic forms of trypanosomes. Trypanosomes present in chancres 7-9 days post infection expressed M-VATs present in metacyclic populations of the parasites. The majority of M-VATs expressed showed little proportional change from those observed on metacyclic trypanosomes during this period although expression of one M-VAT increased, and another decreased. Although trypanosomes in chancres continued to express M-VATs, other VATs, not present in the M-VAT repertoire were also expressed and neutralization tests showed that new VATs appeared by 7 days after infection. In infected sheep neutralizing antibodies against M-VATs were detected by day 14 in lymph from efferent lymphatics draining lymph nodes in the region of chancres. Neutralizing antibodies directed against metacyclics were also present in the serum by day 14 and were still detectable for up to 35 days post infection. Hence, it is likely that in the vertebrate host the trypanosomes multiplying in the skin at the site of tsetse bit express all M-VATs characteristic of that particular serodeme, enabling the host to develop immunity to all antigen types present in the M-VAT repertoire.

Animals↗
PubMed1998

Establishment of a serum-free culture cell line, CPK-NS, which is useful for assays of classical swine fever virus.

A stable porcine kidney cell line, CPK-NS, was established and maintained in serum-free culture. A cytopathic effect (CPE) was observed clearly in CPK-NS cells infected with some classical swine fever virus (CSFV) strains which did not show the exaltation of Newcastle disease virus (END) phenomenon. Chromosome condensation and DNA fragmentation, a marker for apoptosis, were detected in cells infected with END phenomenon-negative CSFV strains. By using the CPE induced by infection with an END phenomenon-negative CSFV strain in CPK-NS cells, assays of CSFV were established. The virus titer determined in CPK-NS cells shows a high correlation with the usual peroxidase-linked assay, dome disappearance method and END method. Furthermore, the antibody titer by neutralizing test with CPK-NS cells also correlated with that measured by the usual neutralizing peroxidase-linked assay and dome disappearance method. These stable CPK-NS cells have the great advantage that a clear CPE was caused by infection with END phenomenon-negative CSFV strains and bovine serum is not necessary for cell culture and virus assays.

Animals↗
PubMed1998

Serological evidence of morbillivirus infection in small cetaceans from the Southeast Pacific.

The presence of morbillivirus-specific serum antibodies was examined by an indirect enzyme linked immunosorbent assay (iELISA) and virus neutralization tests in serum samples from 30 dusky dolphins (Lagenorhynchus obscurus), 8 long-snouted common dolphins (Delphinus capensis), 2 inshore and 6 offshore bottlenose dolphins (Tursiops truncatus) and 20 Burmeister's porpoises (Phocoena spinipinnis) taken in fisheries off central Peru in 1993-1995. The sera from six dusky dolphins, one common dolphin and three offshore bottlenose dolphins were positive on a coat of dolphin morbillivirus (DMV) antigen in the iELISA. Several of these sera were also positive when tested against peste des petits ruminants and rinderpest virus antigen. Porpoise morbillivirus and/or DMV neutralizing antibodies were detected in the sera of two bottlenose and three dusky dolphins that reacted positively with DMV antigen in iELISA and also in the sera of one common, one dusky and one bottlenose dolphin that were negative in the iELISA. These results strongly suggest that viruses closely related, or identical, to the cetacean morbillivirus present in the North Atlantic and the Mediterranean Sea infect several species of Delphinidae of the Southeastern Pacific. No convincing morbillivirus-specific antibody positive reactions were detected in the sera from either the Burmeister's porpoises or the inshore bottlenose dolphins.

Animals↗
PubMed1979

Antigenic analysis of human cytomegalovirus isolates from Japanese women and infants.

The antigenic differences among human cytomegalovirus (CMV), two laboratory strains (Davis, AD 169), isolates from pregnant women's cervical secretions, mother's milk, infants' throat swabs and urine were analyzed by means of the plaque reduction assay using human sera which were assumed to contain monotypic antibodies by primary infection and boosted antibodies by reinfection or reactivation of the latent virus. In the cross-neutralization tests, there were no remarkable differences among the CMV strains examined. Moreover, in the neutralization kinetics, normalized kappa values among the strains constantly exceeded 80. Therefore, it is suggested that the human CMV strains examined in the study were serologically identical or very closely related.

Antigens, Viral↗
PubMed1990

A nosocomial outbreak of epidemic keratoconjunctivitis due to adenovirus type 37.

An outbreak of epidemic keratoconjunctivitis occurred at the department of ophthalmology of a hospital in Yokohama, involving 14 inpatients, 12 outpatients, and 2 doctors. Adenovirus type 37 (Ad-37) was isolated from the conjunctival swab in 12 of 18 cases. In neutralization tests, the isolates showed some cross-reaction with adenovirus type 19 (Ad-19). The Ad-37 isolates were indistinguishable from each other and from the prototype Ad-37, but distinct from the prototype Ad-19 in the restriction endonuclease analysis of viral DNA.

Adenovirus Infections, Human↗
PubMed1991

Enzyme immunoassay for detection of antibodies against eastern equine encephalomyelitis virus in sentinel chickens.

We developed an enzyme immunoassay (EIA) for the detection of immunoglobulin M (IgM) and IgG subclass antibodies directed against eastern equine encephalomyelitis (EEE) virus in chickens. The assays were compared with the serum plaque reduction neutralization test (PRNT) and the hemagglutination inhibition (HI) test for ability to detect antibodies against EEE virus in laboratory-infected birds. No cross-reactivity was detected in serum from chickens inoculated with St. Louis encephalitis or Highlands J virus. The interval after infection when EEE virus-specific antibodies were first detected by IgM and IgG EIAs was found to be similar to that determined by the PRNT and HI tests: 2 to 4 days. The IgG EIA, PRNT, and HI test detected antibodies to EEE virus for at least 27 to 30 days after inoculation. In contrast, serum from five of seven chickens did not contain detectable IgM 30 days after infection. Similarly, in all three naturally infected sentinel chickens from Maryland, IgM class antibody was undetectable 1 to 5 weeks after IgM was initially detected. EIAs provide simple and rapid alternatives to traditional tests for monitoring EEE virus infections in sentinel chicken flocks. Moreover, the IgM EIA provides a means to separate recently infected chickens from those infected greater than or equal to 1 month earlier.

Animals↗
PubMed1995

A retrospective serological survey of the encephalomyocarditis virus among pigs in Chiba prefecture, Japan.

One thousand two hundred and forty pigs' sera collected from 1975 to 1992 on 240 farms in Chiba prefecture were subjected to a neutralization test for the encephalomyocarditis (EMC) virus. Seven (23.3%) of 30 pigs in 1975 had neutralizing antibodies against the EMC virus. The antibody positive rates each year ranged from 16.7% (1976) to 56.3% (1981). The differences of antibody positive rates between districts were not great after 1985. These serological results suggested that the EMC virus infection had already been introduced by 1975 and that it is prevalent among pigs in Chiba prefecture.

Animals↗
PubMed2001

[Differential diagnosis of classical swine fever and border disease: seroepidemiological investigation of a pestivirus infection on a mixed sheep and swine farm].

During recent years neutralizing antibodies against Border Disease Virus (BDV) were found repeatedly in German pig herds. Consequently there was a demand for a differential diagnostic system. A permanent sheep cell line and BDV reference strain Moredun were chosen and were applied in a could be used case study. A pestivirus could be isolated from piglets on a mixed farm and was characterised as 'non-Classical Swine Fever' (CSF) by using monoclonal antibodies. Due to a CSF suspicion the pig herd was destroyed immediately. Serum samples of sheep from the same farm were used for further characterisation of the new virus isolate. A neutralization test of the sheep sera was performed against different pestiviruses and the new isolate. Neutralizing antibody titres against the new virus pig isolate were significantly higher than against all other pestiviruses. BDV strain Moredun recognised the antibodies clearly, whereas CSF viral strain Alfort 187 and several isolates of bovine viral diarrhoea virus (BVDV) strains scored the lowest cross reaction.

Animals↗
PubMed1988

Dependence on the birth season of the antibody level against West Nile virus in the Pakistani population.

Variation of antibody level against West Nile (WN) virus depending on the season of birth was followed among 151 paired serum samples of healthy Pakistani persons in Karachi, collected twice in July and October, 1985. The persons born during the months between February and June had lower positive antibody rate and lower responsiveness in haemagglutination inhibition and neutralizing tests against WN virus than those born during the other months. This phenomenon implies that the ability to produce antibodies against WN virus among Pakistani persons may depend on their birth season.

Adolescent↗
PubMed1980

A plaque assay for malignant catarrhal fever virus and virus neutralizing activity.

A cell-free strain of malignant catarrhal fever virus which produced a readily recognizable cytopathic effect was obtained by serial passage of the virus in a rabbit kidney cell line. Plaque assay of the virus was more rapid and gave higher titres 11 days postinoculation than tube titration, but the latter advantage decreased with a longer incubation period. Plaques were clear with sharp edges and measured 0.5 to 2 mm in diameter after 15 days. A plaque neutralization test was developed and successfully employed for the titration of malignant catarrhal fever virus neutralizing activity in the sera and nasal secretions of blue wildebeest.

Animals↗
PubMedDate not supplied

Rapid and quantitative assay system for measuring anti-infectious bursal disease virus antibody using monoclonal antibody bound to polystyrene latex microspheres.

A monoclonal antibody (MAb) to infectious bursal disease virus (IBDV) that has virus-neutralizing activity was bound to polystyrene latex microspheres The microspheres agglutinated with extracts of bursae from chickens infected with IBDV. Agglutination was inhibited in a competitive manner by adding serum obtained from IBDV-infected chickens. The level of agglutination-inhibition depended on the serum antibody titer against IBDV. The reaction was visually accomplished within 5 minutes. The titer of this rapid assay showed a close relationship with that of the virus-neutralization test.

Animals↗
PubMed1984

A comparison of the antibody responses of badgers (Meles meles) and rabbits (Oryctolagus cuniculus) to some common antigens.

The primary and secondary antibody responses of rabbits and badgers were compared after intravenous inoculation of inactivated influenza A virus, sheep erythrocytes (SRBCs), bovine serum albumin (BSA) or bacteriophage psi X174. BSA was also given as a primary injection by the intramuscular route in solution or in Freund's incomplete or complete adjuvant, followed by an intravenous secondary inoculation without adjuvant. Antibody responses were monitored by: haemagglutination inhibition and neutralization tests for influenza virus; direct and antiglobulin haemagglutination tests for SRBCs; indirect haemagglutination test and the Farr method for antigen-binding capacity (ABC) for BSA; neutralization of psi X174. Rabbits gave good responses to all antigens, but the response of badgers was generally poor. After intravenous administration, badgers gave a good response only to psi X174, but even then they produced less antibody than rabbits receiving 100 times less antigen; the immune elimination of phage was more rapid and antibody appeared about 48 h earlier in rabbits than in badgers. Intramuscular administration of BSA and the use of adjuvants improved the badgers' response, with greatest improvement in ABC. These results indicate that badgers display relatively poor immune responses to a variety of antigens.

Animals↗
PubMed1992

[Prevalence of anti-HCV (C100-3) antibodies in 20.373 blood donors].

The anti-HCV antibody (C100-3) is present in the serum of 70-90% of patients that are carriers of posttransfusion non-A non-B hepatitis. This marker appears to be associated with a viral replication and infectiousness state. Since 1st August 1990 the Swiss Red Cross Transfusion Service has operated a systematic search for anti-HCV antibodies for every blood donation. The aim of the study was to establish the prevalence of anti-HCV antibodies in a donor population, look for the risk factors in the anti-HCV positive group, look for biological symptoms and signs of chronic hepatitis, and compare the data with that from an anti-HCV negative control group. From August to March 1991, 20,373 donors were tested by EIA (Ortho). The presence of anti-HCV antibody was confirmed by a neutralization test (Abbott). The donors in which both tests were positive formed the group studied (55 subjects). Their data was compared with that of a control group of anti-HCV negative donors. The prevalence of anti-HCV antibody in the group of 20,373 donors was 0.29%. Possible parenteral exposure to hepatitis C virus was found in 47% of anti-HCV positive subjects (30% blood transfusion, 9% i.v. drug addiction, 8% tattooing). 42% of the anti-HCV positive donors had no risk factor presently known for hepatitis C. 27% of anti-HCV positive donors had elevated transaminase levels. Until more effective screening tests are introduced it appears necessary to stress the previous history of future blood donors in order to search for hepatitis C risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Donors↗
PubMed1982

Immunologic response in chickens from different genetic lines to Rous sarcoma virus.

Twelve young chickens of the Tumor Progressor and Tumor Regressor Lines were studied in respect to their humoral immunologic response to challenge with Rous sarcoma virus via inoculation into the wing web. On day 1, prior to virus inoculation and on days 10, 15, and 20 after injection of virus, the birds were bled and their serums tested for the presence of anti-RSV factors by standard procedures of serum-neutralization tests. From the conducting of statistical analyses of the data, it was determined that a strong association occurs between an early, increasing, and sustained presence of biologically active anti-RSV factors in the blood of the chicken and its ability to effect complete regression of the Rous sarcoma.

Animals↗
PubMed2000

[New findings on the ecology and epidemiology of murine herpes virus isolated in Slovakia].

Rodents are important reservoir animals of many human microbial pathogens. Of small rodents, trapped on Slovakia territory, were several strains of murine herpes virus (MHV) isolated. Our purpose was to complete the existing knowledge about circulation of MHV in rodents and to find out, whether also other animal species including man are MHV sensitive or not. The presence of antibodies against MHV in serum of the tested animals and men was followed by virus neutralization test (VNT) and ELISA. Pathological changes in differential white blood cell count of the trapped rodents, were also observed because it is known, that MHV induces them in laboratory mice. A total of 627 small terrestrial mammals of nine species were collected in four localities of western and eastern Slovakia during 1984-1988. Neutralizing antibodies to MHV were detected in five species of rodents in 130 cases (20.7%). Antibodies were most frequently detected in Apodemus flavicollis (34.9%). Pathological changes in differential white blood cell count of trapped rodents were detected in 37% (34/92). Neutralizing antibodies were found also in serum of fallow deers (Dama dama), wild boars (Sus scrofa), deers (Cervus elaphus) and sheep but not in serum of pheasants (Phasianus colchicus) and muflons (Ovis musimon). ELISA and VNT tests were used to investigate 20 serums of employees of the Institute of Virology, Slovak Academy of Sciences and Faculty of Natural Sciences of Comenius University. There were eight samples positive (40%). The titers of antibodies were 4-32 in VNT and 1000 in ELISA.

Animals↗