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PubMed1978

Cross reaction between bovine enterovirus and South African Territories I5 foot-and-mouth disease virus.

A bovine enterovirus (E76T) isolated from a 2-year-old bull produced serologic cross reactions to South African Territories (SAT) I5 foot-and-mouth disease virus when inoculated into guinea pigs and cattle. Cross-reacting serum titers to SAT I5 virus of 1:320 by the plaque-reduction neutralization test and 1:20 by the radial immunodiffusion test occurred in 2 steers after they were inoculated with the E76T virus. In 1 steer, maximal cross-reacting titers appeared related to a 2nd exposure to the viruses or to a hyperimmune state. Ultracentrifugation and 2-mercaptoethanol studies indicated that the cross reactions were due to immunoglobulin M antibody. Sera from guinea pigs immunized with the E76T or the SAT I5 virus cross reacted with the heterologous virus by postinoculation day 7. Cross-reacting titers had decreased markedly by postinoculation day 35, whereas the homologous virus titer remained constant. Cross reactivity of the E76T virus was primarily with the SAT I5 virus, and to a lesser degree with SAT II3. Cross reactions did not occur with representatives of the 5 other antigenic types of foot-and-mouth disease virus.

Animals↗
PubMed2005

Genetic variation and cross-reactivity of Clostridium septicum alpha-toxin.

Clostridium septicum alpha-toxin genes were sequenced with the polymerase chain reaction (PCR) products amplified from DNAs of 25 C. septicum strains, and were classified into 10 patterns. Alpha-toxins were purified from the culture supernatant of four C. septicum strains (strains No. 44, Kagoshima 8, Mie and Tokachi) which were specially chosen from patterns of the deduced amino acid sequences. The molecular weights of the alpha-toxins were not different according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. However, the isoelectric points between the alpha-toxins of No. 44 and Tokachi strains differed markedly. Cross-neutralization tests were performed with purified alpha-toxins and antitoxins in mice and in Vero cells. Each antitoxin showed roughly the same titers against the four alpha-toxins in mice and completely identical titers against these in Vero cells. Calves immunized with toxoid prepared from the culture supernatant of No.44 strain were challenged by exposure to spores of Mie strain. The toxoid conferred protection against the challenge in calves. From these results, although genetic variation has been observed within the C. septicum alpha-toxin gene, C. septicum strains toxoid of strain No.44 induces protective immunity against exposure to C. septicum that produce other subtypes of alpha-toxin containing several different amino acid residues.

Amino Acid Sequence↗
PubMed1996

Liquid-phase blocking sandwich enzyme-linked immunosorbent assay for detection of antibodies against foot-and-mouth disease virus in water buffalo sera.

OBJECTIVE: To develop and apply the liquid-phase blocking sandwich ELISA (BLOCKING-ELISA) for the quantification of antibodies against foot-and-mouth disease virus (FMDV) strains O1 Campos, A24 Cruzeiro, and C3 Indaial. DESIGN--Antibody quantification. SAMPLE POPULATION: 158 water buffalo from various premises of Sao Paulo State-Brazil. The sera were collected either from systemically vaccinated or nonvaccinated animals. PROCEDURE: The basic reagents of BLOCKING-ELISA (capture and detector antibodies, virus antigens, and conjugate) were prepared and the reaction was optimized and standardized to quantify water buffalo antibodies against FMDV. An alternative procedure based on mathematical interpolation was adopted to estimate more precisely the antibody 50% competition titers in the BLOCKING-ELISA. These titers were compared with the virus-neutralization test (VNT) titers to determine the correlation between these techniques. The percentages of agreement, cutoff points, and reproducibility also were determined. RESULTS: The antibody titers obtained in the BLOCKING-ELISA had high positive correlation coefficients with VNT, reaching values of 0.90 for O1 Campos and C3 Indaial, and 0.82 for the A24 Cruzeiro (P < 0.0005). The cutoff points obtained by use of the copositivity and conegativity curves allowed determination of high levels of agreement between BLOCKING-ELISA and VNT antibody titers against the 3 FMDV strains analyzed. CONCLUSIONS: The results characterized by high correlation coefficients, levels of agreement, and reproducibility indicate that the BLOCKING-ELISA may replace the conventional VNT for detection and quantification of antibodies from water buffalo sera to FMDV.

Animals↗
PubMed1992

Identification of four VP4 serological types (P serotypes) of bovine rotavirus using viral reassortants.

A series of five reassortant viruses each containing the VP4 gene of a distinct bovine rotavirus and the VP7 gene of human rotavirus strain ST3 was prepared, and antisera to these were produced in rabbits. In neutralization tests, these antisera allowed the differentiation of the five original strains (from three different VP7 or G serotypes) into three or possibly four VP4 or P serotypes. All of a further seven bovine rotavirus strains adapted to cell culture were successfully typed by these antisera. There was a degree of cross-reaction between antiserum to the fourth bovine rotavirus P serotype and the predominant human rotavirus serotype. However, antisera raised in guinea-pigs to recombinant VP4 from this serotype showed the bovine serotype to be distinct. There was no significant serological relationship between these four bovine rotavirus P serotypes and previously described P serotypes from rotaviruses isolated from man and non-bovine animals. The predominant bovine rotavirus VP7 serotypes G6 and G10 tended to have distinct P serotypes also.

Animals↗
PubMed2004

Occurrence of equine coital exanthema in pastured draft horses and isolation of equine herpesvirus 3 from progenital lesions.

During the period from 2001 to the following year, progenital diseases had been epidemic among the draft stallions and mares pastured together in Iwate Prefecture, the northeastern district of Japan. A stallion and 8 of 31 mares were affected in 2001, and 1 of 2 stallions and 10 of 36 mares in 2002. The clinical symptoms consisted of the formation of papules, pustules, ulcers and scabs on the progenital skin and mucosa in stallions and mares. In 2002, Equine herpesvirus 3 (EHV3) was isolated from 2 mares and the glycoprotein G gene of the virus detected from a stallion and 4 mares by polymerase chain reaction. Serum neutralizing tests showed that 12 of 38 horses, 10 clinically and 2 subclinically affected, changed to be positive for the EHV3 antibody. The results suggest that the horses were affected with equine coital exanthema (ECE) through coitus. Five mares with the antibody at the pre-pastured period may have been the possible origins of EHV3 infection in 2002, although the exact origin in 2001 remains unknown. The artificial insemination was performed for the prevention of ECE spreading through coitus on the pasture in 2003. There was no epidemic of the disease in 31 mares, although 3 mares with the antibody at the pre-pastured period showed the significant increase in the titers during the pastured period.

Animals↗
PubMed1998

The protective effect of Clostridium novyi type B alpha-toxoid against challenge with spores in guinea pigs.

Clostridium novyi (C. novyi) Type B alpha-toxin was purified from culture supernatant by column chromatography, and was inactivated by formalin. A purified alpha-toxoid vaccine was prepared by mixing it with an aluminum phosphate gel adjuvant. Guinea pigs immunized twice with 4 micrograms or more of alpha-toxin survived against challenge with C. novyi Type B spores. Anti-alpha-toxin (antitoxin) titer was measured by toxin neutralization test using Vero cells. All of the guinea pigs having antitoxin titers of 10 units (U) or more at challenge were survived. In another experiment, guinea pigs were immunized with crude alpha-toxoid vaccines prepared by inactivated culture supernatant or by adding broken bacterial cells to the former. In this experiment, 10 U of antitoxin titer was the border of survival or death after challenge. Guinea pigs with antitoxin titers of less than 5 U, 5 U and 10 U died at 2, 3 to 4 and 4 days, respectively, after challenge. These results suggest that C. novyi alpha-toxin was the main protective antigen against challenge exposure to spores in guinea pigs.

Animals↗
PubMed2005

Serologic survey of cats and dogs during an epidemic of West Nile virus infection in humans.

OBJECTIVE: To estimate West Nile virus (WNV) infection rates, assess environmental variables that correlated with seropositivity in dogs and cats, and assess whether pets should be considered as possible sentinels for WNV and therefore of potential human exposure. DESIGN: Cross-sectional serosurvey. ANIMALS: 442 dogs and 138 cats. PROCEDURE: Serum samples were screened for seropositivity against WNV by use of the plaque reduction neutralization test. RESULTS: 116 (26%) dogs and 13 (9%) cats yielded positive results. The odds of seropositivity against WNV for outdoor-only family dogs were almost 19 times as great as those for indoor-only family dogs and almost twice as great for stray dogs as for family dogs. Family dogs not receiving heartworm medication were 2.5 times as likely to yield positive results for antibodies against WNV as family dogs receiving heartworm medication. CONCLUSIONS AND CLINICAL RELEVANCE: Seropositivity was greater for outdoor family dogs than for indoor family dogs. Further investigation of the potential use of stray dogs as sentinel indicators for WNV infection and the potential risk of human exposure is warranted.

Animal Husbandry↗
PubMedDate not supplied

Development and evaluation of an ELISA for the detection of antibody to infectious laryngotracheitis virus in chickens.

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibody to infectious laryngotracheitis (ILT) virus in chickens was developed and compared with the serum-neutralization assay. The ELISA routinely yielded 16-to-32-fold higher titers than the serum-neutralization test. To overcome the requirement for large amounts of purified viral antigen, the microtiter trays were initially coated with an antibody prepared against purified ILT virus. A relatively crude viral preparation could then be used to coat the trays. Sera from specific-pathogen-free chickens less than 12 weeks of age did not show nonspecific binding, although 2.7% of all sera from chickens between 13 and 64 weeks of age had nonspecific activity. The majority of nonspecific reactors came from one highly inbred flock of specific-pathogen-free chickens. A number of modifications of ELISA procedures reported to reduce the nonspecific binding of chicken sera were investigated. Treatment of the serum or the plate and changes in the composition of the diluent did not increase the relative sensitivity of the anti-ILT assay.

Animals↗
PubMed2002

Economical multi-site intradermal regimen with purified chick embryo cell vaccine (Rabipur) prevents rabies in people bitten by confirmed rabid animals.

OBJECTIVE: To determine the efficacy of a cost-effective multi-site intradermal regimen with purified chick embryo cell vaccine (PCECV, Rabipur) in preventing rabies in people bitten by confirmed rabid dogs. METHODS: Thirty-two people of different age groups who were severely bitten by confirmed rabid dogs were immunized with PCECV using the WHO recommended multi-site intradermal regimen of 0.1 mL of vaccine at eight sites on day 0, at four sites on day 7, and at one site each on days 28 and 90. In addition, passive immunization with human or equine rabies immunoglobulin was administered to 22 of these people before administering vaccine. They were followed for up to 3 years with periodic estimation of neutralizing antibody levels in their serum by mouse neutralization test (MNT). RESULTS: There was an excellent immune response with more than protective titers (>0.5 IU/mL) on all days tested up to the end of the 3-year observation period. More significantly, protective titers were seen in all subjects by day 7. Only minimal side effects were observed. All the patients were doing well at the end of the 3-year observation period, which is generally considered to be the maximum incubation period for rabies in humans. CONCLUSIONS: It can be concluded that this multi-site regimen with or without passive immunization has prevented the development of rabies encephalitis in these people bitten by confirmed rabid dogs. This should encourage more such studies, so that this cost-effective economical regimen with safe and potent cell culture vaccines can replace highly reactogenic neural tissue-derived Semple vaccine in developing countries such as India.

Adolescent↗
PubMedDate not supplied

[Study of the antigenic relationship of different strains of the rabies group viruses].

In neutralization tests in animals close antigenic relationship between human virus of acute encephalomyelitis (AEM) and viruses (297 and 598 SG strains) isolated from wild rodents in Czechoslovakia was first established. At the same time, poor antigenic relationship of human AEM virus to viruses isolated in Africa from bats (Lagos bat) and from shrews (YbAn 27377) was demonstrated. Certain differences in the antigenic properties of viruses isolated in Africa and in Czechoslovakia were found. These studies indicate the existence of many varieties in the rabies virus group. Ferther accumulation of data concerning different viruses of the rabies group is necessary as they may be helpful for elucidation of the pathology of certain neuroinfections due to viruses of this group as well as for creation of the necessary collection of the investigated strains for preparation of rabies vaccines.

Africa↗
PubMed1996

Reverse transcription-polymerase chain reaction amplification of respiratory syncytial virus genome from neonatal nasal swab samples.

In order to make a rapid and accurate diagnosis of respiratory syncytial virus (RSV) infection, nasal swabs obtained from 14 neonates suspected of having this disease were examined for the presence of RSV genome by reverse transcription (RT) and nested polymerase chain reaction (PCR) amplification, along with enzyme immunoassay (EIA), serum neutralization testing and virus isolation. The RT-PCR method was sensitive enough to detect a 0.1 50% tissue culture infectious dose (TCID50) per milliliter by nested PCR. The RSV antigen was detected from the samples at more than 100 TCID50 per milliliter by EIA. Nine patients were positive for the presence of RSV genome by first PCR on the day of admission, and eight were also positive by nested PCR even on the fifth hospital day. Among nine PCR positives, four patients were positive for EIA and five for virus isolation. No cases were serologically diagnosed. The cases that were negative for RT-PCR were also negative according to the other methods. In the clinical setting, the RT-PCR assay is more useful for diagnosis of RSV infection than other methods when the suspected cases are negative by EIA assay.

Female↗
PubMed1978

OK 10 virus, an avian retrovirus resembling the acute leukaemia viruses.

The OK 10 virus complex was isolated from a liver tumour of a chicken which, as an embryo, had been inoculated intravenously with a field isolate of an avian leukosis virus. The OK 10 virus complex contains at least two viruses: the interference assay and serum neutralization test indicate that the helper virus belongs to subgroup A. One of the viruses, OK 10 V, induces distinct foci in chick embryo cells under agar overlay and cells from the foci form colonies in soft agar. These properties allow in vitro assay of the virus. Injection of virus or infected cells into chicks induces acute leukaemia but no local tumours. Another virus, OK 10 AV (associated virus), comprises about 99% of the OK 10 complex. The virus does not induce foci in chick embryo cells. In chickens it causes leukosis 17 months after injection. Electron micrographs of OK 10 virus stocks show typical C type virus particles. These particles have a density of 1.16 g/ml and contain 70S RNA which, after heat denaturation, releases type b RNA subunits. The OK 10 virus complex apparently represents a strain of acute leukaemia viruses.

Alpharetrovirus↗
PubMed2000

Effects of bovine herpesvirus type 1 infection in calves with maternal antibodies on immune response and virus latency.

The presence of maternally derived antibodies can interfere with the development of an active antibody response to antigen. Infection of seven passively immunized young calves with a virulent strain of bovine herpesvirus type 1 (BHV-1) was performed to determine whether they could become seronegative after the disappearance of maternal antibodies while latently infected with BHV-1. Four uninfected calves were controls. All calves were monitored serologically for 13 to 18 months. In addition, the development of a cell-mediated immune response was assessed by an in vitro antigen-specific gamma interferon (IFN-gamma) production assay. All calves had positive IFN-gamma responses as early as 7 days until at least 10 weeks after infection. However, no antibody rise was observed after infection in the three calves with the highest titers of maternal antibodies. One of the three became seronegative by virus neutralization test at 7 months of age like the control animals. This calf presented negative IFN-gamma results at the same time and was classified seronegative by enzyme-linked immunosorbent assay at around 10 months of age. This calf was latently infected, as proven by virus reexcretion after dexamethasone treatment at the end of the experiment. In conclusion, this study demonstrated that BHV-1-seronegative latent carriers can be obtained experimentally. In addition, the IFN-gamma assay was able to discriminate calves possessing only passively acquired antibodies from those latently infected by BHV-1, but it could not detect seronegative latent carriers. The failure to easily detect such animals presents an epidemiological threat for the control of BHV-1 infection.

Aging↗
PubMedDate not supplied

Molecular characterization of an infectious bronchitis virus strain isolated from an outbreak in vaccinated layers.

An infectious bronchitis virus (IBV) strain CT/7852/97 was isolated from a commercial layer flock experiencing decreased egg production and poor egg quality. Reciprocal virus neutralization test demonstrated that the isolate was closely related to Massachusetts, Arkansas, and JMK. With the use of both reverse transcription-polymerase chain reaction-restriction fragment length polymorphism and multiplex polymerase chain reaction methods, results consistently showed that CT/7852/97 isolate was Massachusetts serotype specific only. The nucleotide sequence of S1 polypeptide coding region of CT/7852/97 was determined and compared with the published sequences of 12 IBV strains from North America. The highest nucleotide homology with H120 (97%) and the least homology (62%) with Delaware (De/072/92) were observed. Massachusetts 41 and Beaudette shared 94% and 93%, respectively, nucleotide similarity with CT/7852/97, and Connecticut, JMK, and Arkansas 99 had 94%, 83%, and 78%, respectively, nucleotide similarity with CT/7852/97. Furthermore, no possible recombination site on S1 gene among Massachusetts 41, Arkansas 99, and JMK was detected in the isolate.

Amino Acid Sequence↗
PubMed2005

Identification of new flaviviruses in the Kokobera virus complex.

Novel flavivirus isolates from mosquitoes collected in northern Australia were analysed by partial genomic sequencing, monoclonal antibody-binding assays and polyclonal cross-neutralization tests. Two isolates were found to be antigenically distinct from, but related to, viruses of the Kokobera virus complex, which currently contains Kokobera (KOKV) and Stratford (STRV) viruses. Nucleotide sequence comparison of two separate regions of the genome revealed that an isolate from Saibai Island in the Torres Strait in 2000 (TS5273) was related closely to KOKV and STRV, with 74-80 and 75-76 % nucleotide similarity, respectively. An isolate from mainland Cape York in 1998 (CY1014) was found to be more divergent from KOKV and STRV, with <70 % nucleotide sequence similarity to either virus. It is proposed that isolate TS5273 represents a new subtype of KOKV and that CY1014 be classified as a novel species within the Kokobera virus complex of flaviviruses, named New Mapoon virus.

Animals↗
PubMed1992

The prevalence of types I and II feline coronavirus infections in cats.

The types of feline coronaviruses that are prevalent throughout Japan were determined by competitive enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody (MAb) to feline infectious peritonitis virus (FIPV) Type II and neutralizing test using Type II FIPV as challenge virus. A total of 1,079 cat serum samples were tested by indirect fluorescent antibody (IFA) assay for FIPV Type II antigen, all 42 sample from natural cases of FIP, 138 of 647 (21.3%) from cases with some chronic diseases and 57 of 390 (14.6%) from apparently non-diseased cases were positive. Of the 42 cases with FIP, 29 (69%) and 13 (31%) were found to have infection with FIPV Types I and II, respectively. Of the cases with chronic diseases, 111 (80.4%) were shown to have infection with FIPV or FECV Type I, while 14 (10.1%) with FIPV or FECV Type II. All of the 57 apparently non-diseased cases seemed to have been infected with FIPV or FECV Type I. These results indicated that feline coronavirus Type I is more high prevalent in Japan.

Animals↗
PubMed2004

Isolation and molecular identification of echovirus 13 isolated from patients of aseptic meningitis in Korea, 2002.

During 2002, several epidemics of aseptic meningitis were attributed to echovirus 13 in Korea. The causative agents of these outbreaks were isolated and identified using rhabdosarcoma cells, HEp-2 and Buffalo green monkey kidney cells, and a neutralization test using monospecific antiserum. Fifty-four echovirus 13 isolates were isolated from patients with aseptic meningitis in the provinces, Seoul, Kyonggi, Gwangju, Jeonju, Busan, and Ulsan. Symptoms associated with aseptic meningitis infection in patients included the occurrence of headaches and mild fever. Molecular characterization of echovirus 13 samples was achieved by sequence and phylogenetic analyses on partial VP1 sequences from 20 Korean isolates and 10 foreign isolates listed in Genbank. Minor variation was observed among the Korean isolates, which formed a unique cluster with isolates of German and Japanese origin. The marked similarities between isolates could be attributed to a relatively recent arrival of the virus in Korea. This is the first such investigation of aseptic meningitis caused by echovirus 13 on the Korean peninsula.

Animals↗
PubMed1992

Relationship between the anti-FMD virus antibody reaction as measured by different assays, and protection in vivo against challenge infection.

The antibody response of cattle after vaccination against foot-and-mouth disease (FMD) virus was monitored using the serum neutralization test (SNT), the sandwich ELISA, liquid-phase ELISA, sandwich competition ELISA, liquid-phase competition ELISA, and the liquid-phase sandwich competition (blocking) ELISA. The competition ELISAs (in particular the "blocking" ELISA) were the most effective at detecting reactivity in these cattle sera. However, 95% of negative sera also competed in the most sensitive ELISA (the "blocking" ELISA) to titres of 1:32 (4% of the sera competed to a titre of 1:128). Comparisons between the different ELISAs, and between these ELISAs and the SNT, demonstrated that the tests were not measuring exactly the same reaction of antibody with FMD virus. With respect to the capacity of animals to resist FMD virus challenge, neither the SNT nor the competition ELISAs were consistently able to identify such animals. The anti-FMD virus antibody titres obtained could be classified into three zones; the "white zone" wherein antibody titres were high and donor animals likely to be protected; the "black zone" wherein antibody titres were low and donor animals likely to be susceptible to infection; the "grey zone" wherein the antibody titres were intermediary and no interpretation could be made with respect to protection. Assays such as ELISA and SNT cannot and do not measure immunological protection; they are a measure of antibody responses and nothing more, and should be interpreted in terms of the "three zone" phenomenon.

Animals↗

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