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1.
The serological reactivity in indirect ELISA of five different bluetongue virus (BTV) serotypes (4, 10, 15, 16 & 20) was compared using polyclonal antisera raised against virus particles and an outer structural protein, VP2. Rabbit and sheep antisera against BTV-10 produced higher ELISA values with their homologous antigens than with heterologous serotypes. A hyperimmune rabbit serum specific for virus particles was able to distinguish heterologous serotypes from each other, but a sheep serum from an infected animal was not. An antiserum directed against VP2, the protein responsible for serotype specificity in neutralization tests, was not serotype-specific in ELISA and cross-reacted with other serotypes. The discriminatory ability of a BTV-4 antiserum was improved by cross-absorption with heterologous antigens. This greatly reduced the ELISA signals with heterologous serotypes and produced an antiserum that was effectively serotype-specific.  相似文献   

2.
Three monoclonal antibodies (MABs) reactive against two structural proteins--the nucleoprotein (NP) or the surface (S) protein--of avian infectious bronchitis virus (IBV) were produced and characterized. The MABs did not neutralize virus infectivity or inhibit hemagglutination. Their reactivity patterns with the homologous strain and eight heterologous strains of IBV were determined using the indirect immunoperoxidase test, the indirect immunofluorescent test, transfer-immunoblotting of separated proteins, and a dot-immunoblotting assay (DIA). Two MABs, NP- or S-protein-specific, reacted with all nine strains; one (NP-specific) reacted with only two strains. The two MABs reacting with all nine strains of IBV also detected 18 IBV field isolates of unknown serotype in the DIA. The MAB detecting only two strains did not react in the DIA. The diagnostic application of these MABs appears promising.  相似文献   

3.
Avian infectious bronchitis virus (IBV) causes tremendous economic losses to the poultry industry worldwide. Different serotypes of this virus show little cross-protection. The present study investigated the genotypic relationship between CK/CH/LDL/97I-type strains and reference IBVs based on S1 gene comparisons and the protection provided by vaccination with commercial vaccines and attenuated homologous and heterologous strains. Phylogenetic analysis and the comparison of S1 showed that CK/CH/LDL/97I-type virus might be a new serotype compared to vaccine strains and other types of IBV isolates in China. Protection efficacy was evaluated by morbidity, mortality, and virus re-isolation from the challenged chicks. Complete protection by IBV vaccination was provided by the homologous strain but sufficient respiratory protection was not provided by the commercial vaccines. Heterologous strains against CK/CH/LDL/97I challenge and the development of a vaccine against CK/CH/LDL/97I-type IBV will be necessary to control infectious bronchitis disease in poultry. Further development of the attenuated CK/CH/LDL/97I strain may provide a valuable contribution towards this goal.  相似文献   

4.
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5.
Cross-protection tests with homologous and heterologous serotypes of infectious bronchitis virus (IBV) were used to compare ciliary activity and virus recovery from tracheas of chickens. Validation of this technique included correlating the neutralization indices of antiserum obtained from some infected birds. Chickens were inoculated intratracheally with either the JMK or Connecticut (Conn) serotype of IBV. Three weeks later, infected and uninfected groups were challenged by the same route with homologous and heterologous virus. The JMK strain provided immunity against homologous challenge and the Conn strain, as indicated by good ciliary activity and lack of challenge virus recovery. The Conn strain provided only homologous protection, as ciliostasis occurred and virus was recovered after challenge with the JMK strain. In each case, antiserum to immunizing virus neutralized only the homologous virus. Controls were uniformly susceptible and lacked neutralizing antibody. A similar experiment with the Ark 99 serotype and a recent isolate (397) of IBV revealed complete cross-protection of the tracheas. Antiserum to each virus neutralized the homologous and heterologous virus in each case in reciprocal tests. The results indicate that these two viruses are closely related. The complete agreement between ciliary activity and virus isolation indicates that ciliary activity is a reliable, objective criterion upon which tracheal immunity can be judged in cross-protection tests.  相似文献   

6.
Antigenic relationship of Actinobacillus (Haemophilus) pleuropneumoniae serotype-8 isolates with other serotypes was studied, using tube agglutination, with and without 2-mercaptoethanol, indirect hemagglutination with and without 2-mercaptoethanol, ring precipitation, coagglutination, and immunodiffusion tests. Serotype-8 isolates possessed serotype-specific, group-specific common antigens cross-reactive with serotypes 3 and 6 and species-specific common antigens cross-reactive with other serotypes. Absorption studies were done to study the antigenic relationship of serotype 8 with serotypes 3 and 6. Rabbit antisera against whole-cell (WC) suspensions of reference strains of serotypes 3, 6, and 8 were used for absorption studies with WC and boiled WC suspensions of homologous and heterologous serotypes. Unabsorbed and absorbed sera were tested for antibodies against WC and boiled WC antigen preparations of serotype 8, using various serotests. Absorption studies revealed that serotype-8 strains possessed 2 main types of epitopes, one of which was serotype-specific and did not have cross-reactivity with other serotypes. The second type of epitopes was group specific and was cross-reactive with serotypes 3 and 6.  相似文献   

7.
The object in this investigation was to determine the relationship between protective activity and antigenic structure of Haemophilus paragallinarum, serotypes 1 and 2. A close relationship exists in both serotypes between protective activity and colonial phenotypic form (iridescent and noniridescent). Protective activities of both serotypes were related to a heat-labile, trypsin-sensitive (L) antigen of iridescent form that produced serotype-specific agglutinin to chickens. The chickens having the agglutinins were protected against challenge exposure with homologous strain, but not with heterologous strain. The chickens injected with unencapsulated organisms of noniridescent form that were derived from encapsulated organisms of iridescent form failed to produce both serotype-specific agglutinins and protection against challenge exposure with homologous strain. Most of the chickens injected with serotype 1 strain produced both hemagglutination-inhibition antibody and serotype 1-specific agglutinin, whereas those injected with serotype 2 produced serotype 2-specific agglutinin and protected against homologous challenge exposure. The protective activity was found in saline extract derived from encapsulated organisms of serotype 1, but was absent in those of serotype 2.  相似文献   

8.
Broiler minibreeder hens were used to produce monovalent antisera to bacterins prepared from serotypes 1, 3, 4, and 3 X 4 cross (CU strain) of P. multocida and to a polyvalent fowl cholera bacterin containing serotypes 1, 3, and 4. Antiserum to the CU strain (live vaccine) was also produced. Monovalent enzyme-linked immunosorbent assay (ELISA) plate antigens were prepared by separately sonicating each of the strains. Polyvalent plate antigen (Poly 3) was prepared by combining, in equal amounts after sonication, antigens from serotypes 1, 3, and 4. Each antiserum was assayed against its homologous ELISA plate antigen and against all other heterologous plate antigens, including Poly 3. The strongest reactions, as indicated by the highest absorbance values, were observed in homologous ELISAs. The CU strain may be the best monovalent ELISA plate antigen for detecting antibodies formed in response to a commercial polyvalent bacterin and to vaccinations with the live CU strain. Overall, monovalent serotype 1 (strain X-73) antiserum did not react well with any other heterologous ELISA plate antigen, whereas monovalent antisera of serotypes 4 (strain P-1662) and 3 X 4 (CU strain) reacted equally strongly with monovalent serotype 4 ELISA plate antigen. Background binding of negative serum was significantly lower (P less than 0.05) when using CU plate antigen than when using any of the other plate antigens.  相似文献   

9.
The antigenic differences between strains of serotype 2 of both biotypes I and II of Actinobacillus pleuropneumoniae were studied by using several serological techniques. Monoclonal antibodies (MAbs) against A. pleuropneumoniae biotype I serotype 2 were produced by fusion of spleen cells of BALb/c mice immunized with whole-cell (WC) suspension with SP2/O-Ag14 murine myeloma cells. Desirable MAbs were selected by enzyme-linked immunosorbent assay (ELISA) using WC as antigen. MAbs MK-7 and MK-10 identified multiple bands of lipopolysaccharide in Western-blot. Treatment of WC with proteinase K and sodium periodate indicated that both MAb binding sites were carbohydrates in nature. In both ELISA and Western-blot, MAbs MK-7 and MK-10 recognized only biotype I serotype 2 isolates. Neither MAb MK-7 nor MK-10 reacted with reference strains of remaining serotypes of A. pleuropneumoniae and other Gram-negative bacteria tested. The results obtained with various serological tests showed that strains of serotype 2 biotype I shared antigenic determinants with strain N-282 of serotype 2 biotype II, but not with strain N-273 of serotype 1 biotype II. It is suggested that data obtained from this study may be helpful in the development of specific serotyping and serodiagnostic reagents of A. pleuropneumoniae strains.  相似文献   

10.
Ibaraki virus, which causes a bluetongue-like disease of cattle in Japan, was compared antigenically with the four serotypes of bluetongue virus (BTV) found in the U.S. and with the two serotypes of epizootic hemorrhagic disease virus (EHDV). No antigenic relationship was found between Ibaraki virus and BTV serotypes 10, 11, 13, and 17 in tests for group or serotype-specific antigens. However, Ibaraki virus and EHDV were related antigenically. The agar gel precipitin and indirect fluorescent antibody tests for group antigens showed two-way cross relationships between Ibaraki virus and EHDV serotypes 1 and 2. The more restrictive serotype-specific neutralization test revealed that antigenic relatedness was stronger between Ibaraki virus and the serotype 2 (Alberta strain) of EHDV than between Ibaraki virus and the serotype 1 (New Jersey strain) of EHDV.  相似文献   

11.
For the identification of serotype-specific antigens of Marek's disease virus (MDV) serotype 1 (MDV1) or serotype 2 (MDV2), a total of 24 hybridoma clones, secreting monoclonal antibodies (MAbs) against CVI-988 (MDV1) or HPRS-24 (MDV2) strain, were established and characterized by immunofluorescence assay, virus neutralization and immunoprecipitation analysis. Based upon the molecular weights (mol. wt.) of the immunoprecipitated polypeptides, the MAbs were subdivided into 7 groups. Among them, two groups of MAbs reacted with antigens that have not been reported, were identified. MAbs belonging to the first group reacted with CVI-988- and MDV2-specific antigens with mol. wt. ranging from 29 K to 34 K (29/34 K). This antigen was not found in cells infected with Md/5 and JM strains of MDV1, and the results of kinetic analysis of antigen expression showed this antigen appeared to be related to late membrane antigens. MAbs belonging to the second group immunoprecipitated MDV2-specific antigens with mol. wt. of 37 K, 33 K and 31 K from HPRS-24-infected cells or with those of 37 K, 34 K and 31 K from SB-1(MDV2)-infected cells, and these antigens appeared to be related to early antigens. MAbs belonging to the other 5 groups included those which recognized similar antigens reported previously or the antigens characterized insufficiently in this study.  相似文献   

12.
Infectious bronchitis virus (IBV) causes respiratory disease in chickens all over the world. IBV has many serotypes that do not confer cross protection against each other. Hemagglutination inhibition (HI) test has been used to determine the serotypes of IBV as a substitute to the more laborious virus neutralization test and the more sophisticated restriction endonuclease digestion or sequencing of the S1 gene. In Jordan, no previous studies have been carried out to determine the involvement of IBV in respiratory disease in chickens, or the serotypes of IBV that possibly exist. In this study, serum from different chicken flocks (n = 20) that suffered from respiratory disease were tested for IBV antibodies using commercial IBV antibody ELISA at time of the initial signs of the respiratory disease and repeated on serum samples from the same flocks 10–14 days later. ELISA titer for IBV increased in 14 out of 20 flocks (70%) after 10–14 days of the initial signs of the respiratory disease and this indicates a recent exposure to IBV. The second serum samples from these 14 flocks were further examined against a panel of five IBV antigens (Ark, Conn, DE-072, JMK, and Mass) by HI test to determine the serotype(s) of IBV they have been exposed to. The HI test results indicated that the exposure of some of these flocks were to Ark, DE-072, and Mass like serotypes. However, the HI titers against the antigens used in this study were relatively similar in 10 out of the 14 flocks (71%) and the serotype of IBV that these flocks were exposed to could not be determined and the possible causes of this are discussed.  相似文献   

13.
Two monoclonal antibodies (MAbs), lMAb-1 and lMAb-5, against Actinobacillus pleuropneumoniae serotype 1 were obtained. In enzyme-linked immunosorbent assay-inhibition tests with whole cell antigens obtained from serotype 1 to 12 strains of A. pleuropneumoniae, lMAb-1 reacted to only a serotype 1, strain 4074. The epitope recognized by lMAb-1 was a carbohydrate sensitive to periodate oxidation and resided on capsular polysaccharide (CP) of A. pleuropneumoniae serotype 1. On the other hand, lMAb-5 reacted with serotype 1, 9 and 11 strains at the same degree and its epitope was found to be located on O-polysaccharide of serotype 1, 9 or 11 lipopolysaccharide (LPS). These results showed that CP was one of the serotype-specific antigens of A. pleuropneumoniae, and that O-polysaccharide of LPS obtained from serotype 1, 9 or 11 strain was the cross-reacting antigen among these strains.  相似文献   

14.
Capsular polysaccharides (CPS) of serotypes 1, 2, 5 and 7 of Actinobacillus (Haemophilus) pleuropneumoniae were obtained from 18 h culture supernatants by precipitation with hexadecyltrimethyl-ammonium bromide (Cetavlon) followed by extraction with sodium chloride and reprecipitation in ethanol. These crude extracts, and portions purified further by phenol extraction to remove contaminating proteins, were evaluated as antigens for the detection of serotype-specific antibodies to A. pleuropneumoniae in sera from immunized rabbits and swine by an enzyme-linked immunosorbent assay. The crude extracts reacted strongly with homologous antisera, but except for serotype 1 showed considerable cross-reactivity with antisera to other serotypes. Phenol extraction greatly improved the serospecificity of the antigens from serotypes 1, 7 and, to a lesser extent, 5. The serotype 2 CPS antigen showed poor reactivity following phenol extraction, and did not appear as useful for detection of serotype-specific antibodies.  相似文献   

15.
Haemophilus pleuropneumoniae serotypes--cross protection experiments   总被引：19，自引：0，他引：19  
Pigs vaccinated with a killed 6-hour culture of Haemophilus pleuropneumoniae serotype 2 with Freund's incomplete adjuvant were not protected against challenge with serotypes 1, 5, 6 or 8. Equivalent results were obtained when pigs were vaccinated with serotypes 4 or 5 and challenged with serotype 2. In earlier studies of immunity induced by intranasal immunization with live H. pleuropneumoniae organisms, it was clearly shown that intranasal inoculation with one serotype of H. pleuropneumoniae would induce a strong immunity to both homologous and heterologous serotypes (Nielsen 1979). The present study has shown that cross immunity is not obtained with parenteral immunization. The results strongly suggest that the immune response of the pig to parenteral vaccination is different from the response seen after natural infection, and indicate that an important part of the defence mechanism against H. pleuropneumoniae infection is a local immune-barrier which is effective in preventing the bacterium from penetrating the mucosa. In earlier vaccination experiments 90 per cent of vaccinates were protected against homologous challenge (Nielsen 1976). In the present work a vaccine containing serotypes 1 through 6 was fully protective against serotypes 2 and 3 and also against serotype 8, which shares antigenic determinants with serotypes 3 and 6. These results indicate that the protection obtained by parenteral immunization is serotype-specific. Vaccines must therefore contain the serotypes existing in the swine population.  相似文献   

16.
We used slot blot hybridization of the hypervariable regions of the S1 subunit of spike peplomer gene to identify and characterize infectious bronchitis virus (IBV) strains. Template DNA was created from six reference strain IBVs of different serotypes and immobilized on a nitrocellulose membrane. We synthesized digoxigenin-labeled probes from reference and unknown field viruses and hybridized them to template DNA. All reference strains could be distinguished and isolates identified by serotype if they were at least 95% identical to a reference strain. This slot blot hybridization procedure was specific and reproducible, and strain typing was consistent with the S1 sequencing of the IBV genome. This study thus provides a simple and rapid method for typing of IBV.  相似文献   

17.
The cross-reactivity of the purified polysaccharides of Actinobacillus pleuropneumoniae serotypes 1 and 9 were examined using a variety of highly sensitive assays, such as radioimmunoassay, latex agglutination, enzyme-linked immunosorbent assay (ELISA), and immunoblotting. In addition, conventional immunodiffusion was included for comparison. Latex agglutination, utilizing affinity-purified IgG to capsule, was also used to serotype whole cells. Agglutination or precipitation tests (radioimmunoassay, latex agglutination, and immunodiffusion) indicated no cross-reactivity between the capsules of serotypes 1 and 9, and no cross-reactivity between whole cells by latex agglutination. Assays that required binding of the capsule to a solid support (ELISA and immunoblotting) did demonstrate cross-reactions between serotypes 1 and 9 capsules, although reactions with the heterologous serotype were weaker than with the homologous serotype. The cross-reactivity could not be attributed solely to nonspecific factors because similar cross-reactivity did not occur with serotype 5 or 7 capsules by any assay. Reactivity of antisera with homologous or heterologous capsule was reduced, but not completely eliminated, by adsorption with washed, live bacteria of the heterologous serotype. Thus, the assay, as well as the antigen or specificity of the antibody reagent used, may influence the results of A. pleuropneumoniae serotyping or serological tests.  相似文献   

18.
A stable recombinant fowl poxvirus (rFPV) expressing the C-terminal region (119 amino acids) of the nucleocapsid (N) protein of an infectious bronchitis virus (IBV) strain Ch3 was constructed by inserting the coding sequence within the thymidine kinase gene of fowl poxvirus (FPV) by homologous recombination. The N protein was expressed under control of the vaccinia virus promoter P7.5 in chicken embryo fibroblast cell cultures as seen in immunofluorescence assay and in rFPV-inoculated specific-pathogen-free (SPF) chickens by detecting antibodies with enzyme-linked immunosorbent assay (ELISA). A homologous IBV strain (Ch3) and two heterologous IBV strains (Ch5 and H4) were used to inoculate SPF chickens in a challenge to examine the protective efficacy of the rFPV. When the chickens were challenged with IBV Ch3 or Ch5, the control birds had respiratory signs of infections bronchitis, whereas all the vaccinated birds were clinically normal although low levels of the IBV infection were detected by a differential ELISA. In contrast, in the chickens challenged with IBV H4, all control birds and vaccinated birds suffered from the highly lethal IBV H4 infection. Our results suggest that the C-terminal 119 amino acid of the nucleocapsid expressed by FPV is a host-protective antigen and may induce cross-protective immunity against illness among some IBV strains.  相似文献   

19.
A panel (26) of monoclonal antibodies (MAbs) was elicited against three distinct isolates of foot-and-mouth disease virus (FMDV) serotype Asia-1. Each MAb was characterized according to the location of its epitope: Class I, restricted to the intact virion (140S); Class II, restricted to 140S and the virion protein subunit (12Sps); Class III, available on 140S, 12Sps and virus protein 1; Class IV, restricted to 12Sps. In addition, the MAbs were further categorized by isotype, neutralization of viral infectivity, capacity to bind in radioimmunoassay and precipitation in the Ouchterlony reaction. Neutralization of FMDV infectivity by a MAb of the IgA isotype is reported for the first time. A minimum of seven distinct neutralization epitopes were described on FMDV Asia-1. Some of the neutralizing MAbs bound FMDVs in addition to those that they neutralized. The MAbs defined epitopes common to FMDV serotypes Asia-1, A, O1 and C but neutralizing capacity was restricted to serotype Asia-1. Class IV MAbs defined epitopes highly conserved throughout the FMDV serotypes. Identification of FMDV neutralization epitopes makes possible the direct selection of optimal FMDV strains for vaccine fabrication. In addition, these data are crucial to the design of future synthetic vaccines.  相似文献   

20.
A panel of six monoclonal antibodies (MAbs) produced from mice immunized with Pasteurella multocida (M1404) (Heddleston serotype 2) reacted with homologous lipopolysaccharide, as indicated by enzyme immunoassay and immunoblotting. All six MAbs reacted with serotypes 2 and 5 of the 16 Heddleston serotypes. The reactive epitopes were localized on the bacterial cell surface by immunogold labelling. The antibodies could agglutinate P. multocida only if cells were first treated with 1 N HCl. All six MAbs opsonized P. multocida for phagocytosis by mouse macrophages but were not bactericidal in the presence of complement. They afforded only partial protection against infection in mice. The results, together with those of active immunization experiments with LPS, suggest a subordinate role for LPS in protection from experimental infection in mice.  相似文献   

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