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Domínguez M, Moreno I, Toraño A. Quantitation of monoclonal antibody by capture ELISA based on initial enzyme activity rate. J Immunol Methods 2019; 474:112645. [PMID: 31404550 PMCID: PMC7094287 DOI: 10.1016/j.jim.2019.112645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/21/2019] [Accepted: 08/08/2019] [Indexed: 11/30/2022]
Abstract
We developed a noncompetitive two-site sandwich ELISA to quantitate monoclonal antibodies in culture supernatant. This assay measures the initial enzyme activity rate during the first minute of the reaction, which ensures linear velocity relative to time and a progress curve slope proportional to analyte concentration. During this period, the enzyme substrate is in large excess relative to the analyte/antibody-enzyme complex, and enzyme catalysis proceeds in steady-state conditions. Analyses of repeatability gave coefficients of variation between 4.4 and 9.7 (interassay) and 4.4 and 6.4 (intra-assay), and analyte detectability ranged from 5.8 to 12 ng/ml. The Z-factor calculated for analyte samples at their end dilution yielded mean values from 0.57 to 0.87, which confirmed assay robustness. This initial velocity-based sandwich ELISA is a simple, sensitive, reproducible method to quantitate bi-epitopic antigens. Antibody quantitation by measuring initial velocity of enzyme product formation Initial rate measurements ensure ELISA velocity proportional to analyte concentration. A mAb isotype-matched standard curve could reduce antiglobulin heterogenous reactivity.
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Affiliation(s)
- Mercedes Domínguez
- Unidad de Inmunología Microbiana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Inmaculada Moreno
- Unidad de Inmunología Microbiana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.
| | - Alfredo Toraño
- Unidad de Inmunología Microbiana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
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Han JI, Kang SY, Yoon KJ, Na KJ. Nucleic acid-based differential diagnostic assays for feline coronavirus. J Virol Methods 2014; 208:21-5. [PMID: 25088974 PMCID: PMC7113662 DOI: 10.1016/j.jviromet.2014.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 07/08/2014] [Accepted: 07/11/2014] [Indexed: 11/19/2022]
Abstract
A multiplex RT-PCR assay was developed to detect feline coronavirus. To improve primer binding, inosine was used for primer design. The assay could detect and differentiate FCoV, CCoV, and TGEV precisely.
Feline coronavirus (FCoV) is a pleomorphic, enveloped, positive-sense single-stranded RNA virus. Owing to the differences in its genotype, FCoV belongs to a separate clade along with other viruses, such as transmissible gastroenteritis virus (TGEV) and canine coronavirus (CCoV), which can be isolated from cats. In this study, a PCR assay was developed to differentiate these coronaviruses concurrently. Multiplex differential RT-PCR was performed with primers based on the highly conserved coronavirus membrane protein. Three primer sets were designed: a primer pair (S1 and S2) that can bind to conserved sequences in all target coronaviruses, a CCoV-specific primer (S3), and a TGEV-specific primer (S4). Because of the high sequence homology among FCoV, CCoV, and TGEV, a nucleotide preceding the last pair of dissimilar nucleotides in S3 and S4 was substituted with an inosine to allow primer binding. This assay could detect and differentiate FCoV (n = 7), CCoV (n = 4), and TGEV (n = 8) precisely and did not show any cross-reactivity with other pathogens. These results suggest that this molecular approach provides a rapid and reliable way to detect FCoV, especially in feline clinical specimens.
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Affiliation(s)
- Jae-Ik Han
- College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, South Korea; Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Shien-Young Kang
- College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, South Korea
| | - Kyoung-Jin Yoon
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Ki-Jeong Na
- College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, South Korea.
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3
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Miller DL, Taylor SK, Rotstein DS, Pough MB, Barr MC, Baldwin CA, Cunningham M, Roelke M, Ingram D. Feline immunodeficiency virus and puma lentivirus in Florida panthers (Puma concolor coryi): epidemiology and diagnostic issues. Vet Res Commun 2009; 30:307-17. [PMID: 16437306 PMCID: PMC7089169 DOI: 10.1007/s11259-006-3167-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2004] [Indexed: 11/14/2022]
Abstract
This study documents the seroprevalence of feline immunodeficiency virus (FIV) and puma lentivirus (PLV) in free-ranging and captive Florida panthers (Puma concolor coryi) (n = 51) and translocated Texas cougars (P. concolor stanleyana) (n = 10) from 1985 to 1998. The sera were tested for anti-FIV antibodies by enzyme-linked immunosorbent assay (ELISA) and Western blot tests. The ELISAs were read kinetically (KELA) and the sera were retrospectively examined by PLV peptide ELISA. Eleven panthers and one cougar were positive by KELA; 4 panthers and 4 cougars were equivocal; 35 panthers and 5 cougars were negative; and 1 panther had no data. Seven of the 11 KELA-positive panthers were also positive by Western blot tests and all but one were positive by PLV peptide ELISA. Ten KELA-negative and Western blot-negative cats, were positive by PLV peptide ELISA. KELA results varied within cats from one sample period to the next, but PLV peptide ELISA results were consistent. Territorial sympatry and mating behaviour, noted from radiotelemetry location data on the cats, may have contributed to viral transmission between seropositive animals. These findings suggest that Florida panthers and the introduced Texas cougars have been exposed to FIV and/or PLV.
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Affiliation(s)
- D L Miller
- Veterinary Diagnostic and Investigational Laboratory, College of Veterinary Medicine, University of Georgia, Tifton, Georgia 31793, USA.
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4
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Pratelli A. Comparison of serologic techniques for the detection of antibodies against feline coronaviruses. J Vet Diagn Invest 2008; 20:45-50. [PMID: 18182507 DOI: 10.1177/104063870802000108] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The seroprevalence of feline coronavirus (FCoV) antibodies was studied in cats in southern Italy. One hundred twenty sera collected from cats belonging to catteries or community shelters and to households were tested for FCoV type I and II antibodies. The virus neutralization (VN) was performed and compared with indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). Ninety-six sera tested positive for FCoV antibodies by VN and ELISA. Interestingly, ELISA revealed 2 more positive sera than did the VN test and 3 more positive sera than did the IFAT. All results were confirmed by Western blotting. ELISA proved to be more sensitive and detected a seroprevalence of about 82%. Considering the cross-reactivity of FCoV type I and type II, ELISA was able to detect antibodies against both serotypes, allowing the use of the assay as a reference test for sera screening. The high prevalence of antibodies observed indicates that FCoVs are common in southern Italian cat populations.
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Affiliation(s)
- Annamaria Pratelli
- Department of Animal Health and Well-being, Faculty of Veterinary Medicine of Bari, S.p. per Casamassima km 3, 70010 Valenzano, Bari, Italy.
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Kim KT, Murano EA, Olson DG. DEVELOPMENT OF AN ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) FOR ANALYSIS OF LISTERIOLYSIN O PRODUCED BY LISTERIA MONOCYTOGENES. ACTA ACUST UNITED AC 2007; 2:189-201. [PMID: 32313413 PMCID: PMC7159331 DOI: 10.1111/j.1745-4581.1993.tb00289.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/1993] [Indexed: 11/30/2022]
Abstract
Listeriolysin O (LLO) is a heat‐labile hemolysin produced by Listeria mono‐cytogenes. Its hemolytic activity has been evaluated qualitatively by sodium dodecyl sulfate (SDS) electrophoresis and immunoblotting. In this experiment, an enzyme‐linked immunosorbent assay (ELISA) was developed for quantitative analysis of LLO by using Streptolysin O (SLO) and antistreptolysin O (ASO) as the reagents. The selected coating and blocking buffers were 0.05 M Tris buffer (pH 8.5) and 0.25% casein solution with phosphate‐buffered saline solution + 0.05% Tween 20 (PBS‐T), respectively. A relationship between ASO and antibody was achieved with 5 mg/ml ASO and a 1:1,000 dilution of conjugate. The heat stability of LLO at 48, 62, 72, and 80C was examined by using this method and compared with a traditional hemolysis assay. Although the LLO is inactivated easily at those temperatures, the protein structure was not affected at temperatures lower than 80C for 3 min, pointing to a need for both hemolysis and ELISA to be conducted in determining both the activity and presence of LLO in foods.
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Affiliation(s)
- Kee-Tae Kim
- Department of Food Science and Human Nutrition
| | - Elsa A Murano
- Department of Microbiology, Immunology and Preventive Medicine and Department of Food Science and Human Nutrition
| | - Dennis G Olson
- Department of Animal Science and Department of Food Science and Human Nutrition Iowa State University, Ames, Iowa 50011
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Clifford DL, Mazet JA, Dubovi EJ, Garcelon DK, Coonan TJ, Conrad PA, Munson L. Pathogen exposure in endangered island fox ( Urocyon littoralis) populations: Implications for conservation management. BIOLOGICAL CONSERVATION 2006; 131:230-243. [PMID: 32226080 PMCID: PMC7096732 DOI: 10.1016/j.biocon.2006.04.029] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Island fox (Urocyon littoralis) populations on four California Channel Islands have declined severely since 1994. Canine distemper (CDV) was suspected to be responsible for the decline of the Santa Catalina Island fox, so knowledge of infectious disease exposure in the remaining island fox populations was urgently needed. This study reviewed previous pathogen exposure in island foxes and investigated the current threat by conducting a serologic survey of foxes on all islands and sympatric feral cats on three islands from 2001 to 2003 for antibodies against canid pathogens. Before the decline, foxes had evidence of exposure to CDV, canine adenovirus (CAV), canine parvovirus (CPV), and Toxoplasma, with exposure to these five pathogens differing greatly by island. Exposure to canine coronavirus (CCV), canine herpesvirus (CHV), and Leptospira was rare. In 2001-2003, wild-born foxes had evidence of exposure to CDV (5.2-32.8%) on 5 of 6 islands, CPV (28-100%) and CAV (4.7-100%) on five islands, and Toxoplasma gondii (2.3-15.4%) on four islands. Exposure to CCV, CHV and Leptospira was less common. Sharing of infectious agents between sympatric foxes and feral cats appeared minimal, but CDV exposure was detected in two cats on Santa Catalina Island. Domestic dogs have historically been present on the islands, but it is not known if canine diseases can be maintained in fox populations without the continual presence of dogs. Targeted vaccination programs against the most virulent pathogens and continued intensive disease surveillance may help protect the critically small remaining fox populations from disease outbreaks that could threaten the success of ongoing conservation efforts.
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Affiliation(s)
- Deana L. Clifford
- Wildlife Health Center, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Jonna A.K. Mazet
- Wildlife Health Center, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Edward J. Dubovi
- Diagnostic Laboratory, New York State College of Veterinary Medicine, Cornell University, PO Box 786, Ithaca, NY 14851, USA
| | | | - Timothy J. Coonan
- National Park Service, Channel Islands National Park, 1901 Spinnaker Drive, Ventura, CA 93001, USA
| | - Patricia A. Conrad
- Wildlife Health Center, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Linda Munson
- Wildlife Health Center, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
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Abstract
The article discusses feline infectious peritonitis (FIP), an important disease frequently seen in veterinary practice. FIP causes many problems to the veterinarian as it can be difficult to definitively diagnose the disease, as there is no effective treatment, and as prophylactic interventions are not very successful. Although intense research has created a lot of new knowledge about this disease in the last years, there are still many unanswered questions. The objective of this article is to review recent knowledge and to increase understanding of the complex pathogenesis of FIP.
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Affiliation(s)
- Katrin Hartmann
- Clinic of Small Animal Medicine, Ludwig-Maximilians-Universität München, Veterinaerstrasse 13, 80539 Munich, Germany.
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8
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Palmer MV, Whipple DL, Olsen SC, Jacobson RH. Cell mediated and humoral immune responses of white-tailed deer experimentally infected with Mycobacterium bovis. Res Vet Sci 2000; 68:95-8. [PMID: 10684765 DOI: 10.1053/rvsc.1999.0324] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The objective of this study was to improve the understanding of immune responses of whitetailed deer (Odocoileus virginianus) infected with Mycobacterium bovis. Ten mature, female, white-tailed deer were inoculated by intratonsilar instillation of 2 x 10(3)or 2 x 10(5)colony-forming units of M. bovis. Lymphocyte proliferation and humoral response to M. bovis PPD and the M. bovis protein, MPB70 were measured. Deer were tested for exposure to M. bovis by the comparative cervical skin test. Biopsy specimens of skin test sites were examined microscopically and immunohistochemically. The comparative cervical skin test correctly identified all M. bovis -inoculated deer as exposed to M. bovis. Lymphocyte proliferative responses to MPB70 were more consistent than responses to M. bovisPPD in M. bovis -inoculated deer. Antibody responses were more prominent in deer with disseminated disease than in deer with localised disease. The cellular components of delayed-type hypersensitivity reactions at skin test sites were similar to tuberculin reactions in other species. T lymphocytes of the gamma/delta phenotype were seen in increased numbers in M. bovisPPD injection sites.
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Affiliation(s)
- M V Palmer
- Zoonotic Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA 50010, USA
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Bélec L, Tévi-Bénissan C, Lu XS, Prazuck T, Pillot J. Local synthesis of IgG antibodies to HIV within the female and male genital tracts during asymptomatic and pre-AIDS stages of HIV infection. AIDS Res Hum Retroviruses 1995; 11:719-29. [PMID: 7576932 DOI: 10.1089/aid.1995.11.719] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Paired sera and cervicovaginal secretions or seminal fluids, obtained from HIV-1-infected, clinically asymptomatic women (n = 41) and men (n = 12), were investigated in order to test the hypothesis of a local synthesis of IgG to HIV in the female and male reproductive tracts. Anti-gp41 + p24 IgG was evaluated by an IgG immunocapture assay, and anti-gp160 IgG by an indirect ELISA. Estimation of anti-HIV IgG-specific activities was carried out after ponderal determination of total IgG and evaluation of anti-HIV IgG activity. IgG to gp41 + p24, as well as IgG to gp160, were specifically detected in all sera, cervicovaginal secretions, and seminal fluid samples from all tested HIV-1-infected subjects. The mean specific activities of IgG to gp41 + p24 in cervicovaginal secretions and in seminal fluids were about 33-fold (in women) and 16-fold (in men) that of the corresponding sera; similarly, the mean specific activities of IgG to gp160 in genital secretions were about 17-fold (in women) and 10-fold (in men) that of the corresponding sera. IgGs to HIV are constantly detected in genital secretions from HIV-1-infected subjects, and appear to be largely synthesized in situ within the genital tract of both genders.
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Affiliation(s)
- L Bélec
- Unité d'Immunologie Microbienne, Institut Pasteur, Paris, France
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Böse R, Peymann B. Diagnosis of Babesia caballi infections in horses by enzyme-linked immunosorbent assay (ELISA) and western blot. Int J Parasitol 1994. [PMCID: PMC7130175 DOI: 10.1016/0020-7519(94)90081-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
From Babesia caballi in vitro cultures a preparation of 100% infected erythrocytes was obtained. From this, B. caballi antigens were extracted with the detergent 3-[(3-Cholamidopropyl)-dimethylammonio]-1-propane-sulfonate (CHAPS) and used as ELISA antigens. A control antigen of normal erythrocytes from the same donor horse was prepared in an identical manner. The ELISA and Western blot were validated by testing of sera from horses experimentally infected with B. caballi or B. equi or not infected with Babesia spp. ELISA and Western blot results were compared with those obtained by the immunofluorescence antibody test (IFAT) and complement fixation test (CFT). The sensitivity of the ELISA of 98.3% obtained for sera from day 14 after infection was superior to the Western blot (94.9%), the IFAT (96.6%) and the CFT (28.8%). No positive results were obtained in the ELISA and Western blot with 106 sera from horses not infected with Babesia spp. resulting in a calculated specificity of 100% for both tests. Cross reactions of B. equi-positive sera did occur to a larger extent in the ELISA (20%) than in the IFAT (4%). No cross reactions were observed with the Western blot and the CFT. The higher sensitivity of the ELISA was also demonstrated by testing of 132 field sera: more positive results were obtained by ELISA (112) as compared to IFAT (92) or CFT (41). The validity of these results was confirmed by testing of sera by Western blot. The ELISA as the most sensitive test provides the best method for the identification of carrier horses to prevent the introduction into non-endemic areas (export testing). Positive ELISA results can be confirmed by Western blot, if a species-specific diagnosis is required.
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Böse R, Peymann B, Barbosa IP. Identification of diagnostic antigens for South American Babesia caballi infections. Int J Parasitol 1994; 24:255-8. [PMID: 8026903 PMCID: PMC7130368 DOI: 10.1016/0020-7519(94)90034-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Sera from 60 horses held in breeding herd in Brazil were examined monthly by ELISA, immunofluorescence antibody test (IFAT) and Western blot. All foals had maternal antibodies detectable by ELISA and IFAT, and sero-conversion took place between the 2nd and 5th month of age. The 48 and 50 kDa antigens were recognized first in the course of infection. Of 79 sera taken after sero-conversion 78 reacted with the 48 kDa antigen, 76 with the 50 kDa, 50 with the 70 kDa, 54 with the 112 kDa, 72 with the 141 kDa antigen. In general, sera from horses older than 1 year reacted with all 5 diagnostic antigen bands, but sera from horses older than 3 years only weakly. The antigens of 48 and 50 kDa appear to be conserved among all strains of B. caballi examined so far and are consistently recognized by all infected horses. They are the target antigens for a serological test based on antigens produced by recombinant DNA techniques.
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Affiliation(s)
- R Böse
- Institute of Parasitology, Hannover School of Veterinary Medicine, Bünteweg, Germany
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12
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Inokuma H, Kerlin RL, Kemp DH, Willadsen P. Effects of cattle tick (Boophilus microplus) infestation on the bovine immune system. Vet Parasitol 1993; 47:107-18. [PMID: 8493757 PMCID: PMC7131769 DOI: 10.1016/0304-4017(93)90181-l] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The immunosuppressive effect of experimental Boophilus microplus infestation on bovine peripheral blood lymphocytes (PBL) and on host antibody production to a protein antigen (ovalbumin) was examined. Boophilus microplus infestation caused a marginal decrease in the percentage of T lymphocytes in PBL, which was observed in both lightly (5000 larvae) and heavily (40,000 larvae) infested cattle, and began at the second infestation and continued until the end of the fourth infestation. The percentage of B lymphocytes in heavily tick-infested cattle was less than that in non-infested control cattle after the fourth infestation. The response of PBL from tick-infested cattle to phytohemagglutinin (PHA) was always less than that of tick-free cattle after the second infestation. No noteworthy differences were detected between the three stages of tick infestation, that is, 1 week before the peak of adult engorgement, the middle of the peak and 1 week after all ticks had dropped. Boophilus microplus saliva (100 microliters ml-1) suppressed 47% of the response of bovine PBL to PHA in vitro. This suppressive effect of saliva may contribute to the lower responsiveness of PBL from tick-infested cattle. Antibody production by tick-infested cattle was examined during the third and fourth heavy tick infestation. Tick-infested cattle showed a diminished response against ovalbumin after the second immunization. The immunosuppressive effects of tick infestation may play an important role in tick survival or in the transmission of tick-borne diseases in the field.
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Affiliation(s)
- H Inokuma
- National Livestock Breeding Center, Ministry of Agriculture, Forestry and Fisheries, Fukushima, Japan
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Lin DS, Bowman DD, Jacobson RH. Immunological changes in cats with concurrent Toxoplasma gondii and feline immunodeficiency virus infections. J Clin Microbiol 1992; 30:17-24. [PMID: 1346403 PMCID: PMC264990 DOI: 10.1128/jcm.30.1.17-24.1992] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To examine the immunological changes in cats concurrently infected with feline immunodeficiency virus (FIV) and Toxoplasma gondii, kittens (four per group) were inoculated with FIV, T. gondii, both agents, or no pathogens. Blood mononuclear cells and plasma were collected weekly for lymphocyte assays and serology. At week 14, spleen and lymph node cells were used for lymphocyte assays; brains and mesenteric lymph nodes were used for isolation of T. gondii. More T. gondii organisms were present in tissues of the dually infected cats than in tissues of cats with toxoplasmosis alone. Two dually infected cats and one cat infected with T. gondii developed chorioretinitis. Spleen, lymph node, and blood mononuclear cells from dually infected cats had the greatest reduction in mitogenic responses. By week 3, cats infected with FIV underwent a decrease in the number of CD4 cells that was not changed by concurrent T. gondii infection; the number of CD8 cells increased only in cats infected with T. gondii alone. For cats infected with T. gondii, the responses of lymphocytes to T. gondii antigen were not affected by FIV infection; the responses to FIV antigen were negligible in all groups. Overall, this study indicates that FIV infection favors T. gondii proliferation. Also, the establishment of toxoplasmosis may enhance FIV-induced immunodeficiency and is likely to cause a more rapid disease progression than that from infection with FIV alone.
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Affiliation(s)
- D S Lin
- Department of Microbiology, Immunology, and Parasitology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853-6401
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14
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Abstract
Cattle infested with the tick Boophilus microplus produce antibodies to intrinsic membrane glycoproteins of the tick, as well as to Bm86, a well characterized antigen from the tick gut. Several factors explain how cattle could produce antibody to such antigens, which one would expect to be 'concealed' from the host's immune system, during natural infestation. It has been shown that the carbohydrate determinants on many tick glycoproteins are cross-reactive immunologically and that the reaction of bovine antibodies with intrinsic membrane glycoprotein is at least partially blocked by low molecular weight carbohydrate. Further, antisera from cattle exposed to ticks react with a glycosylated, native Bm86 but not with a non-glycosylated, recombinant Bm86. Thus the reaction of concealed antigens with antibodies produced as a result of tick infestation appears to be due to a relatively non-specific reaction with carbohydrate determinants on tick glycoprotein. Evidence is also presented that antibodies directed against carbohydrate determinants of Bm86 are not protective. Care must therefore be exercised in interpreting the results of antibody reaction with glycoproteins in such complex organisms.
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Affiliation(s)
- P Willadsen
- CSIRO Division of Tropical Animal Production, Indooroopilly, Queensland, Australia
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15
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Lin DS, Lai SS, Bowman DD, Jacobson RH, Barr MC, Giovengo SL. Feline immunodeficiency virus, feline leukaemia virus, Toxoplasma gondii, and intestinal parasitic infections in Taiwanese cats. THE BRITISH VETERINARY JOURNAL 1990; 146:468-75. [PMID: 2171713 DOI: 10.1016/0007-1935(90)90037-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A population consisting of 70 breeder cats, 43 clinical cases, and 16 feral cats was examined for the presence of Toxoplasma gondii, feline immunodeficiency virus (FIV), and feline leukaemia virus (FeLV). No oocysts of T. gondii were observed in 96 faecal samples; faecal samples were not available from the feral cats. Other intestinal parasites identified included Isospora felis (three cats), Isospora rivolta (five), Dipylidium canium (two), Toxocara cati (four), Toxascaris leonina (one), and Ancylostoma sp. (two). Using a kinetics-based enzyme-linked immunosorbent assay on 117 sera including all the feral cats, nine had antibody to T. gondii antigen, three for antigens to FIV, and seven to the p27 antigen of FeLV. Of the nine cats with antibody to T. gondii, only one was also infected with FIV.
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Affiliation(s)
- D S Lin
- Department of Veterinary Microbiology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853
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16
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Hök K. Demonstration of feline corona virus (FCV) antigen in organs of cats suspected of feline infectious peritonitis (FIP) disease. APMIS 1990; 98:659-64. [PMID: 2168724 DOI: 10.1111/j.1699-0463.1990.tb04985.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cryosections of organs and smears from membrana nicitians from cats suspected of having spontaneous infection with feline infectious peritonitis virus (FIPV), were investigated using an indirect immunofluorescence assay (IIFA) in order to detect the presence of feline corona virus (FCV). In 113 cats, from each of which six organs were screened, virus antigen was found most often in membrana nicitians and lung. Out of these animals an additional six organs from a group of 30 cats were screened. In these cats membrana nicitians, parotid gland, thymus and apex of caecum had the highest incidence of virus antigen (90%). The lowest incidence of virus antigen was found in the spleen (60%). There was a clear demonstration of a higher incidence of antigen present in more than half of the total number of screened organs per cat (P less than 0.0005). No statistical difference was observed between sexes when comparing the incidence of virus antigen in different organs. Virus antigen was present in less organs in cats with no lesions suggestive of FIP disease compared to cats with such lesions (P less than 0.001). A similar distribution of the incidence of FCV antigen in the investigated organs was observed in these two groups.
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Affiliation(s)
- K Hök
- Depart. of Medical Microbial Ecology, Karolinska Institute, Stockholm, Sweden
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Böse R, Jacobson RH, Gale KR, Waltisbuhl DJ, Wright IG. An improved ELISA for the detection of antibodies against Babesia bovis using either a native or a recombinant B. bovis antigen. Parasitol Res 1990; 76:648-52. [PMID: 2251239 PMCID: PMC7088413 DOI: 10.1007/bf00931081] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Two new enzyme-linked immunosorbent assays (ELISA) for the diagnosis of Babesia bovis in cattle are described. The ELISA using a native antigen is more sensitive and less laborious than the assays described previously, because it does not require adsorption of sera with bovine erythrocytes. The second ELISA, using a recombinant B. bovis antigen expressed in Escherichia coli, was both sensitive and specific. It is suitable to replace the native antigen, thus avoiding large batch-to-batch variations in antigen preparations and the need to sacrifice experimental cattle.
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Affiliation(s)
- R Böse
- CSIRO Division of Tropical Animal Production, Long Pocket Laboratories, Indooroopilly, Queensland, Australia
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18
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Stoddart CA, Barlough JE, Baldwin CA, Scott FW. Attempted immunisation of cats against feline infectious peritonitis using canine coronavirus. Res Vet Sci 1989. [PMID: 2850601 PMCID: PMC7131371 DOI: 10.1016/s0034-5288(18)30970-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Specific pathogen free kittens were vaccinated with an unattenuated field isolate of canine coronavirus (CCV) either by aerosol or subcutaneously, and received boosting vaccinations four weeks later. Aerosolisation elicited a homologous virus-neutralising (VN) antibody response that increased steadily over a four-week period and levelled off one to two weeks after revaccination. The initial aerosolised dose produced an asymptomatic infection with excretion of CCV from the oropharynx up to eight days after vaccination; virus shedding was not detected, however, after the second inoculation. Cats vaccinated subcutaneously developed low VN antibody titres after the first CCV dose and experienced a strong anamnestic response after the second dose. Neutralising antibody titres then levelled off one to two weeks after revaccination at mean values somewhat lower than in cats vaccinated by aerosol. CCV was not isolated from the oropharynx after either subcutaneous dose. Four weeks after CCV boosting inoculations, vaccinated cats and sham-vaccinated control cats were divided into three subgroups and challenged by aerosol with the virulent UCD1 strain of feline infectious peritonitis virus (FIPV UCD1) at three different dosage levels. Five of six cats (including sham-vaccinated controls) given the lowest challenge dose showed no signs of disease, while all other cats developed lesions typical of feline infectious peritonitis (FIP). The five surviving cats developed FIP after subsequent challenge with a fivefold higher dose of FIPV. Thus heterotypic vaccination of cats with CCV did not provide effective protection against FIPV challenge.
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Affiliation(s)
- C A Stoddart
- Cornell Feline Health Center, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853-6401
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19
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Mochizuki M, Furukawa H. An enzyme-linked immunosorbent assay using canine coronavirus-infected CRFK cells as antigen for detection of anti-coronavirus antibody in cat. Comp Immunol Microbiol Infect Dis 1989; 12:139-46. [PMID: 2558837 PMCID: PMC7134073 DOI: 10.1016/0147-9571(89)90062-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
From the reasons that canine coronavirus (CCV) grows more efficiently than feline coronavirus in a cell culture and they are mutually related in their antigenicities, an enzyme-linked immunosorbent assay (ELISA) using CCV-infected feline kidney (CRFK) cells as substrate antigens was developed for detection of anti-coronavirus antibodies in cats. It was indispensable for generating coronavirus-specific ELISA antibody activities that the sample was applied to the mock-infected, normal CRFK cells in parallel with the CCV-infected cells and then the optical density values given by the mock-infected cell antigen were subtracted from those given by the virus-infected cell antigen. On the basis of ELISA antibody titers obtained in sera from the cats experimentally infected with CCV and from the spontaneous feline infectious peritonitis (FIP) cases, the ELISA described in the present study was found to be applicable as a simple and easy serologic test which was able to detect anti-coronavirus antibodies as efficiently as the indirect immunofluorescence assay with homologous FIP virus.
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Key Words
- coronavirus
- feline infectious peritonitis virus
- canine coronavirus
- enzyme-linked immunosorbent assay
- elisa
- virus de la péritonite infectieuse féline
- coronavirus canin
- test immunopenzymatique
- ccv, canine coronavirus
- crfk, crandell feline kidney
- dk/p, primary dog kidney
- eagle's mem, eagle's minimal essential medium
- elisa, enzyme-linked immunosorbent assay
- fecv, feline enteric coronavirus
- fip, feline infectious peritonitis
- fipv, fip virus
- ifa, indirect immunofluorescence assay
- mab, monoclonal antibody
- mnt, micro-neutralization test
- nus, nu-serum
- od, optical density
- pfu, plaque forming unit
- pbs, phosphate buffered saline solution
- tgev, transmissible gastroenteritis virus
- vnt, virus neutralization test
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Affiliation(s)
- M Mochizuki
- Department of Veterinary Medicine, Faculty of Agriculture, Kagoshima University, Japan
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20
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Snyder MH, Banks S, Murphy BR. Determination of antibody response to influenza virus surface glycoproteins by kinetic enzyme-linked immunosorbent assay. J Clin Microbiol 1988; 26:2034-40. [PMID: 3182992 PMCID: PMC266811 DOI: 10.1128/jcm.26.10.2034-2040.1988] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We modified an existing enzyme-linked immunosorbent assay (ELISA) to be able to use new spectrophotometers which can measure the rate of color development in microtiter wells. This new kinetic-based ELISA (KELISA) required only a single dilution of specimen rather than the multiple dilutions required with endpoint ELISA. In addition, 10- to 100-fold-less specimen was required to perform the KELISA than the ELISA. The level of serum or nasal wash antibody against surface glycoproteins of influenza A or influenza B viruses determined by KELISA was reproducible and correlated highly with the results of endpoint ELISA or hemagglutination inhibition tests. The difference between the KELISA rates, which indicated than an antibody response to infection had occurred, was defined and was analogous to a 2.2-fold rise in titer for serum and a 3.4-fold rise in titer for nasal wash determined by endpoint ELISA. The KELISA was similar to endpoint ELISAs in its ability to detect rises in antibody level in paired serum or nasal wash specimens obtained from volunteers who received live attenuated influenza A reassortant virus vaccines. By eliminating the need for multiple dilutions, the use of KELISA offers the advantage of increasing the number of assays that can be performed by the same personnel compared with endpoint ELISA, while it maintains sensitivity and specificity.
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Affiliation(s)
- M H Snyder
- Laboratory of Infectious Diseases, National Institute of Allergy, Infectious Diseases, Bethesda, Maryland 20892
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21
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Nielsen KH, Wright PF, Kelly WA, Cherwonogrodzky JH. A review of enzyme immunoassay for detection of antibody to Brucella abortus in cattle. Vet Immunol Immunopathol 1988; 18:331-47. [PMID: 3137720 PMCID: PMC7133660 DOI: 10.1016/0165-2427(88)90160-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/1987] [Indexed: 01/04/2023]
Abstract
Enzyme immunoassay has gained wide acceptance for serological diagnosis of bovine brucellosis because of its ability to detect antibody of all isotypes unlike the conventional tests. The indirect enzyme immunoassay, however, presents several parameters that require careful analysis. These parameters include the choice of antigen and antiglobulin-enzyme conjugate reagents for use in the assay, dealing with the large amount of data the semi-automatic or automatic assay can generate and the inter- and intralaboratory standardization and quality control. This review considers the various methods described in the literature and, briefly, how some of the problems have been overcome or how they might be dealt with.
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Affiliation(s)
- K H Nielsen
- Agriculture Canada, Animal Diseases Research Institute, Nepean, Ont., Canada
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22
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Ross SM, Reynolds CP. Collection and analysis of complex ELISA data using a microcomputer. JOURNAL OF IMMUNOASSAY 1987; 8:319-31. [PMID: 3680533 DOI: 10.1080/15321818708057031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A system for automatic Enzyme-Linked Immunosorbent Assay (ELISA) data collection and processing is described. Hardware for the system consists of a Dynatech microplate reader and Apple II series microcomputer. Software developed by the authors allows automatic configuration of the reader and direct data input from the microplate reader to the microcomputer. After optical density data is input through the interface, it can be printed out as either optical density values, or as scaled values (from 0 to 9) in a color-coded matrix. Data can be stored and later recalled in either format, allowing several sets of data to be merged into one large, color-coded chart. Results from several different microplates can be combined and sorted in a single printout to expedite interpretation of data.
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Affiliation(s)
- S M Ross
- Immunobiology and Transplantation Department, Naval Medical Research Institute, Bethesda, MD 20814-5055
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23
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Barlough JE, Jacobson RH, Downing DR, Lynch TJ, Scott FW. The kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats: calibration to the indirect immunofluorescence assay and computerized standardization of results through normalization to control values. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 1987; 51:56-9. [PMID: 3032390 PMCID: PMC1255274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The computer-assisted, kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats was calibrated to the conventional indirect immunofluorescence assay by linear regression analysis and computerized interpolation (generation of "immunofluorescence assay-equivalent" titers). Procedures were developed for normalization and standardization of kinetics-based enzyme-linked immunosorbent assay results through incorporation of five different control sera of predetermined ("expected") titer in daily runs. When used with such sera and with computer assistance, the kinetics-based enzyme-linked immunosorbent assay minimized both within-run and between-run variability while allowing also for efficient data reduction and statistical analysis and reporting of results.
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24
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Scott FW. Immunization against feline coronaviruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1987; 218:569-76. [PMID: 2829570 DOI: 10.1007/978-1-4684-1280-2_72] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Feline infectious peritonitis (FIP) is caused by one of several strains of feline coronaviruses which are grouped into 2 general types of viruses. Infection of cats with FIP virus results in production of serum antibodies which may be protective in conjunction with cell mediated immunity, may provided no protection at all, or may produce an immune enhancement to subsequent exposure to another FIP virus or a recrudescence of the original infecting virus. Attempts at immunization of cats against FIP with inactivated or live FIP viruses have been generally unsuccessful, and often sensitizing the cat through immune enhancement rather than providing protection. Heterologous live virus vaccines using viruses of the same antigenic cluster (transmissible gastroenteritis of swine, canine coronavirus, and human coronavirus 229E) have failed to provide protection against FIP virus. Further research into the exact mechanism of protection and immune enhancement is needed in order to understand ways of producing an effective and safe vaccine.
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Affiliation(s)
- F W Scott
- Department of Veterinary Microbiology, Immunology and Parasitology, College of Veterinary Medicine, Cornell University, Ithaca, New York
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25
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Hancock K, Tsang VC. Development and optimization of the FAST-ELISA for detecting antibodies to Schistosoma mansoni. J Immunol Methods 1986; 92:167-76. [PMID: 3760581 DOI: 10.1016/0022-1759(86)90162-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The Falcon assay screening test (F.A.S.T.) system was used to develop a rapid, sensitive, and quantitative kinetic-based enzyme-linked immunosorbent assay (k-ELISA) for detecting antibodies against Schistosoma mansoni adult microsomal antigens (MAMAs). The FAST-ELISA uses polystyrene beads on sticks molded to the lid of a microtitration plate. The beads are coated with antigen. Reagents and sera are placed in microtitration plates and the beads exposed to reagents by immersion. The exposure time required for a single dilution of serum or other antibody source, conjugate, and substrate is 5 min each. Excluding preparation time, two plates can easily be assayed in 30 min. The optima for assay conditions, reproducibility, quantitative linearity, and sensitivity are delineated. A battery of sera from patients with both homologous and heterologous infections was tested, and a dilution series of a standard reference serum pool was included with each test. Results were expressed in number of units as calibrated against the standard reference sera pool. Antigen-coated bead storage studies were performed with untreated and three chemically treated antigens. The storage stability of MAMA, ability to perform the assay with minimal equipment, sensitivity, short assay time, and ease of operation make the FAST-ELISA ideal for field studies.
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26
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Fiscus SA, Teramoto YA, Mildbrand MM, Knisley CV, Winston SE, Pedersen NC. Competitive enzyme immunoassays for the rapid detection of antibodies to feline infectious peritonitis virus polypeptides. J Clin Microbiol 1985; 22:395-401. [PMID: 2995437 PMCID: PMC268418 DOI: 10.1128/jcm.22.3.395-401.1985] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Monoclonal antibodies specific for the envelope (E1), peplomer (E2), and nucleocapsid (N) polypeptides of feline infectious peritonitis virus (FIPV) were used in rapid, competitive enzyme-linked immunosorbent assays (ELISA) to study the humoral immune response of cats to FIPV infection. Results from the competitive ELISAs were correlated with those from immunofluorescent antibody assays (IFAs) on 203 samples obtained from 64 individual cats. The IFA results correlated best with those obtained with the anti-E1 specific competitive ELISA (85.7%). In contrast, anti-N and anti-E2 competitive ELISA results correlated with IFA results only 65.5 and 2.4% of the time, respectively. The results of the anti-E1 specific competitive ELISA were not influenced by the total immunoglobulin concentration or the possible presence of free viral antigens in the serum. These results suggest that a competitive ELISA involving the use of enzyme-conjugated monoclonal antibody to the E1 glycoprotein of FIPV is a simple and rapid replacement for the more cumbersome IFA.
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27
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Barlough JE, Johnson-Lussenburg CM, Stoddart CA, Jacobson RH, Scott FW. Experimental inoculation of cats with human coronavirus 229E and subsequent challenge with feline infectious peritonitis virus. CANADIAN JOURNAL OF COMPARATIVE MEDICINE : REVUE CANADIENNE DE MEDECINE COMPAREE 1985; 49:303-7. [PMID: 2994865 PMCID: PMC1236175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Minimal-disease cats exposed to live human coronavirus 229E developed homologous antibody responses that suggested little or no replication of the virus in inoculated animals. Oronasal and subcutaneous inoculation of coronavirus 229E did not elicit an antibody response by heterologous (transmissible gastroenteritis virus, canine coronavirus) neutralization or by heterologous (transmissible gastroenteritis virus) kinetics-based enzyme-linked immunosorbent assay. No clinical signs attributable to coronavirus 229E were seen in inoculated cats. Although the number of animals in each of the five experimental groups was small (n = 2), antibodies produced in response to the virus did not appear to sensitize cats to subsequent feline infectious peritonitis virus challenge, but neither did they cross-protect cats against the challenge dose.
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28
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29
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Timoney PJ, Shin SJ, Lein DH, Jacobson RH. Transmissibility of the contagious equine metritis organism for the cat. Comp Immunol Microbiol Infect Dis 1984; 7:131-40. [PMID: 6548676 PMCID: PMC7134161 DOI: 10.1016/0147-9571(84)90007-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A group of SPF cats were moderately susceptible to the causal organism of contagious equine metritis (CEM) following intra-uterine or intrapreputial challenge with an Irish streptomycin resistant strain isolated from a clinically infected mare. Subclinical infections were established in only 50% of the cats, none of which became long-term carriers of the organism. Cytological examination of vaginal smears was of no diagnostic value in confirming infection in inapparently infected cats. Bacteriological responses after primary or secondary challenge with the CEM organism were essentially similar, with one exception, a female cat in which there was possible evidence of local immunity persisting after the primary infection. Efforts to reactivate shedding subsequent to the immediate post-challenge period were unsuccessful. Throughout the experimental period, the cats remained sero-negative to the complement-fixation test, and they failed to develop any significant increase in the levels of antibody activity as measured by the kinetics-based ELISA or KELA system. On day 89 after primary challenge, the cats were euthanized and various sites in the genitourinary tract and the internal iliac lymphatic glands subjected to bacteriological and pathological examination for evidence of CEM infection with negative results. The findings of this study, although establishing the transmissibility of the CEM organism for the cat, demonstrate the limited value of this species as an experimental model system for the disease in the horse.
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30
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Barlough JE. Serodiagnostic aids and management practice for feline retrovirus and coronavirus infections. Vet Clin North Am Small Anim Pract 1984; 14:955-69. [PMID: 6093322 PMCID: PMC7134470 DOI: 10.1016/s0195-5616(84)50101-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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31
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Tsang VC, Hancock K, Maddison SE. Quantitative capacities of glutaraldehyde and sodium m-periodate coupled peroxidase-anti-human IgG conjugates in enzyme-linked immunoassays. J Immunol Methods 1984; 70:91-100. [PMID: 6325546 DOI: 10.1016/0022-1759(84)90393-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Covalently linked peroxidase-anti-human IgG conjugates were prepared by either glutaraldehyde or NaIO4 coupling techniques. Sodium dodecyl sulfate polyacrylamide gel electrophoresis shows that the glutaraldehyde coupled conjugate is composed of generally lower molecular weight components than the NaIO4 coupled product. The NaIO4 conjugate, when used to quantitate human immunoglobulin (Ig) in enzyme-linked immunoassays, appears to be highly sensitive in that small amounts of Ig elicited relatively high reactivities. The quantitative range of this type of conjugates, where reactivities are linearly proportional to the amount of human Ig present, is, however, extremely narrow (0.01-0.10 micrograms/ml of human IgG). Conversely, the glutaraldehyde coupled type conjugate is capable of sustaining a much wider range of linearity (0.01-0.6 micrograms/ml), but with a more gradual rise of reactivity which corresponds well to the amount of human Ig present. Conjugates prepared with glutaraldehyde are thus more useful in quantitative assays where wide quantitative ranges are desirable. NaIO4 conjugates on the other hand, are more suited to qualitative assays where sensitivity is more important.
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32
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Franco EL, Walls KW, Sulzer AJ, Campbell GH, Roberts JM. Computer-assisted multiple categorization of absorbance values in ELISA through pictorial emulation of 96-well plates. J Immunol Methods 1984; 70:45-52. [PMID: 6371149 DOI: 10.1016/0022-1759(84)90388-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A simple algorithm is proposed by which multiple categorization of absorbance values from ELISA plates is performed under a microcomputer control. The printed output is a pictorial emulation of a 96-well plate with the color intensities represented for each reaction. Although the method is presented as a colorimeter computer interfaced system, a provision for manual entry of absorbance values via keyboard is also included. Simulation is based solely on the magnitude of absorbance values. Therefore, it is possible to utilize any enzyme/substrate combination within the range of filters of the colorimeter. We have tested the present system for titration of anti-malarial antibodies in human serum and for the screening of mouse hybridoma culture supernatants.
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33
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Barlough JE, Jacobson RH, Pepper CE, Scott FW. Role of recent vaccination in production of false-positive coronavirus antibody titers in cats. J Clin Microbiol 1984; 19:442-5. [PMID: 6325494 PMCID: PMC271086 DOI: 10.1128/jcm.19.3.442-445.1984] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Statistical support was obtained for an association between recent vaccination of cats and the presence of elevated background (i.e., anti-cell culture) reactivity in certain of their sera, as detected with a kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies, implicating routine vaccination as a potential cause of false-positive antibody test results.
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34
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Mathews HM, Walls KW, Huong AY. Microvolume, kinetic-dependent enzyme-linked immunosorbent assay for amoeba antibodies. J Clin Microbiol 1984; 19:221-4. [PMID: 6321547 PMCID: PMC271025 DOI: 10.1128/jcm.19.2.221-224.1984] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We describe a microvolume enzyme-linked immunosorbent assay based on enzyme rate kinetics. Antigens from Entamoeba histolytica were adsorbed in wells of disposable polystyrene strips containing 12 flat-bottom wells. After exposure to the serum of a patient and peroxidase-labeled anti-human immunoglobulin G, the rate of color change in specific substrate was determined by eight sequential readings of individual wells over a 2-min period with a microcomputer-controlled model MR-600 automated plate reader. The changes in absorbance readings were converted to slope values for each well by the microcomputer. Thus, 12 samples were read, and results were printed in ca. 3.5 min. Assay conditions are described and data are presented to show that this assay is quantitative for antibody and antigen concentration with a single-tube (well) dilution.
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35
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36
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Stoddart CA, Barlough JE, Scott FW. Experimental studies of a coronavirus and coronavirus-like agent in a barrier-maintained feline breeding colony. Arch Virol 1984; 79:85-94. [PMID: 6320773 PMCID: PMC7086742 DOI: 10.1007/bf01314306] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Minimal-disease (MD) cats raised in a barrier-maintained feline breeding colony routinely become coronavirus (CV) antibody-positive at 5-8 weeks of age and remain seropositive indefinitely. In addition, they shed coronavirus-like particles (CVLPs) in their feces which are morphologically distinct from "typical" coronaviruses. Oronasal, intraperitoneal, intraduodenal, and intravenous inoculations of CVLPs were uniformly unsuccessful in the seroconversion of cats to CV, whereas subsequent prolonged close contact with colony cats did result in seroconversion. Such evidence indicates that MD cats in this barrier colony are infected with at least two non-crossreactive agents: (1) feline enteric CVLPs, which are shed in feces and are morphologically and antigenically distinct from established coronaviruses (CVs), and (2) a virus which is antigenically cross-reactive with CVs, but which is apparently shed by some route other than the lower gastrointestinal tract.
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37
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Winter AJ, Verstreate DR, Hall CE, Jacobson RH, Castleman WL, Meredith MP, McLaughlin CA. Immune response to porin in cattle immunized with whole cell, outer membrane, and outer membrane protein antigens of Brucella abortus combined with trehalose dimycolate and muramyl dipeptide adjuvants. Infect Immun 1983; 42:1159-67. [PMID: 6315592 PMCID: PMC264420 DOI: 10.1128/iai.42.3.1159-1167.1983] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The immune response of cattle to nonliving vaccines derived from Brucella abortus rough strain 45/20 was studied. Vaccines contained trehalose dimycolate and a derivative of muramyl dipeptide. N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine. A factorial experiment was designed to test the effects of type of antigen, quantity of antigen, and quantity of mineral oil on the immune response to porin. Muramyl dipeptide was kept constant at 5 mg per dose, and 1 part of trehalose dimycolate was incorporated for two parts of dry matter. Over a 10-week period, blastogenesis responses to porin were largest in cattle immunized with outer membranes; the highest antibody titers to the porin-lipopolysaccharide complex were achieved by immunization with detergent-extracted outer membrane proteins. There was no advantage in the use of 25, rather than 5, mg of any of the antigens, but antibody responses were improved by increasing the quantity of oil from 0.6 to 1.8 ml per dose. In other animals, blastogenesis and antibody responses were sustained at high levels longer than 3 months after two vaccinations with outer membrane proteins. Intradermal injection of porin evoked inflammatory reactions histologically consistent with delayed-type hypersensitivity. Cross-reactions in cases of delayed-type hypersensitivity occurred with porin derived from a smooth strain of B. abortus but were less extensive than in the blastogenesis test. The magnitude of the delayed-type hypersensitivity and blastogenesis responses induced by vaccination exceeded those observed after natural or experimental infections. No ill effects were observed after vaccination. These findings provide a basis for the use of trehalose dimycolate and muramyl dipeptide adjuvants in evaluating nonviable vaccines for bovine brucellosis.
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