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An indirect fluorescent antibody test for the detection of antibody to swine infertility and respiratory syndrome virus in swine sera. 总被引：27，自引：0，他引：27
I J Yoon H S Joo W T Christianson H S Kim J E Collins R B Morrison G D Dial 《Journal of veterinary diagnostic investigation》1992,4(2):144-147
An indirect fluorescent antibody (IFA) test was developed and standardized to detect and quantitate antibody for swine infertility and respiratory syndrome (SIRS) virus in swine sera. Test results were evaluated using sera of pigs infected both experimentally and naturally with SIRS virus. The IFA test used swine alveolar macrophage (SAM) monolayers prepared in 96-well microplates and infected with SIRS virus. The monolayers were incubated with test sera, washed, and stained with fluorescein isothiocyanate-labeled rabbit anti-swine IgG. After another wash step, the monolayers were examined under a fluorescent microscope. A noninfected SAM control well was included for each sample. The antibody titers for each serum sample were recorded as the highest serum dilutions with specific cytoplasmic fluorescence but no fluorescence in the control wells. To evaluate the test, sera of 4 6-week-old pigs that had been infected with SIRS virus, 2 contact pigs, and 13 experimentally infected sows were used. In the experimentally infected pigs, antibody was first detected at 7 days postexposure (PE) and peaked (1:256-1,024) between 11 and 21 days PE. All 13 sow sera were negative at time of infection but were positive (1:64- greater than or equal to 1:1,024) at 14-26 days PE. Seven hundred twenty sera collected from 25 different swine farms with or without a history of SIRS were also tested. Of 344 sera from 15 swine farms with a clinical history of SIRS, 257 (74.7%) sera had IFA titers greater than or equal to 1:4, whereas 371 (98.7%) of 376 sera from herds with no history of SIRS were negative.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Antibodies against Theileria sergenti and Babesia ovata were detected by indirect fluorescent antibody (IFA) and complement fixation (CF) methods. Both of the antibodies against T. sergenti and B. ovata could be detected with a single IFA testing procedure. Complement fixing antibody tests for T. sergenti in experimentally infected cattle were positive for about 70 days after the parasites could no longer be detected in the blood smear, and were negative thereafter. B. ovata CF antibody titres were negative on the 270th day post-infection, while the IFA tests against both parasites were positive for longer periods. B. ovata IFA-test titres remained relatively high until the 420th day after inoculation. In a survey of sera from naturally infected animals, the rate of detecting antibodies against both parasites was higher using the IFA test than using the CF test. The IFA method was more effective for diagnosis of Babesia infection than the CF technique. 相似文献
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Indirect fluorescent antibody titers to Dirofilaria immitis microfilaria (IFA-mf) and peripheral eosinophilia were recorded from 15 to 52 months in ten experimentally infected dogs with occult dirofilariasis (heartworm infection without microfilaremia). Five dogs which were experimentally sensitized with D immitis microfilaria did not exhibit microfilaremia after inoculation with infective-stage larvae. In three other dogs, microfilaremia suddenly ceased after 4 to 7 months. In these three dogs, antimicrofilarial antibodies were detectable by IFA-mf test as soon as microfilaremia ended. In the remaining two dogs, which exhibited spontaneous occult dirofilariasis, antibodies were detected at the end of the prepatent period of 6 months. The presence of adult worms was confirmed by angiocardiography. Significant IFA=mf titers (greater than or equal to 1:8) persisted after successful treatment with an adulticide. Reinfection of treated dogs reestablished occult dirofilarasis. Eosinophilia was present in all dogs and peaked at about 3, 6, and 9 months after they were inoculated with infective-stage larvae. At necropsy, the ten dogs harbored gravid, reproducing adult worms in the heart and pulmonary arteries. 相似文献
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Stunting syndrome is an enteric disease of young turkeys that results in reduced growth (stunting) of poults and impaired feed efficiency. A virus, which has been termed the stunting syndrome agent (SSA), causes stunting syndrome. In this study passive immunity was evaluated as a method of protecting poults from stunting syndrome. One-day-old poults were injected with either tryptose phosphate broth, an anti-SSA antibody preparation, or an anti-Newcastle disease virus antibody preparation before challenge by placing them into SSA-contaminated isolators or control (nonchallenge) isolators. Poults that received anti-SSA antibodies were significantly heavier (P < 0.05) and did not display as severe clinical disease compared to birds that did not receive the anti-SSA antibodies. However, the birds that received anti-SSA antibodies and were challenged were significantly lighter (P < 0.05) than birds that were not challenged. The results of this trial demonstrate that the injection of anti-SSA antibodies benefited poults undergoing stunting syndrome. The role of passive immunity, either through breeder hen vaccination or through supplying antibodies to poults artificially (i.e., at the hatchery), may have future applications in alleviating stunting syndrome. 相似文献
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Yahara Y Ohkubo Y Kariwa H Takashima I 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(7):583-588
To evaluate the immunofluorescent antibody (IFA) test and enzyme-linked immunosorbent assay (ELISA) for detecting the porcine reproductive and respiratory syndrome virus (PRRSV) antibody, conventional pigs in PRRSV-positive and -negative commercial farms were examined. Antibody development patterns in ELISA and IFA tests were compared in 3 week old piglets experimentally infected with the PRRSV. The virus was detected from 2 days post infection (PI) and then the antibody titers and S/P ratios rose by both methods. A total of 208 serum samples were collected from 4 PRRSV-negative farms and 210 samples from PRRSV-positive farms, and were tested for the PRRSV antibody by IFA and ELISA. The titer of 64 should be set as the cut-off point in IFA for field sera. Similarly, the cut-off S/P ratio should be set at 0.4 in ELISA. A high degree of correlation was observed between antibody titers by the two methods in these 418 samples, with a correlation coefficient of 0.84. The coincidence rate between the two tests was 84.7% (354/418). In non-coincident cases, ELISA was able to detect the antibody with a low titer in the serum samples which were negative in IFA but from PRRSV positive farms. ELISA was more sensitive than IFA to detect PRRSV infected animals or farms. 相似文献
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Results of complement-fixation (CF), indirect fluorescent antibody (IFA), and card agglutination (CT) tests were statistically compared, using 380 serum samples obtained from 140 cattle which were disease-free or naturally or experimentally infected with Anaplasma marginale of Colombian origin. The IFA test was significantly the most sensitive for detection of amimals infected with anaplasmosis (97%); the CT test and the CF test were less so (84% and 79%, respectively). However, the most efficient test for identifying noninfected animals was the CF test (100%), and the CT and the IFA tests were less efficient (98% and 90%). A linear regression analysis performed on the average IFA and CF titers of 10 calves artificially infected with A marginale during a 20-week period showed significant regression coefficients for both tests. The regression line for the CF titers decreased below the sensitivity threshold at 14 weeks after calves were inoculated, whereas the regression line for the IFA titers continued above the sensitivity threshold 20 weeks after inoculation. The CT test also detected antibodies until the end of the observation period. 相似文献
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The kinetics of antibody production response to experimentally induced infection of dogs with Ehrlichia canis was determined by ion-exchange and molecularsieve chromatography and by indirect fluorescent antibody (IFA) test. The first IFA antibody at 7 days after inoculation resided in immunoglobulin M (IgM) and immunoglobulin A (IgA) classes. At approximately 21 days after inoculation, the antibody was in IgM, IgA, and immunoglobulin G (IgG) classes. Thereafter, antibody concentrations continued to increase in the IgG class; those in the other 2 immunoglobulin classes had a variable pattern. In 2 dogs which died 60 and 114 days after inoculation, a decrease of antibody concentration in the 3 immunoglobulin classes was evident at the time of death. In the carrier dog, however, which was killed 147 days after inoculation, antibody concentrations sustained increasing titers in the 3 immunoglobulin classes. 相似文献
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The effect of malabsorption syndrome (stunting or runting syndrome) on the thyroid function of broilers was investigated in control and inoculated broilers from 1 to 29 days of age. The broilers were infected at 1 day of age with intestinal homogenates from chickens naturally suffering from this syndrome. The body weight of inoculated broilers was significantly (P less than 0.05) lower 1 week after inoculation than that of controls. The level of thyroxine in the serum of inoculated birds was lower (P less than 0.05) from day 6 through the remainder of the trial. The level of triiodothyronine of inoculated birds was depressed (P less than 0.05) on day 4, but 1 week later it returned to normal. The earliest phenomenon indicative of disturbance of thyroid function was the significant depression of 5'-deiodination in liver homogenates of inoculated broilers as early as day 2. It is concluded that thyroid function is one of the earliest targets of this syndrome. 相似文献
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Genetic, antigenic, and pathogenic variability is known to exist among porcine reproductive and respiratory syndrome (PRRS) viruses and has garnered great attention for diagnostics and disease control/prevention. A comparative serologic study was conducted on five field and two cell-attenuated viruses to determine if serologic responses to PRRS virus infection could be influenced by biotypic and/or genotypic differences of the viruses. The isolates used for the study varied in their virulence to pigs and in genomic sequences. Ten pigs were inoculated with each isolate (1x10(3) TCID(50)) via the intranasal route. All inoculated animals became viremic during the study period. Some animals inoculated with the attenuated viruses remained seronegative until the end of the study (42 days post-inoculation (PI)), but all of the animals inoculated with field viruses developed enzyme-linked immunosorbent assay (ELISA)- and indirect fluorescent antibody (IFA)-detectable antibodies, regardless of the virus strain used in the IFA assay. In contrast, a great degree of variation in the onset and level of serum-virus neutralization (SVN) antibody was observed by individual pigs and by each virus. The reactivity of SVN antibody was highly specific for homologous viruses. Cross-neutralization titers were better correlated with sequence homology of open-reading frames (ORFs) 4 and 5 among the viruses than any other structural genes. We conclude that the biotypic difference among PRRS viruses may affect the kinetic of humoral immune response in infected pigs. The IFA test may be used as a confirmatory test when a false-positive ELISA result is suspected or vise-a-versa, but SVN antibody titers are highly affected by antigenic variability. 相似文献
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W Lu F A Osorio M B Rhodes R A Moxley 《Journal of veterinary diagnostic investigation》1991,3(2):119-123
Two enzyme immunoassays (EIA) were developed for the detection of swine transmissible gastroenteritis virus (TGEV) antigens. The 2 EIAs used the same detecting system, a monoclonal antibody conjugated to horseradish peroxidase, but used different capture systems including a monoclonal antibody (m-EIA) or a polyclonal antibody (p-EIA). The EIAs were compared with the fluorescent antibody test (FAT) and electron microscopy (EM) for the detection of TGEV in intestinal samples of experimentally inoculated gnotobiotic piglets and of conventional diarrheic pigs submitted for diagnosis. In the gnotobiotic piglets experimentally inoculated with TGEV, 81.8% (9/11) were positive for TGEV by p-EIA, and 72.7% (8/11) were positive by m-EIA. In comparison, 81.8% (9/11) were positive by FAT and 27.2% (3/11) were positive by EM. Three noninfected controls were negative by all tests. In the diagnostic samples, 86.0% (43/50) were positive by p-EIA, 68.2% (30/44) were positive by m-EIA, 28.6% (14/49) were positive by IFA, and 38.0% (19/50) were positive by EM. The m-EIA had a higher agreement with FAT and EM than did p-EIA. 相似文献
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S L Seefeldt C A Kirkbride J P Dubey 《Journal of veterinary diagnostic investigation》1989,1(2):124-127
Results obtained in an enzyme-linked immunosorbent assay (ELISA), an indirect fluorescent antibody test (IFA), and a modified direct agglutination test (MAT) for Toxoplasma gondii antibodies from examination of fetal fluids from 377 aborted ovine fetuses were compared. Sixty-seven samples were positive by MAT (titers 1:16 to greater than 1:65,536), 58 were positive by ELISA, and 62 were positive by immunoglobulin G-IFA. The MAT was preferred because it required less time, labor, and special equipment. It was simple to run, could be done on serum from any species without modification, and it was more effective than the IFA for detecting toxoplasma antibodies in severely autolyzed fetuses. No advantage was found in determining immunoglobulin M antibodies in ovine fetal sera. 相似文献
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Eastern Screech Owls (EASOs) were experimentally infected with the pathogenic New York 1999 strain of West Nile virus (WNV) by subcutaneous injection or per os. Two of nine subcutaneously inoculated birds died or were euthanatized on 8 or 9 days postinfection (DPI) after <24 hr of lethargy and recumbency. All subcutaneously inoculated birds developed levels of viremia that are likely infectious to mosquitoes, with peak viremia levels ranging from 10(5.0) to 10(9.6) plaque-forming units/ml. Despite the viremia, the remaining seven birds did not display signs of illness. All birds alive beyond 5 DPI seroconverted, although the morbid birds demonstrated significantly lower antibody titers than the clinically normal birds. Cagemates of infected birds did not become infected. One of five orally exposed EASOs became viremic and seroconverted, whereas WNV infection in the remaining four birds was not evident. All infected birds shed virus via the oral and cloacal route. Early during infection, WNV targeted skin, spleen, esophagus, and skeletal muscle. The two morbid owls had myocardial and skeletal muscle necrosis and mild encephalitis and nephritis, whereas some of the clinically healthy birds that were sacrificed on 14 DPI had myocardial arteritis and renal phlebitis. WNV is a significant pathogen of EASOs, causing pathologic lesions with varying clinical outcomes. 相似文献
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The antibody response of six calves infected with 500 metacercariae of Fasciola gigantica each was monitored throughout 30 weeks of infection using an indirect fluorescent antibody technique (IFA). In vitro excysted F gigantica were employed as the test antigen. All animals showed high antibody titres from two to six weeks post-infection. Thereafter the antibody titres diminished gradually. Although all the experimentally infected animals harboured fluke burdens at autopsy, most gave negative IFA tests from 22 weeks post infection onwards. Specific immunofluorescent staining occurred on the surface glycocalyx of the newly excysted flukes. It is likely that this glycocalyx provides one of the earliest antigenic stimuli for the host's immune reactions to fascioliasis. 相似文献
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Paul S Wilkerson MJ Shuman W Harkin KR 《Veterinary immunology and immunopathology》2005,107(3-4):315-325
Anti-nuclear antibody (ANA) is one of the diagnostic parameters that support a diagnosis of autoimmune disorders in humans, dogs, and horses, particularly the condition systemic lupus erythematosus (SLE). The most commonly used method for detecting ANA in canine serum is the indirect immunofluorescence antibody assay (IFA) that detects dog IgG with reactivity towards mammalian cell nuclei. Interpretation of the IFA results is very subjective and dependent on the source of tissue/cellular substrate. We have developed a flow cytometry based assay to detect canine serum antibodies specific to histones. Histones were chosen as the target antigen because these nuclear proteins are the most common nuclear substrate for ANA in dogs with SLE. Microsphere beads were coated with histones and incubated with canine sera. Bound anti-histone antibodies were detected by FITC-conjugated rabbit F(ab')2 anti-dog IgG. Sera from four groups of dogs (47 dogs total) were tested for anti-histone antibodies and compared with the traditional IFA assay. The groups included 15 healthy dogs, 15 dogs with noninflammatory diseases, 9 dogs with polyarthritis and positive ANA, and 8 German shepherds with perianal fistulas. The microsphere assay results indicated that only one dog in the noninflammatory group and four out of nine dogs in the polyarthritis group had mean fluorescent intensity values above our established cut-off (defined as 2 S.D. above the mean of healthy controls). There was moderate agreement between the anti-histone assay and the traditional ANA (kappa statistic=0.54). Absorption of ANA positive serum with total histones dramatically diminished the fluorescent signal detected by flow cytometry and the speckled nuclear pattern observed by IFA, whereas preabsorption did not change the diffuse nuclear staining pattern. These findings indicate that the anti-histone assay will not replace the ANA test and that other nuclear proteins, such as ribonucleoproteins may contribute to the diffuse ANA patterns. 相似文献
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The DB2 calf strain of bovine coronavirus (BCV) was used to inoculate 1-day-old specific-pathogen-free (SPF) turkey poults in three trials. In all trials, the birds developed clinical signs of enteritis at 48-72 hr postinoculation. Birds euthanatized at 3, 5, and 7 days postinoculation (DPI) had flaccid, pale intestines with watery contents, and the ceca were markedly enlarged with frothy contents. Coronavirus particles were detected by immune electron microscopy with BCV antibodies from the intestinal contents of birds killed at 3, 5, 7, and 12 DPI. Body weights of inoculated poults killed at 3, 5, and 7 DPI were significantly reduced as compared with controls. Hemagglutinating antibodies were detected in sera of convalescent birds at 12 DPI. However, experimental inoculation of 1-day-old SPF chicks in two trials with the same virus resulted in no clinical signs or macroscopic or microscopic lesions. No coronaviruses were detected from intestinal contents, and there were no significant differences in body weights of inoculated and noninoculated control chicks. 相似文献
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Complement-fixation (CF) and indirect fluorescent antibody (IFA) antigens were prepared from Babesia bigemina isolates obtained in Texas. These serologic procedures were evaluated on 130 serum samples sequentially collected from 5 B bigemina-infected mature cattle, beginning on the day of exposure and continuing for 175 day thereafter. Both tests were effective in detecting specific antibodies for the first 84 days of infection, with 57 of 60 (95%) serums tested being positive on the CF test and 57 of 57 (100%) tests being positive to the IFA test. During the interval from 98 to 175 days, 24 of 60 (40%) of the serums tested were positive with the CF test, and 53 of 56 (95%) were positive with the IFA test. During the first 84 days, a similar linear regression occurred in both CF and IFA serum titers, but after 98 days the IFA regression flattened out, whereas the CF titers decreased below the sensitivity threshold in 60% of the serums tested. 相似文献
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In a 2 X 2 factorial study, a broiler starter ration was amended for vitamin A (control, C; deficient, A) and probiotic status (-, P) to investigate their modulatory effects onthe host immune system. Birds were inoculated orally with Eimeria acervulina (EA) oocysts, and disease susceptibility was evaluated by assessment of fecal oocyst shedding. Humoral and local cellular mediated immunity were assessed by evaluation of antibody and cytokine (interferon-gamma [IFN-gamma] and interleukin-2 [IL-2]) levels in sera and intestinal secretions on a 3-day interval after inoculation. Fecal oocyst shedding was highest (P < 0.05) in A- birds, followed by AP, C-, and CP birds. Feeding the probiotic reduced shed oocysts by 20% in A fed birds and by 26% in C fed birds. Intestinal IFN-gamma was relatively constant in all treatment groups except for A-, where it declined steadily and was lower (P < 0.05) from day 6 on. Serum IFN-gamma levels fluctuated within each treatment and over time were not revealing. Intestinal IL-2 was highest in CP birds at 3 and 9 days postinfection (DPI) and lowest in A- birds at 3, 9, and 12 DPI (P < 0.05); no difference between treatments was found at 6 DPI (P > 0.05). Eimeria-specific intestinal antibody (Ab) level was constant (P > 0.05) in C- birds but increased with time (P < 0.05) in A-, AP, and CP birds. Serum Ab levels were also constant in A- and CP birds but increased (P < 0.05) in C- and AP birds after 6 DPI. The data demonstrate for the first time a probiotic-enhanced immunity in vitamin A deficient birds. This study is also the first to demonstrate the probiotic effect on local cell-mediated immunity of chickens, best manifested by apparent lower intestinal invasion and development by EA, on the basis of higher IL-2 secretion and lower EA oocyst production. 相似文献
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In the fall of 1999, West Nile virus (WNV) was isolated for the first time in the Western Hemisphere during an outbreak of neurologic disease in humans, horses, and wild and zoo birds in the northeastern United States. Chickens are a potential reservoir for WNV, and little is known about the pathogenicity of WNV in domestic chickens. Seven-week-old chickens derived from a specific-pathogen-free flock were inoculated subcutaneously with 1.8 x 10(3) 50% tissue culture infectious dose of a crow isolate of WNV in order to observe clinical signs and evaluate the viremic phase, gross and microscopic lesions, contact transmission, and immunologic response. There were no observable clinical signs in the WNV-inoculated chickens during the 21-day observation period. However, histopathologic examination of tissues revealed myocardial necrosis, nephritis, and pneumonitis at 5 and 10 days postinoculation (DPI); moderate to severe nonsuppurative encephalitis also was observed in brain tissue from one of four inoculated birds examined at 21 DPI. WNV was recovered from blood plasma for up to 8 DPI. Virus titers as high as 10(5)/ml in plasma were observed at 4 DPI. Fecal shedding of virus was detected in cloacal swabs on 4 and 5 DPI only. The WNV also was isolated from myocardium, spleen, kidney, lung, and intestine collected from chickens euthanatized at 3, 5, and 10 DPI. No virus was isolated from inoculated chickens after 10 DPI. Antibodies specific to WNV were detected in inoculated chickens as early as 5 DPI by the plaque reduction neutralization test and 7 DPI by the indirect fluorescent antibody test. Chickens placed in contact with inoculated chickens at 1 DPI lacked WNV-specific antibodies, and no WNV was isolated from their blood plasma or cloacal swabs throughout the 21 days of the experiment. 相似文献