scholarly journals A Peptide-Based Enzyme-Linked Immunosorbent Assay for Detecting Antibodies Against Avian Infectious Bronchitis Virus

2021 ◽  
Vol 7 ◽  
Author(s):  
Liping Yin ◽  
Qi Wu ◽  
Zhixian Lin ◽  
Kun Qian ◽  
Hongxia Shao ◽  
...  

Infectious bronchitis virus (IBV) causes substantial loss to the poultry industry despite extensive vaccination. Assessing the antibody response is important for the development and evaluation of effective vaccines. We have developed an enzyme-linked immunosorbent assay (ELISA) for the detection of IBV-specific antibodies, using a synthetic peptide based on a conserved sequence in the IBV spike protein. This peptide-based ELISA (pELISA) specifically detects antibodies to different genotypes of IBV but not antibodies against other common chicken viruses. This assay could detect IBV-specific antibody response on as early as day 7 postinfection. In the testing with field serum samples collected from chickens administered with IBV vaccines, the sensitivity, specificity, and accuracy of pELISA were 98.30, 94.12, and 98.8%, respectively, relative to indirect immunofluorescence assay. Our data demonstrate that the pELISA is of value for the detection of IBV antibody and the evaluation of IBV vaccines.

1996 ◽  
Vol 40 (3) ◽  
pp. 637-641 ◽  
Author(s):  
J D Cleary ◽  
S W Chapman ◽  
J Deng ◽  
C J Lobb

Our purpose was to develop and characterize an enzyme-linked immunosorbent assay (ELISA) which could measure the concentration of amphotericin B in serum. Amphotericin B was assayed by competition ELISA. Multiwell ELISA plates coated with amphotericin B (1.0 micrograms/ml) conjugated to bovine serum albumin were used to test replicates of serum samples spiked with amphotericin B. Purified rabbit polyclonal antibody against amphotericin B (1.4 micrograms/ml) was added subsequent to the instillation of samples spiked with unknown amounts of amphotericin B. Experiments were performed to test the sensitivity, specificity, precision, and accuracy of the assay. The ability to measure lipid-associated amphotericin B was also evaluated in preliminary studies. Analysis of reference samples containing amphotericin B yielded a traditional sigmoidal curve. The limits of detection were 0.15 to 156 micrograms/ml. The sensitivity of the assay was affected by light and temperature exposure. Assay specificity was altered only by the presence of nystatin, a polyene antifungal agent similar to amphotericin B. Intrarun (coefficient of variation = 3.0%) and interrun (coefficient of variation = 12.8%) coefficients of variation were calculated and were comparable to those in similar assays. The assay's correlation coefficient (r = 0.907) demonstrated a statistically significant correlation between the optical density of the sample and the concentration of drug in the sample. The amphotericin B ELISA's ease, precision, and overall accuracy suggest that this assay could be used for assessments of serum amphotericin B concentrations. Multiple research questions concerning the role of serum amphotericin B concentrations in toxicity and efficacy have gone unanswered because of the labor-intensive nature of the assays which have been available to date. The ability to easily and rapidly measure 40 duplicate samples containing amphotericin B should also prove to be a distinct advantage for clinical research or reference laboratories in addressing these questions.


2000 ◽  
Vol 38 (11) ◽  
pp. 4160-4166 ◽  
Author(s):  
Fang Ting Liang ◽  
Richard H. Jacobson ◽  
Reinhard K. Straubinger ◽  
Amy Grooters ◽  
Mario T. Philipp

Sera collected from dogs experimentally infected withBorrelia burgdorferi by tick inoculation were analyzed for an antibody response to each of the six invariable regions (IRs; i.e., IR1 to IR6) of VlsE, the variable surface antigen of B. burgdorferi. Six synthetic peptides (C1 to C6), which reproduced the six IR sequences were used as peptide-based, enzyme-linked immunosorbent assay (ELISA) antigens. Two IRs, IR2 and IR6, were found to be immunodominant. Studies with serially collected serum samples from experimentally infected dogs revealed that the antibody response to IR6 appears earlier and is stronger than that to IR2. Thus, the IR6 sequence alone appeared to be sufficient for serodiagnosis. When C6 alone was used as antigen, the peptide-based ELISA was positive in 7 of 23 dogs (30%) as early as 3 weeks postinfection. All dogs (n = 33) became strongly positive 1 or 2 weeks later, and this response persisted for the entire study, which lasted for 69 weeks. Of 55 sera submitted by veterinarians from dogs suspected of having Lyme disease, 19 were also positive by the C6 ELISA, compared to 20 positives detected by immunoblot analysis using cultured B. burgdorferi lysates as antigen. The sensitivity of using C2 and C6 together for detecting specific antibody in both experimentally infected and clinically diagnosed dogs was not better than sensitivity with C6 alone, confirming that C6 suffices as a diagnostic probe. Moreover, the C6 ELISA yielded 100% specificity with serum samples collected from 70 healthy dogs, 14 dogs with infections other than B. burgdorferi, and 15 animals vaccinated with either outer surface protein A, whole-spirochete vaccines, or the common puppy-vaccines. Therefore, this C6 ELISA was both sensitive and specific for the serodiagnosis of canine Lyme disease and could be used with vaccinated dogs.


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