scholarly journals Comparison of Immunohistochemistry, Electron Microscopy, and Direct Fluorescent Antibody Test for the Detection of Bovine Coronavirus

1998 ◽  
Vol 10 (2) ◽  
pp. 152-157 ◽  
Author(s):  
Arshud M. Dar ◽  
Sanjay Kapil ◽  
Sagar M. Goyal
Keyword(s):  
Electron Microscopy ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Ease Of Use ◽  
Enzyme Linked Immunosorbent Assay ◽  
Moderate Degree ◽  
Bovine Coronavirus ◽  
Adult Cattle ◽  
Suitable Alternative ◽  
Direct Fluorescent Antibody

Bovine coronavirus (BCV) is 1 of the major causes of calf diarrhea and has also been implicated in respiratory infections of young calves and winter dysentery of adult cattle. Currently, transmission electron microscopy (TEM), direct fluorescent antibody (DFA), and enzyme-linked immunosorbent assay (ELISA) techniques are considered standard methods for the diagnosis of BCV infection. However, these techniques are not useful if fresh tissues and intestinal contents are not available for examination. The detection of viral antigens in formalin-fixed, paraffin-embedded tissues using immunohistochemistry (IHC) is a suitable alternative. In the present study, 166 tissue specimens were tested by IHC for the presence of BCV. These tissues were from animals whose feces were positive for rotavirus and/or coronavirus by TEM. Some of these samples were also tested by DFA. Thus, TEM, DFA, and IHC were compared for the detection of BCV. There was 56% agreement among the 3 methods (overall kappa = 0.368). When IHC was compared with TEM, 78% agreement was observed (kappa = 0.475). Similarly, IHC and DFA had 64% agreement (kappa = 0.277). These kappa values indicate a moderate degree of agreement between IHC and TEM; agreement between IHC and DFA was fair. The results of this study indicate that IHC may be a suitable adjunct for the detection of BCV because of its simplicity, ease of use, and relatively close correlation with TEM results.

scholarly journals Head-to-Head Evaluation of Five Chlamydia Tests Relative to a Quality-Assured Culture Standard

1999 ◽  
Vol 37 (3) ◽  
pp. 681-685 ◽  
Author(s):  
Wilbert J. Newhall ◽  
Robert E. Johnson ◽  
Susan DeLisle ◽  
David Fine ◽  
Alula Hadgu ◽  
...  
Keyword(s):  
Lower Cost ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Ease Of Use ◽  
Nucleic Acid Amplification ◽  
Competition Assay ◽  
Blocking Antibody ◽  
Direct Fluorescent Antibody ◽  
Confirmatory Tests ◽  
Positive Results

Nucleic acid amplification tests offer superior sensitivity for the detection of Chlamydia trachomatis infection, but many laboratories still use nonamplification methods because of the lower cost and ease of use. In spite of their availability for more than a decade, few studies have directly compared the nonamplification tests. Such comparisons are still needed in addition to studies that directly compare individual nonamplification and amplification tests. The purpose of this study was to evaluate and compare the performance characteristics relative to culture of five different tests for the detection of C. trachomatis with and without confirmation of positive results. The tests were applied to endocervical specimens from 4,980 women attending family planning clinics in the northwestern United States. The five nonculture tests included Chlamydiazyme (Abbott), MicroTrak direct fluorescent antibody (DFA) (Syva), MicroTrak enzyme immunoassay (EIA) (Syva), Pace 2 (Gen-Probe), and Pathfinder EIA (Sanofi/Kallestad). All positive results obtained with a nonculture test (except MicroTrak DFA) were confirmed by testing the original specimens with a blocking antibody test (Chlamydiazyme), a cytospin DFA (MicroTrak EIA and Pathfinder EIA), and a probe competition assay (Pace 2). The prevalence of culture-proven chlamydia was 3.9%. The sensitivities of the nonculture tests were in a range from 62 to 75%, and significant differences between tests in terms of sensitivity were observed. The positive predictive value for each test was 0.85 or higher. The specificities of the nonculture tests without performance of confirmations were greater than 99%. Performing confirmatory tests eliminated nearly all of the false positives.

scholarly journals The Search forIxodes damminiandBorrelia burgdorferiin Nova Scotia

1992 ◽  
Vol 3 (5) ◽  
pp. 224-230 ◽  
Author(s):  
Colin R Bell ◽  
Harold B Specht ◽  
B Ann Coombs
Keyword(s):  
Nova Scotia ◽  
Indirect Fluorescent Antibody Test ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Dermacentor Variabilis ◽  
Small Sample ◽  
Enzyme Linked Immunosorbent Assay ◽  
Indirect Fluorescent Antibody ◽  
Migrating Birds ◽  
Sera Samples

Twenty-fourIxodes damminiticks (23 adults and one nymph) have been recovered in Nova Scotia since 1984. There has not been a systematic search for larvae and none has been identified. The recovery of the nymph from a road-killed yellow throat bird,Geothypis trichas,in late May 1990 supports the contention that migrating birds are bringing deer ticks into the province every spring. In March and April 1991, four adult deer ticks were identified, suggesting that these ticks had overwintered. These deer tick specimens indicate that it is possible thatI damminiis becoming established in Nova Scotia, if it is not already established. There has been no evidence for the existence ofBorrelia burgdorferiin the province. The spirochete was not cultured from 650Dermacentor variabilisticks, nor were antibodies detected in a small sample of feral rodents using an indirect fluorescent antibody test. A survey of 137 dog sera samples, analyzed by enzyme-linked immunosorbent assay, also proved negative. There has been no confirmed indigenous case of Lyme disease in Nova Scotia to date.

scholarly journals Comparison of Enzyme-Linked Immunosorbent Assay, Indirect Fluorescent Antibody Test, and Direct Agglutination Test for Detecting Toxoplasma Gondii Antibodies in Naturally Aborted Ovine Fetuses

1989 ◽  
Vol 1 (2) ◽  
pp. 124-127 ◽  
Author(s):  
Sheryl L. Seefeldt ◽  
Clyde A. Kirkbride ◽  
Jitender P. Dubey
Keyword(s):  
Toxoplasma Gondii ◽  
Immunosorbent Assay ◽  
Indirect Fluorescent Antibody Test ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Agglutination Test ◽  
Indirect Fluorescent Antibody ◽  
Special Equipment

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 > 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.

scholarly journals A Comparative Analysis of Polymerase Chain Reaction and Direct Fluorescent Antibody Test for Diagnosis of Genital Herpes

2017 ◽  
Vol 9 (01) ◽  
pp. 053-056 ◽  
Author(s):  
Vrushali Patwardhan ◽  
Preena Bhalla ◽  
Deepti Rawat ◽  
Vijay Kumar Garg ◽  
Kabir Sardana ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Genital Herpes ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Conventional Polymerase Chain Reaction ◽  
Genital Ulcer ◽  
Chain Reaction ◽  
Direct Fluorescent Antibody ◽  
Polymerase Chain ◽  
Simplex Virus

ABSTRACT Objective: To compare laboratory tests that can simultaneously detect and type herpes simplex virus (HSV) directly from the genital ulcer specimens in clinically suspected cases of genital herpes. Materials and Methods: A study was conducted over 10 months and 44 adult male and female patients clinically suspected with genital herpes were recruited. Genital ulcer swab specimens were subjected to glycoprotein-G gene-based conventional polymerase chain reaction (PCR) and commercially available direct fluorescent antibody (DFA) test and the results were compared. Results: PCR for HSV was positive in 82% (36/44) cases. DFA was positive in 68.2% (30/44) cases. There was 100% agreement between HSV types detected by DFA and PCR. The strength of agreement between the results was better in primary genital herpes than recurrent cases. Conclusion: PCR was found to be better in the detection of HSV in recurrent genital herpes patients. It is a better modality, especially when genital herpes clinically presents with ulcerative or crusted lesions, and is also a cheaper alternative as compared to DFA.

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