scholarly journals Evaluation of an Indirect Enzyme-Linked Immunosorbent Assay for Routine Screening of Theiler's Murine Encephalomyelitis Virus Antibodies in Mice Colonies

2008 ◽  
Vol 20 (6) ◽  
pp. 789-791 ◽  
Author(s):  
Juan M. Laborde ◽  
Cecilia Carbone ◽  
Santiago G. Corva ◽  
Cecilia M. Galosi

The current study demonstrates the ability of an indirect enzyme-linked immunosorbent assay (iELISA) to detect antibodies against Theiler's murine encephalomyelitis virus in mice colonies. The antigen was produced from infected baby hamster kidney (BHK)-21 cells and treated with 1% Nonidet P40 in saline buffer. Control antigen was prepared following the same procedure using uninfected BHK-21 cells. The optimal antigen and serum dilutions were established. The reaction was revealed using an anti-mouse-horseradish peroxidase conjugate and 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid). Optimized iELISA was validated by detection of antibodies in known positive and negative serum samples before testing the samples of unknown status. Performance of the iELISA was compared with the indirect fluorescent antibody test, and the cutoff value was determined by receiver operating curve. Indirect ELISA showed 100% sensitivity, 99.38% specificity, and 97.78% predictive positive value. The antigen used is easy to produce, and no special equipment is required. The iELISA developed is simple and provides a rapid and less costly tool for diagnosis and research.

1989 ◽  
Vol 1 (2) ◽  
pp. 124-127 ◽  
Author(s):  
Sheryl L. Seefeldt ◽  
Clyde A. Kirkbride ◽  
Jitender P. Dubey

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.


1999 ◽  
Vol 37 (11) ◽  
pp. 3540-3544 ◽  
Author(s):  
Jacob W. Ijdo ◽  
Caiyun Wu ◽  
Louis A. Magnarelli ◽  
Erol Fikrig

Current antibody testing for human granulocytic ehrlichiosis relies predominantly on indirect fluorescent-antibody assays and immunoblot analysis. Shortcomings of these techniques include high cost and variability of test results associated with the use of different strains of antigens derived from either horses or cultured HL-60 cells. We used recombinant protein HGE-44, expressed and purified as a maltose-binding protein (MBP) fusion peptide, as an antigen in a polyvalent enzyme-linked immunosorbent assay (ELISA). Fifty-five normal serum samples from healthy humans served as a reference to establish cutoff levels. Thirty-three of 38 HGE patient serum samples (87%), previously confirmed by positive whole-cell immunoblotting, reacted positively in the recombinant ELISA. In specificity analyses, serum samples from patients with Lyme disease, syphilis, rheumatoid arthritis, and human monocytic ehrlichiosis (HME) did not react with HGE-44–MBP antigen, except for one sample (specificity, 98%). We conclude that recombinant HGE-44 antigen is a suitable antigen in an ELISA for the laboratory diagnosis and epidemiological study of HGE.


2011 ◽  
Vol 59 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Gorazd Vengušt ◽  
Peter Hostnik ◽  
Mojca Cerovšek ◽  
Polona Cilenšek ◽  
Tadej Malovrh

Serum samples of 746 shot wild boars collected throughout Slovenia during the hunting season of 2005/2006 were examined for the presence of antibodies against rabies virus: 541 samples were collected in areas subjected to yearly antirabies vaccination, and 205 samples were collected in areas where preventive antirabies vaccination was not practised. Using a modified enzyme-linked immunosorbent assay (ELISA), in 209 out of 746 sera (28%) the levels of antibodies against rabies virus were higher than 0.5 IU/ml and deemed positive. A total of 173/541 (32%) and 36/205 (18%) samples were positive in the vaccinated and nonvaccinated areas, respectively. Further analysis of 191 out of the 746 samples using the fluorescent antibody virus neutralisation (FAVN) test revealed the presence of antibodies against rabies virus in 122/191 (64%) samples. This is the first extended research reporting that antibodies against rabies virus that originate from preventive oral vaccination targeting the fox population are present in wild boar.


2004 ◽  
Vol 11 (3) ◽  
pp. 503-514 ◽  
Author(s):  
Neal H. Ferrin ◽  
Ying Fang ◽  
Craig R. Johnson ◽  
Michael P. Murtaugh ◽  
Dale D. Polson ◽  
...  

ABSTRACT Porcine reproductive and respiratory syndrome (PRRS) continues to be one of the most significant diseases of swine. IDEXX HerdChek PRRS, a commercially available enzyme-linked immunosorbent assay (ELISA), has become the industry standard for the detection of antibodies against PRRS virus (PRRSV). The need to accurately determine the PRRSV serostatus of herds and individual animals has prompted the development of several follow-up assay methods. A highly specific and repeatable blocking ELISA (bELISA) was developed on the basis of the use of an expressed PRRSV nucleocapsid (N) protein as the antigen and a biotinylated monoclonal antibody. Validation of the bELISA used sera from 316 animals experimentally and naturally infected with North American PRRSV and sera from 370 uninfected animals. Receiver operating characteristic analysis of the data calculated a diagnostic sensitivity of 97.8% and a diagnostic specificity of 100%. The between-run coefficient of variation of an internal quality control serum was 4.24%. The bELISA was able to detect seroconversion as well as the IDEXX ELISA and the indirect fluorescent antibody (IFA) assay; kappa values were 0.94 and 0.96, respectively. A collection of 133 serum samples with unexpected positive IDEXX ELISA results was obtained from 4,038 diagnostic samples submitted from farms from which PRRS-negative results were expected. The bELISA identified 97% of the samples as PRRS seronegative, while the IFA identified 100% as seronegative. The anticipated use of the bELISA is as a follow-up test to the IDEXX ELISA for determining the PRRSV serostatus of individual animals with unexpected positive test results from swine herds from which negative results are expected.


2019 ◽  
Vol 65 (5) ◽  
pp. 343-352
Author(s):  
Ying Shan ◽  
Yajie Liu ◽  
Ziqi Liu ◽  
Guowei Li ◽  
Cong Chen ◽  
...  

Porcine epidemic diarrhea virus (PEDV) causes severe infectious diseases in all ages of swine and leads to serious economic losses. Serologic tests are widely accepted and used to detect anti-PEDV antibodies that could indicate PEDV infection or vaccination. In this study, PEDV recombinant S1 protein (rS1) was expressed with the Bac-to-Bac system and purified by nickel-affinity chromatography. An indirect enzyme-linked immunosorbent assay based on rS1 (rS1-ELISA) was then developed and optimized by checkerboard assays with serial dilutions of antigen and serum. Serum samples from 453 domestic pigs and 42 vaccinated pigs were analyzed by the indirect fluorescent antibody (IFA) test and rS1-ELISA. Taking IFA as a gold standard, rS1-ELISA produced a high sensitivity (90.7%) and specificity (94.6%) by a receiver operating characteristic (ROC) curve. In addition, ROC analysis also revealed that rS1-ELISA was consistent with IFA (area under the curve 0.9583 ± 0.0082). This rS1-ELISA was then applied to antibody detection in inactivated PEDV vaccinated pigs. The antibody could be detected 2–4 weeks after the first inoculation. These results indicated that the rS1-ELISA established in this study provides a promising and reliable tool for serologic detection of anti-PEDV IgG antibodies in infected or vaccinated pigs.


2009 ◽  
Vol 29 (2) ◽  
pp. 120-124 ◽  
Author(s):  
Débora Carvalho ◽  
Trícia M.F.S. Oliveira ◽  
Cristiane D. Baldani ◽  
Rosangela Z. Machado

Visceral leishmaniasis is an emergent zoonosis with an increasing number of new cases in Brazil where the domestic dog is an important parasite reservoir in the infectious cycle of Leishmania chagasi. An enzyme-linked immunosorbent assay (ELISA), based upon the use of a total soluble antigenic preparation of L. chagasi, was adapted for the detection of IgM antibodies in the serum of infected dogs. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkboard titrations. The specificity and sensitivity of the ELISA were 100 %. A total of 110 serum samples were taken from dogs in Belo Horizonte, Minas Gerais, Brazil, and examined for anti-L. chagasi IgM antibody by ELISA and indirect fluorescent antibody test (IFAT). About 25% (n=27) of all the dogs tested were found serologically positive for L. chagasi by IFAT, while 89.09% (n=98) were seropositive by ELISA. The results obtained by ELISA and IFAT were significantly different (P<0.01). The combined use of ELISA and IFAT is recommended in order to enable veterinary services to more efficiently detect canine visceral leishmaniasis.


2000 ◽  
Vol 38 (4) ◽  
pp. 1645-1647 ◽  
Author(s):  
Peter R. Field ◽  
Jody L. Mitchell ◽  
Avelina Santiago ◽  
David J. Dickeson ◽  
Sau-Wan Chan ◽  
...  

A commercially available enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Q fever (PanBio Coxiella burnetiiimmunoglobulin M [IgM] ELISA, QFM-200) was compared to the indirect fluorescent antibody test (IFAT) for C. burnetii IgM and the complement fixation test (CFT). The ELISA demonstrated 92% agreement with the reference method (IFAT), and gave a sensitivity of 99% (69 of 70 samples) and a specificity of 88% (106 of 121). Specificity can be increased with confirmation by IFAT. CFT was found to have a specificity of 90% (107 of 119), although it was lacking in sensitivity (73%; 51 of 70). No cross-reactivity was observed in the ELISA with serum samples from patients with mycoplasma (n = 6), chlamydia (n = 5), or legionella (n = 4) infections, although 2 of 5 patients with leptospirosis and 1 of 4 samples containing rheumatoid factor (RF) demonstrated positive results in the ELISA. Results indicate that the performance of the PanBio C. burnetii (Q fever) IgM ELISA (F = 187) is superior to that of CFT (F = 163), and consequently the ELISA should be a useful aid in the diagnosis of acute Q fever.


2008 ◽  
Vol 17 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Trícia Maria F. de Sousa Oliveira ◽  
Patrícia I. Furuta ◽  
Débora de Carvalho ◽  
Rosangela Z. Machado

To verify the presence of cross-reaction among leishmaniosis, ehrlichiosis and babesiosis in serological diagnostics used in human visceral leishmaniasis control programs, serum samples from leishmaniasis endemic and non-endemic areas were collected and tested by Indirect Fluorescent Antibody (IFAT) and Enzyme-linked immunosorbent assay (ELISA). All serum samples from endemic areas were positive for Leishmania sp., by ELISA and IFAT, 51% positive for Babesia canis and 43% for Ehrlichia canis by IFAT. None of the serum samples from non-endemic areas were positive for Leishmania sp., by IFAT, but 67% were positive for B. canis and 78% for E. canis using the same test. When tested by ELISA for Leishmania sp., four samples from non-endemic area were positive. These dogs were then located and no clinical signs, parasites or antibody was detected in new tests for a six month period. Only one of these 4 samples was positive for B. canis by IFAT and ELISA and three for E. canis by IFAT. The results of the work suggest a co-infection in the endemic area and no serological cross-reaction among these parasites by IFAT and ELISA.


mSphere ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Juan Carlos Mora-Díaz ◽  
Ronaldo Magtoto ◽  
Elizabeth Houston ◽  
David Baum ◽  
José Antonio Carrillo-Ávila ◽  
...  

ABSTRACT Members of family Coronaviridae cause a variety of diseases in birds and mammals. Porcine hemagglutinating encephalomyelitis virus (PHEV), a lesser-researched coronavirus, can infect naive pigs of any age, but clinical disease is observed in pigs ≤4 weeks of age. No commercial PHEV vaccines are available, and neonatal protection from PHEV-associated disease is presumably dependent on lactogenic immunity. Although subclinical PHEV infections are thought to be common, PHEV ecology in commercial swine herds is unknown. To begin to address this gap in knowledge, a serum IgG antibody enzyme-linked immunosorbent assay (ELISA) based on the S1 protein was developed and evaluated on known-status samples and then used to estimate PHEV seroprevalence in U.S. sow herds. Assessment of the diagnostic performance of the PHEV S1 ELISA using serum samples (n = 924) collected from 7-week-old pigs (n = 84; 12 pigs per group) inoculated with PHEV, porcine epidemic diarrhea virus, transmissible gastroenteritis virus, porcine respiratory coronavirus, or porcine deltacoronavirus showed that a sample-to-positive cutoff value of ≥0.6 was both sensitive and specific, i.e., all PHEV-inoculated pigs were seropositive from days postinoculation 10 to 42, and no cross-reactivity was observed in samples from other groups. The PHEV S1 ELISA was then used to estimate PHEV seroprevalence in U.S. sow herds (19 states) using 2,756 serum samples from breeding females (>28 weeks old) on commercial farms (n = 104) with no history of PHEV-associated disease. The overall seroprevalence was 53.35% (confidence interval [CI], ±1.86%) and herd seroprevalence was 96.15% (CI, ±3.70%). IMPORTANCE There is a paucity of information concerning the ecology of porcine hemagglutinating encephalomyelitis virus (PHEV) in commercial swine herds. This study provided evidence that PHEV infection is endemic and highly prevalent in U.S. swine herds. These results raised questions for future studies regarding the impact of endemic PHEV on swine health and the mechanisms by which this virus circulates in endemically infected populations. Regardless, the availability of the validated PHEV S1 enzyme-linked immunosorbent assay (ELISA) provides the means for swine producers to detect and monitor PHEV infections, confirm prior exposure to the virus, and to evaluate the immune status of breeding herds.


2012 ◽  
Vol 57 (No. 3) ◽  
pp. 111-114 ◽  
Author(s):  
E. Bartova ◽  
K. Sedlak

Toxoplasma gondii is zoonotic protozoan parasite that causes infections in many vertebrate species. The present study determined the seroprevalence of T. gondii and N. caninum in goats from the Czech Republic. Serum samples were collected from 251 healthy adult goats in the Czech Republic during the years 2006 to 2009. Sera samples were tested for serum antibodies to Toxoplasma gondii by an enzyme-linked immunosorbent assay with cut off equal to or higher than 50% S/P. The same samples were tested for serum antibodies to Neospora caninum by a competitive-inhibition enzyme-linked immunosorbent assay with cut off equal to or higher than 30% inhibition; positive sera were confirmed by an indirect fluorescent antibody test with cut-off titre equal to or higher than 40. Sera positive in both tests were marked as positive. In total, 166 (66%) and 15 (6%) goat sera reacted positively for T. gondii and N. caninum antibodies, respectively. All sera positive for N. caninum antibodies were simultaneously positive for T. gondii antibodies. This is the&nbsp;first detection of N.&nbsp;caninum antibodies in goats in the Czech Republic. Our findings indicate that goats in the Czech Republic are frequently exposed to T.&nbsp;gondii, but less frequently to N. caninum. &nbsp;


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