scholarly journals Comparative examination of the serological response to bluetongue virus in diseased ruminants by competitive and double recognition enzime-linked immunosorbent assays

2018 ◽  
Vol 69 (3) ◽  
pp. 1088
Author(s):  
A. GAVRILOVIĆ ◽  
P. GAVRILOVIĆ ◽  
S. RADOJIČIĆ ◽  
D. KRNJAIĆ

Bluetongue (BT) is a viral non-contagious disease of ruminants which is transmitted by insects of the genus Culicoides. In recent years, BT has been a serious threat to livestock and to the economies of European countries. In Serbia the disease appeared for the first time in 2001, and after a 12 year period of freedom, it broke out again in 2014. Considering the actuality of this infectious disease, especially the need for prompt and rapid diagnostics, the aim of this paper was to determine the possibility of detecting the serological response in sheep and cattle with manifested clinical signs of the disease using two different methods: double recognition enzyme-linked immunosorbent assay (sELISA) and competitive enzyme-linked immunosorbent assay (cELISA). A total of 105 blood serum samples of cattle and sheep, which had exhibited clinical signs of BT during 2014, were taken for examination from a serum bank. Out of 74 blood serum samples of sheep and 31 blood serum samples of cattle, 52 samples of sheep and 18 samples of cattle tested positive using sELISA, while 50 samples of sheep and 18 samples of cattle gave positive reactions with cELISA. The results confirm the high sensitivity of sELISA which detected 4% more seropositive sheep in comparison with cELISA. Using Cohen’s kappa statistical analysis, almost perfect agreement was determined between the results (k>0,81) obtained by cELISA and sELISA.

2022 ◽  
Vol 20 (6) ◽  
pp. 72-80
Author(s):  
L. N. Lukhverchyk ◽  
G. L. Alatortseva ◽  
L. N. Nesterenko ◽  
V. Y. Kabargina ◽  
V. V. Dotsenko ◽  
...  

Relevance. The introduction of Varicella vaccine prophylaxis explains the need to develop a methodology for monitoring the vaccination effectiveness and the intensity of population immunity. This problem can be solved using quantitative immunoassay methods. Aim. Development of an enzyme-linked immunosorbent assay for the concentration of class G immunoglobulins (AB) to Varicella zoster virus (VZV) determining and assessing its functional characteristics and diagnostic efficiency. Materials and methods. Recombinant antigen GE VZV. WHO International Standard for Antibodies to VZV W1044. Blood serum samples from healthy people and patients with Chickenpox and Herpes zoster, blood serum samples containing IgG antibodies to herpes simplex viruses of the first and second types, cytomegalovirus, Epstein-Barr virus. Anti-VZV ELISA (IgG) reagent kit (Euroimmun, Germany). Indirect enzyme-linked immunosorbent assay. Immunization of animals with recombinant antigen GE, isolation, and purification of specific antibodies. Conjugation of monoclonal antibodies to human IgG with antibodies to antigen GE and with horseradish peroxidase. Results. An enzyme-linked immunosorbent assay in «an indirect» format has been developed to determine the specific antibodies to VZV concentration (IU/ml) in human serum/plasma. An artificial calibrator for determining the concentration of AB-VZV had been synthesized and standardized according to the International WHO-standard W1044. The main functional characteristics of the developed enzyme-linked immunosorbent assay are determined in accordance with GOST 51352-2013. The diagnostic kit was tested on blood serum samples from children with chickenpox (n = 43), adults with Herpes zoster (n = 158), healthy individuals (n = 781). The diagnostic sensitivity of the test system was 85%, the diagnostic specificity was 87% according to the ROC analysis. The absence of cross-reactivity of the test system was shown on samples with serological markers of other herpesvirus infections (n = 94). Comparative trials of the developed test system and its commercial analog, the Anti-VZV ELISA (IgG) reagent kit, did not reveal statistically significant differences between their functional characteristics. Conclusions. The developed test system for determining of the AB-VZV concentration in human serum/plasma in terms of its functional characteristics meets the GOST requirements, is characterized by high diagnostic efficiency, can be used to monitor the effectiveness of vaccine prophylaxis and strength of population immunity, as well as to assess the immune response in chickenpox and Herpes zoster.


2011 ◽  
Vol 80 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Eddy Listeš ◽  
Sanja Bosnić ◽  
Miroslav Benić ◽  
Josip Madić ◽  
Željko Cvetnić ◽  
...  

The aim of this study was to provide a description of the first epidemic of bluetongue and the first survey on midges of the genus Culicoides in Croatia. Clinical signs were firstly observed on November 2001 in sheep in Konavle, Dubrovnik – Neretva County. During this epizootic the overall sheep morbidity and mortality were 5.2% (95% confidence interval (c.i.), 4.1-6.6%) and 2.29% (95% c.i., 1.6-3.3%), respectively. After the outbreak, 3,318 serum samples of ruminants from 53 villages of the Dubrovnik – Neretva County were examined for bluetongue virus (BTV) antibodies by competitive enzyme-linked immunosorbent assay (cELISA). In forty nine (92.45%, 95% c.i., 82.11-96.92%) of the 53 villages, animals with antibodies against bluetongue virus were found. In particular, a total of 178 cattle (49.86%, 95% c.i., 44.7-55.0%), 174 sheep (13.72%, 95% c.i., 11.9-15.7%) and 270 goats (15.95%, 95% c.i., 14.3-17.8%) were seropositive. Antibodies to bluetongue virus serotype 9 were detected in 212 positive sera by serum neutralization test. The percentage of positive animals decreased (P > 0.05) from the east to the west suggesting a possible east westward spreading of BTV infection. Fourteen light-trap midge collections from seven different sites were examined. Of the 4872 Culicoides spp. collected, 4,492 (92%, 95% c.i., 91.4-92.9%) of them belonged to the species of Obsoletus complex. This study showed for the first time that a pathogenic strain of BTV-9, probably from Montenegro, entered Croatia causing disease and death in local sheep and that C. obsoletus and C. scoticus were likely the major vectors of infection.


2019 ◽  
Vol 39 (1) ◽  
pp. 25-31
Author(s):  
Pomy C.P. Kim ◽  
Renata P.B. Melo ◽  
Jonatas C. Almeida ◽  
José G. Silva ◽  
Muller Ribeiro-Andrade ◽  
...  

ABSTRACT: The present study aimed to measure the serological response of goats infected with Neospora caninum by assessing the diagnostic performance and agreement between three techniques (indirect immunofluorescent antibody test, IFAT; Neospora agglutitation test, NAT; enzyme-linked immunosorbent assay, ELISA). The panel of sera were comprised of 500 samples of goats, and 60 reference serum samples. These reference and field serum samples were tested by ELISA, NAT, and IFAT. In the field serum samples tested, the seroprevalences of anti-N. caninum antibodies were 3.2%, 4.6%, and 6.4% in the NAT, IFAT and ELISA, respectively. Using the IFAT as the gold standard, the NAT and the ELISA agreement was considered weak (k=0.28) and strong (k=0.75), respectively. When the IFAT performance was used for comparison purposes, the ELISA showed 91.3% sensitivity and 97.7%, specificity with a PPV of 65.2% and a NPV of 99.6%; The NAT presented sensitivity of 26.1% and specificity of 97.9% with a PPV of 37.5% and a NPV of 96.5%. Accordingly, the IFAT should remain the assay of choice for studies about N. caninum infection in goats in individual serum samples. A combination of serological assays with high sensitivity and specificity is recommended in serosurveys of caprine neosporosis.


Author(s):  
J.J.N. Ngeranwa ◽  
S.P. Shompole ◽  
E.H. Venter ◽  
A. Wambugu ◽  
J.E. Crafford ◽  
...  

The seroprevalence of Anaplasma antibodies in wildlife (eland, blue wildebeest, kongoni, impala, Thomson's gazelle, Grant's gazelle, giraffe and plains zebra) and domestic animal (cattle, sheep and goat) populations was studied in wildlife / livestock interface areas of Kenya. Serum samples were analyzed by competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA), using a recombinant antigen (MSP-5) from Anaplasma marginale surface membrane. A monoclonal antibody, FC-16, was used as the primary antibody, while anti-mouse conjugated to horseradish peroxidase was used as the secondary antibody. The results indicate a high seroprevalence in both wildlife and livestock populations, in contrast to earlier reports from Kenya, which indicated a low seroprevalence. The differences are attributed to the accurate analytical method used (CI-ELISA), as compared with agglutination techniques, clinical signs and microscopy employed by the earlier workers.


2000 ◽  
Vol 38 (11) ◽  
pp. 4010-4014 ◽  
Author(s):  
Baldev R. Gulati ◽  
Kjerstin T. Cameron ◽  
Bruce S. Seal ◽  
Sagar M. Goyal ◽  
David A. Halvorson ◽  
...  

The matrix (M) protein of avian pneumovirus (APV) was evaluated for its antigenicity and reliability in an enzyme-linked immunosorbent assay (ELISA) for diagnosis of APV infection, a newly emergent disease of turkeys in United States. Sera from APV-infected turkeys consistently contained antibodies to a 30-kDa protein (M protein). An ELISA based on recombinant M protein generated in Escherichia coli was compared with the routine APV ELISA that utilizes inactivated virus as antigen. Of 34 experimentally infected turkeys, 33 (97.1%) were positive by M protein ELISA whereas only 18 (52.9%) were positive by routine APV ELISA 28 days after infection. None of the serum samples from 41 uninfected experimental turkeys were positive by M protein ELISA. Of 184 field sera from turkey flocks suspected of having APV infection, 133 (72.3%) were positive by M protein ELISA whereas only 99 (53.8%) were positive by routine APV ELISA. Twelve serum samples, which were negative by M protein ELISA but positive by routine APV ELISA, were not reactive with either recombinant M protein or denatured purified APV proteins by Western analysis. This indicates that the samples had given false-positive results by routine APV ELISA. The M protein ELISA was over six times more sensitive than virus isolation (11.5%) in detecting infections from samples obtained from birds showing clinical signs of APV infection. Taken together, these results show that ELISA based on recombinant M protein is a highly sensitive and specific test for detecting antibodies to APV.


2021 ◽  
Vol 15 (12) ◽  
pp. e0010007
Author(s):  
Ulrich Wernery ◽  
Elaine Chan ◽  
Rekha Raghavan ◽  
Jade L. L. Teng ◽  
Ginu Syriac ◽  
...  

Glanders is a highly contagious and potentially serious disease caused by Burkholderia mallei, a Tier 1 select agent. In this study, we raised a monoclonal antibody (mAb) against the lipopolysaccharide (LPS) of B. mallei and developed a competitive enzyme-linked immunosorbent assay (cELISA) for B. mallei infection. Using the titrated optimal conditions of B. mallei-LPS (2 ng) for microtiter plate coating, sample serum dilution at 1:20 and 3.5 ng/μL anti-LPS mAb B5, the cutoff value of the cELISA was determined using serum samples from 136 glanders-free seronegative horses in Hong Kong. All calculated percentage inhibition (PI) values from these seronegative samples were below 39.6% inhibition (1.5 standard deviations above mean PI) and was used as the cutoff value. The diagnostic sensitivity of the developed LPS-based cELISA was first evaluated using sera from donkeys and mice inoculated with B. mallei. An increasing trend of PI values above the defined cELISA cutoff observed in the donkey and mouse sera suggested positive detection of anti-LPS antibodies. The sensitivity and specificity of the LPS-based cELISA was further evaluated using 31 serologically positive horse sera from glanders outbreaks in Bahrain and Kuwait, of which 30 were tested positive by the cELISA; and 21 seronegative horse sera and 20 seronegative donkey sera from Dubai, of which all were tested negative by the cELISA. A cELISA with high sensitivity (97.2%) and specificity (100%) for the detection of B. mallei antibodies in different animals was developed.


2020 ◽  
Vol 40 (4) ◽  
pp. 261-265
Author(s):  
Daniel A. Biihrer ◽  
Adriana S. Albuquerque ◽  
Adriana H.C.N. Romaldini ◽  
Edviges M. Pituco ◽  
Ana Carolina D. Matos ◽  
...  

ABSTRACT: Bluetongue is an infectious, non-contagious disease that affects domestic and wild ruminants, caused by a virus from the Orbivirus genus, Reoviridae family, transmitted by arthropod vectors of the Culicoides genus. This paper aims to be the first serological survey of bluetongue in sheep from the Meso-regions of Campo das Vertentes and South and Southeast of Minas Gerais. Samples were collected from sheep from different properties. The serum samples were submitted to Agar Gel Immunodiffusion (AGID) and competitive Enzyme-Linked Immunosorbent Assay (cELISA). 303 serum samples were submitted to AGID and cELISA. In these samples, 164 (54.13%) were positive in the AGID technique, and 171 (56.44%) positive in the cELISA technique, with an almost perfect agreement between the techniques (kappa index = 0.887). In all visited properties, positive animals have been found in the herd. Animals acquired from properties of the studied mesoregions were more likely to be positive in IDGA and cELISA tests than animals acquired from properties in other regions of Brazil (p<0.001). These results suggest that bluetongue virus (BTV) is widespread in the mesoregions of Campo das Vertentes and South and Southeast of Minas Gerais.


2020 ◽  
Author(s):  
Chenxi Li ◽  
Manyun Qian ◽  
Qiaozhen Hong ◽  
Xiaohong Xin ◽  
Zichun Sun ◽  
...  

Abstract Autoantibodies against M-type phospholipase A2 receptor (PLA2R) are specific biomarkers for idiopathic membranous nephropathy (IMN) and their quantification has been helpful to monitor disease activity. In this study, we describe a highly sensitive and rapid quantum dots-based immunochromatography assay (QD-ICA) for quantifying PLA2R autoantibodies. Serum samples from 135 biopsy-confirmed patients with nephrotic syndrome were analyzed for PLA2R autoantibodies using the novel QD-ICA as well as enzyme-linked immunosorbent assay (ELISA). The detection sensitivity and specificity of QD-ICA (80.9 and 100%, respectively) exceeded those of ELISA (72.1 and 98.5%, respectively). The optimum cut-off value of QD-ICA was 18.18 RU/mL and limit of detection was 2.86 relative units/mL. The novel QD-ICA outperforms ELISA in detecting PLA2R autoantibodies, with shorter detection time, fewer steps, smaller equipment size, and broader testing application, suggesting its capability to improve IMN diagnosis and monitor patient response to treatment.


Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 303
Author(s):  
Wei-Ting Hsu ◽  
Chia-Yu Chang ◽  
Chih-Hsuan Tsai ◽  
Sung-Chan Wei ◽  
Huei-Ru Lo ◽  
...  

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes serious and highly contagious enteric disease in swine worldwide. In this study, we constructed a recombinant baculovirus (S-Bac) expressing full-length spike protein of the virulent epidemic genotype 2b (G2b) PEDV strain for serological studies of infected pigs. We found that most spike-specific antibodies produced upon PEDV infection in pigs are conformation-specific and they could be detected on S-Bac-infected insect cells by immunofluorescent assay, but they were insensitive to Western blot analysis, the typical method for antiserum analysis. These results indicated that spike conformation is crucial for serum recognition. Since it is difficult to purify trimeric spike membrane protein for conventional enzyme-linked immunosorbent assay (ELISA), we used S-Bac to generate a novel cell-based ELISA for convenient PEDV detection. We analyzed 100 pig serum samples, and our cell-based ELISA exhibited a sensitivity of 100%, a specificity of 97%, and almost perfect agreement [Cohen’s kappa coefficient value (κ) = 0.98] with immunocytochemical staining results. Our cell-based ELISA rapidly presented antigen for proper detection of conformation-specific antibodies, making PEDV detection more convenient, and it will be useful for detecting many viral diseases in the future.


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