scholarly journals Evaluation of a New Antibody-Based Enzyme-Linked Immunosorbent Assay for the Detection of Bovine Leukemia Virus Infection in Dairy Cattle

2005 ◽  
Vol 17 (5) ◽  
pp. 451-457 ◽  
Author(s):  
Gustavo E. Monti ◽  
Klaas Frankena ◽  
Bas Engel ◽  
Willem Buist ◽  
Héctor D. Tarabla ◽  
...  
Keyword(s):  
Maximum Likelihood ◽  
Dairy Cattle ◽  
Immunosorbent Assay ◽  
Bovine Leukemia Virus ◽  
Conditional Independence ◽  
Latent Class ◽  
Leukemia Virus ◽  
Latent Class Model ◽  
Enzyme Linked Immunosorbent Assay ◽  
Conditional Dependence

The objective of this study was to validate a new blocking enzyme-linked immunosorbent assay (ELISA) (designated M108 for milk and S108 for serum samples) for detecting bovine leukemia virus (BLV) infection in dairy cattle. Milk, serum, and ethylenediaminetetraacetic acid–blood samples were collected from 524 adult Holstein cows originating from 6 dairy herds in Central Argentina. The M108 and S108 were compared with agar gel immunodiffusion (AGID), polymerase chain reaction and a commercial ELISA. Because there is currently no reference test capable of serving as a gold standard, the test sensitivity (SE) and specificity (SP) were evaluated by the use of a latent class model. Statistical inference was performed by classical maximum likelihood and by Bayesian techniques. The maximum-likelihood analysis was performed assuming conditional independence of tests, whereas the Bayesian approach allowed for conditional dependence. No clear conclusion could be drawn about conditional dependence of tests. Results with maximum likelihood (under conditional independence) and posterior Bayes (under conditional dependence) were practically the same. Conservative estimates of SE and SP (with 95% confidence intervals) for M108 were 98.6 (96.7; 99.6) and 96.7 (92.9; 98.8) and for S108 99.5 (98.2; 99.9) and 95.4 (90.9; 98.1), respectively. The ELISA 108 using either milk or serum to detect BLV-infected animals had comparable SE and SP with the official AGID and a commercial ELISA test, which are currently the most widely accepted tests for the serological diagnosis of BLV infection. Therefore, ELISA 108 can be used as an alternative test in monitoring and control programs.

scholarly journals Bayesian evaluation of three serological tests for the diagnosis of bovine brucellosis in Bangladesh

2019 ◽  
Vol 147 ◽  
Author(s):  
A. K. M. A. Rahman ◽  
S. Smit ◽  
B. Devleesschauwer ◽  
P. Kostoulas ◽  
E. Abatih ◽  
...  
Keyword(s):  
Latent Class ◽  
Latent Class Model ◽  
Dairy Farm ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bovine Brucellosis ◽  
Class Model ◽  
Serological Tests ◽  
Predictive Values ◽  
Conditional Dependence

AbstractWe evaluated the performance of three serological tests – an immunoglobulin G indirect enzyme linked immunosorbent assay (iELISA), a Rose Bengal test and a slow agglutination test (SAT) – for the diagnosis of bovine brucellosis in Bangladesh. Cattle sera (n = 1360) sourced from Mymensingh district (MD) and a Government owned dairy farm (GF) were tested in parallel. We used a Bayesian latent class model that adjusted for the conditional dependence among the three tests and assumed constant diagnostic accuracy of the three tests in both populations. The sensitivity and specificity of the three tests varied from 84.6% to 93.7%, respectively. The true prevalences of bovine brucellosis in MD and the GF were 0.6% and 20.4%, respectively. Parallel interpretation of iELISA and SAT yielded the highest negative predictive values: 99.9% in MD and 99.6% in the GF; whereas serial interpretation of both iELISA and SAT produced the highest positive predictive value (PPV): 99.9% in the GF and also high PPV (98.9%) in MD. We recommend the use of both iELISA and SAT together and serial interpretation for culling and parallel interpretation for import decisions. Removal of brucellosis positive cattle will contribute to the control of brucellosis as a public health risk in Bangladesh.

scholarly journals Expression of the Bovine Leukemia Virus Envelope Glycoprotein (gp51) by Recombinant Baculovirus and Its Use in an Enzyme-Linked Immunosorbent Assay

2004 ◽  
Vol 11 (1) ◽  
pp. 147-151 ◽  
Author(s):  
Antonio De Giuseppe ◽  
Francesco Feliziani ◽  
Domenico Rutili ◽  
Gian Mario De Mia
Keyword(s):  
Immunosorbent Assay ◽  
Envelope Glycoprotein ◽  
Bovine Leukemia Virus ◽  
Signal Sequence ◽  
Leukemia Virus ◽  
Recombinant Baculovirus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Envelope ◽  
Gene Encoding ◽  
Field Samples

ABSTRACT The gene encoding the major envelope glycoprotein (gp51) with its signal sequence, represented by an additional NH2-terminal 33-residue amino acid sequence of bovine leukemia virus (BLV), was inserted into a baculovirus transfer vector. A recombinant virus expressing a secreted gp51 protein in insect cells was isolated. The recombinant gp51 expressed was characterized by using an anti-BLV monoclonal antibody by both Western blotting analysis and enzyme-linked immunosorbent assay (ELISA). The secreted gp51 was used as an antigen, and an ELISA with recombinant gp51 (rgp51) was developed for the detection of BLV antibodies. This new procedure was compared with a previous ELISA method for the detection of BLV antibodies and an agar gel immunodiffusion test performed with an unpurified BLV antigen preparation. The comparative testing of field samples showed that the ELISA with rgp51 is more specific and also suitable for the testing of pooled sera.

scholarly journals Bayesian Estimation of the True Seroprevalence and Risk Factor Analysis of Bovine Leukemia Virus Infection in Pakistan

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1404
Author(s):  
Ali Sakhawat ◽  
Marzena Rola-Łuszczak ◽  
Zbigniew Osiński ◽  
Nazia Bibi ◽  
Jacek Kuźmak
Keyword(s):  
Risk Factor ◽  
Dairy Cattle ◽  
Bovine Leukemia Virus ◽  
Water Buffalo ◽  
Leukemia Virus ◽  
Credible Interval ◽  
Indigenous Cattle ◽  
Herd Level ◽  
Exotic Breed ◽  
Posterior Estimate

The objective of this study was to determine the true seroprevalence of bovine leukemia virus (BLV) infection in dairy cattle from Pakistan at the animal and herd-level. We tested 1380 dairy cattle from 451 herds and 92 water buffalo. The sera were tested by ELISA and the results were analyzed using Bayesian inference. The median posterior estimate of the herd level true BLV prevalence was 1.4%, with a 95% credible interval (CI) 0.7–3.1, whereas the median posterior estimate of the within-farm true seroprevalence was 3.8% with a 95% CI 2.8–4.8. All 92 sera collected from water buffalo were negative. Several risk factors potentially associated with seropositivity to BLV infections in Pakistan were analyzed using logistic regression model based on calculation of an odds ratio (OR). The study showed an association between seropositivity and medium herd (≥50) size (OR = 23.57, 95% CI: 3.01–103.48). Common housing of indigenous cattle with exotic-breed cattle (OR = 0.67, 95% CI: 06–2.35) or housing indigenous or their crossbred cattle with exotic-breed cattle (OR = 0.95, 95% CI: 0.14–3.01) had no effect on the BLV seroprevalence. Similarly, common housing of cattle and water buffalo was not risk factor for increased BLV seropositivity (OR = 27.10, 95% CI: 0.63–119.34).

scholarly journals The hematobiochemical status of Wistar rat line under the bovine leukemia virus experimental infection

2019 ◽  
Vol 12 (3) ◽  
pp. 382-388
Author(s):  
Ekaterina Sergeevna Krasnikova ◽  
Fayssal Bouchemla ◽  
Alexander Vladimirovich Krasnikov ◽  
Roman Vladimirovich Radionov ◽  
Anastasia Sergeevna Belyakova
Keyword(s):  
Bovine Leukemia Virus ◽  
Wistar Rats ◽  
Blood Platelets ◽  
Leukemia Virus ◽  
Wistar Rat ◽  
Laboratory Model ◽  
Enzyme Linked Immunosorbent Assay ◽  
Endocrine Disorders ◽  
Adult Rats ◽  
Group I

Aim: This study aimed to elucidate the ability of the bovine leukemia virus (BLV) to integrate into cells of heterologous organisms, in particular, Wistar rats, and examine the manifestations of the pathological process that could be seen in them. Materials and Methods: Wistar rats - were divided into three groups. The first group (I) was fed milk of intact cows, the second (II) - milk of BLV-infected cows, and the third (III) - milk of cows, clinically BLV sick. Rats of all groups were divided into two subgroups: In the subgroup "a", there were adult rats, and in the subgroup "b", their offspring were included. At 3, 6, 9, and 12 months from the start of the experiment, the animals' blood of each group was examined by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay for the presence of BLV provirus and specific anti-leukemia antibodies. A general and biochemical blood test was performed; pathological changes in the internal organs were recorded. Results: Using the PCR, the BLV infection was established in all experimental rats, whose immune response was expressed in varying degrees. At the initial stage of the infection, offspring rats were born healthy. The rats of the control groups Ia and Ib were intact to the BLV throughout the experiment. The biochemical blood tests have shown several signs of intoxication, endocrine disorders, and development of malignant processes in the experimental animals. There are also signs of liver, kidney, and myocardial damages, regardless of whether milk is infected or the cows are clinically leukemic. By the time, the experimental rats developed persistent thrombocytosis with an increase in the average volume of the blood platelets, which may be evidence of the leukemia infection by the megakaryocytic type. The most pronounced character of the change was in the offspring generation. Conclusion: Wistar rats can be considered as a suitable laboratory model to study the BLV pathogenesis. Rats are not BLV natural host, however, they developed the pathognomonic BLV infection symptoms when they were fed infected and leukemic cow's milk.

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