Molecular characterization of circulating strains of small ruminant lentiviruses in Brazil based on complete gag and pol genes

Azevedo, Dalva Alana Aragão de; Monteiro, J. P.; Pinheiro, R. R.; Mudadu, Mauricio de Alvarenga; Andrioli, A.; Araújo, Juscilânia Furtado; Sousa, Ana Lídia Madeira de; Sider, L. H.; Peixoto, Renato Mesquita; Teixeira, Maria Fátima da Silva

doi:10.1016/j.smallrumres.2019.06.011

Cited by 9 publications

(10 citation statements)

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“…As also shown by others [12,43,[54][55][56][57][58][59][60][61][62], the resulting LTR sequence fragments of this work allowed quite a robust and plausible phylogentic reconstruction of the taxonomy of lentiviruses detected in the samples originating from a number of Western European countries. Sequencing of the whole genome or other fragments thereof to exclude homologous recombination could be a useful complementation for future work.…”

Section: Discussionsupporting

confidence: 61%

Evaluation of Serological Methods and a New Real-Time Nested PCR for Small Ruminant Lentiviruses

et al. 2022

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Small ruminant lentiviruses (SRLVs), i.e., CAEV and MVV, cause insidious infections with life-long persistence and a slowly progressive disease, impairing both animal welfare and productivity in affected herds. The complex diagnosis of SRLVs currently combines serological methods including whole-virus and peptide-based ELISAs and Immunoblot. To improve the current diagnostic protocol, we analyzed 290 sera of animals originating from different European countries in parallel with three commercial screening ELISAs, Immunoblot as a confirmatory assay and five SU5 peptide ELISAs for genotype differentiation. A newly developed nested real-time PCR was carried out for the detection and genotype differentiation of the virus. Using a heat-map display of the combined results, the drawbacks of the current techniques were graphically visualized and quantified. The immunoblot and the SU5-ELISAs exhibited either unsatisfactory sensitivity or insufficient reliability in the differentiation of the causative viral genotype, respectively. The new truth standard was the concordance of the results of two out of three screening ELISAs and the PCR results for serologically false negative samples along with genotype differentiation. Whole-virus antigen-based ELISA showed the highest sensitivity (92.2%) and specificity (98.9%) among the screening tests, whereas PCR exhibited a sensitivity of 75%.

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Section: Discussionsupporting

confidence: 61%

Evaluation of Serological Methods and a New Real-Time Nested PCR for Small Ruminant Lentiviruses

et al. 2022

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“…Using a specific primer targeting the pol gene, the PCR method is a gold standard and fast method for the detection of CAEV in PBMCs from infected goats [ 15 , 16 ]. DNA extracted from PBMCs was used as templates, with recorded sensitivities ranging from 70% to 95% [ 17 , 18 ].…”

Section: Discussionmentioning

confidence: 99%

First study on the molecular prevalence of caprine arthritis encephalitis virus in goats in Babylon, Iraq

2022

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Background and Aim: Caprine arthritis encephalitis virus (CAEV) is a virus that affects goats all over the world and causes enormous economic losses; as a result, screening for the disease is a priority, especially in Iraq. The present study aimed to estimate the prevalence of CAEV in infected goats using the précised PCR method in Babylon, Iraq. Materials and Methods: A total of 85 blood samples from goats aged 1 month to ≥6 years were analyzed for CAEV infections using molecular methods. The polymerase chain reaction primer was designed to amplify a 573 bp region of the proviral pol gene. Results: The CAEV tests revealed that five out of 85 goats were positive for CAEV. There were no significant differences in CAEV infection according to goat sex and significant differences according to age. Conclusion: Based on these results, the present study is the first molecular survey to confirm the current CAEV genome in an Iraqi goat flock.

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“…A reação imunoenzimática é utilizada para detecção de proteínas imunogênicas de importância para o diagnóstico viral. Essas proteínas imunogênicas, são provenientes de genes que são de suma importância no diagnóstico molecular [11,26].…”

Section: Western Blot: Conceitos Básicos E Aplicaçõesunclassified

Western Blot in Immunodiagnosis of Small Ruminant Lentivirus

Peixoto

Araújo

Pinheiro

2021

Acta Scientiae. Vet.

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Background: Small ruminant lentiviruses (SRLV) belong to genus Lentivirus, family Retroviridae. These viruses cause caprine arthritis encephalitis (CAE) and maedi visna (MV), infectious diseases that cause economic, production, and reproductive losses. There are no effective treatments or vaccines for these diseases. Thus, early detection via serology has great importance for control of SRLV. Therefore, the objective of this review is to demonstrate the potential of the western blot (WB) test as an immunodiagnostic test for SRLV. Review: In general, immunodiagnosis of SRLV is performed via agar gel immunodiffusion (AGID) and indirect enzyme-linked immunosorbent assay (ELISA), which can detect antibodies in several different biological samples but is used preferably with serum and blood plasma. However, WB has demonstrated efficacy in the early diagnosis of immunoglobulins against SRLV, presenting higher sensitivity and specificity than the serological tests usually used, because this technique can detect antibodies at a dilution as much as 256 times greater than that of AGID and 32 times greater than that of ELISA. SRLV infection and consequent immunological activation result in the induction of cellular and humoral responses. Additionally, around the third week, production of antibodies directed mainly toward viral capsid proteins (p25 and p28) occurs. After the fifth week, production of immunoglobulins directed toward other viral proteins occurs. Because of the persistence of SRLV infection, serology is considered to be the most practical means to diagnosis. Each serological test has a percentage specificity and distinct sensitivity, as well as advantages and disadvantages in its applicability. It should be noted that there is no gold standard test for diagnosis of SRLV infection. Moreover, SRLV are characterized by escape mechanisms such as genetic diversity, mutagenic potential, viral intermittence, and the process of compartmentalization, which make immunodiagnosis more difficult. In addition, positive animals tend to present unstable levels of antibodies over weeks, months, and even years. In this context, WB, with early antibody detection, has been proven to be a refined and more accurate technique than other immunodiagnostic tests for SRLV. WB allows the simultaneous resolution of several immunogenic antigens present in a sample, and this feature provides it with greater reliability, differentiates it from other immunological methods, and accredits it as a test of wide applicability. Epidemiological and immunological dynamics studies often use WB in the immunodynamic diagnosis of SRLV. Serum, blood plasma, and seminal plasma are typical biological materials used in the serological diagnosis of SRLV with WB, expanding its potential as an immunodiagnosis method.Conclusion: WB is the most accurate serological technique for SRLV. It is more capable of accurate diagnosis because the genetic diversity that characterizes such lentiviruses and their various immune system escape mechanisms routinely hinder traditional diagnosis. Additionally, this test has been used widely in studies of SRLV for various purposes, but mainly in studies of epidemiological and immunological dynamics, using serum, blood plasma, or seminal plasma. However, independently of the biological sample tested, WB maintains high sensitivity and precision in immunodiagnosis, making it a refined and valid technique for SRLV control programs.

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Molecular characterization of circulating strains of small ruminant lentiviruses in Brazil based on complete gag and pol genes

Cited by 9 publications

References 32 publications

Evaluation of Serological Methods and a New Real-Time Nested PCR for Small Ruminant Lentiviruses

Evaluation of Serological Methods and a New Real-Time Nested PCR for Small Ruminant Lentiviruses

First study on the molecular prevalence of caprine arthritis encephalitis virus in goats in Babylon, Iraq

Western Blot in Immunodiagnosis of Small Ruminant Lentivirus

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