Caprine Lentivirus Research Articles

In vitro antiviral effect of ethanolic extracts from Azadirachta indica and Melia azedarach against goat lentivirus in colostrum and milk

This study aimed to evaluate, in vitro, the use of leaf extracts of Azadirachta indica (A. indica) and Melia azedarach (M. azedarach) as antivirals against caprine lentivirus (CLV) in colostrum and milk of goat nannies. These were collected from eight individuals and infected with the standard strain of CLV. Samples were then subdivided into aliquots and treated with 150 µg/mL of crude extract, and with ethyl acetate and methanol fractions for 30, 60, and 90 min. Next, somatic cells from colostrum and milk were co-cultured with cells from the ovine third eyelid. After this step, viral titers of the supernatants collected from treatments with greater efficacy in co-culture were assessed. The organic ethyl acetate fractions of both plants at 90 min possibly inhibited the viral activity of CLV by up to a thousandfold in colostrum. In milk, this inhibition was up to 800 times for the respective Meliaceae. In conclusion, the ethanolic fraction of ethyl acetate from both plants demonstrated efficacy against CLV in samples from colostrum and milk when subjected to treatment, which was more effective in colostrum.

Seroprevalence and associated risk factors of Mycoplasma agalactiae and investigation of coinfection with the caprine lentivirus in Rio Grande do Norte, Brazil.

Contagious agalactia is a disease caused by Mycoplasma agalactiae that leads to a reduction or complete stop of milk production. Caprine arthritis encephalitis (CAE) is an infectious disease caused by a lentivirus of the Retroviridae family, member of the small ruminant lentivirus (SRLV) group. Although these diseases are caused by distinct pathogens, the clinical presentation is similar. Hence, this study aimed to perform a serological investigation, as well as to assess correlation between both diseases and risk factors associated in two mesoregions of Rio Grande do Norte, Brazil. Enzyme-linked immunosorbent assay (ELISA) was used for contagious agalactia and western blot for CAE. A total of 538 serum samples were used in this study that were collected from goats and sorted from a blood bank of the Brazilian Agricultural Research Corporation. Seroprevalence of M. agalactiae in flocks from Rio Grande do Norte was 7.8% (42/538). In both regions that were investigated, 25.9% (14/54) of farms had positive animals. CAE results revealed that 3.9% (21/538) of animals and 42.6% (23/54) of farms had this disease. Concerning risk factors, only sex and animal category presented significant relevance (P < 0.05) for contagious agalactia, in which females presented higher frequency of seropositive individuals (10.1%; 39/387). In the animal category, 4.3% (14/326) and 11.1% (36/323) of female breeders were positive for CAE and contagious agalactia, respectively, and significance was identified only in the latter (P < 0.05). In conclusion, there was no correlation between the investigated diseases, considering that no animal demonstrated antibodies for both pathogens.

Sodium dodecyl sulfate as a viral inactivator and future perspectives in the control of small ruminant lentiviruses

ABSTRACT Infections by small ruminant lentiviruses (SRLVs) affect goats and sheep causing chronic multisystemic diseases that generate great economic losses. The caprine lentivirus (CLV) and the ovine lentivirus (OLV) present tropism for cells of the monocyte/macrophage lineage, which are directly associated with the main route of transmission through the ingestion of milk and colostrum from infected animals. In this manner, controlling this route is of paramount importance. Currently, researches have investigated the use of chemical additives in milk that can preserve colostrum or milk and inactivate microbiological agents. Among the compounds, sodium dodecyl sulfate (SDS) has been shown to be satisfactory in the chemical inactivation of HIV and CLV in milk, and also as a biocide in goat colostrum.

In vitro and in vivo evaluation of sodium dodecyl sulfate (SDS) as an inactivator of caprine lentivirus (CLV) in colostrum and milk

ABSTRACT The aim of this study was to evaluate in vitro and in vivo the effect of sodium dodecyl sulfate (SDS) on the caprine lentivirus (CLV) in colostrum and milk. This was performed to develop a practical and efficient method of blocking the lactogenic transmission of the virus. In the in vitro experiment, colostrum and milk were treated with 0.25%; 0.50% and 1% SDS. Then, somatic cells of colostrum and milk were submitted to co-culture with caprine synovial membrane cells (CSM). In the in vivo test, goats were fed with colostrum and milk provided from CLV-positive goats treated with SDS in the same concentrations used in the in vitro experiment. Animals were tested by nested polymerase chain reaction (nPCR) and Western blot (WB) assays. In the in vitro experiment, inhibitory activity against CLV without inactivation occurred in colostrum with all SDS concentrations. However, concentrations of 0.25 and 0.5% SDS presented only inhibitory activity against CLV in milk cells, and 1% concentration provided inactivation of the virus. In the in vivo tests, none of the three concentrations of SDS was effective in inactivating LVC in colostrum or goat milk, which was confirmed by seroconversion and presence of proviral DNA in animals afterwards.

Mycoplasma agalactiae in Dairy Goat Flocks Bred in State of Ceará in Association with Caprine Arthritis Encephalitis Virus

Background: Contagious agalactia is an infectious disease caused by Mycoplasma agalactiae (M. agalactiae) that occurs in small ruminants leading to productive and economic losses. Due to the similarity of clinical signs presented in Caprine Arthritis Encepha­litis (CAE), which is a viral disease, a differential diagnosis is important. Therefore, this study aimed to investigate the presence of anti-Mycoplasma agalactiae antibodies in dairy goat flocks in Ceará State and possible correlation with CAE.Materials, Methods &amp; Results: The research was performed in four mesoregions in Ceará State (Metropolitan Region of Fortaleza- MRF; Northeast Ceará - NeC; North Ceará - NC; Sertões in Ceará - SC), from which 16 productions located in 10 cities with the highest representativeness for goat milk production within the State or mesoregion were sampled. A total of 417 females and 69 males (486 animals) of breeds with dairy production aptitude, pure or crossbreed, maintained in semi-intensive or intensive systems, were tested. Blood serum was obtained by venipuncture of the jugular vein with vacuum pressure syringe followed by centrifugation at 1,500 g for 10min. Antibodies against the caprine arthritis encephalitis virus (CAEV) were detected with micro technique of agarose gel immunodiffusion (AGID) and Western Blot (WB). The anti-Mycoplasma agalactiae antibodies were detected with commercial kit of enzymatic immunoassay (IDEXX Laboratories™). Seroprevalence of M. agalactiae in dairy goat flocks in Ceará State was 0.62% (3/486). From the total of 16 visited productions, 18.75% (3/16) had seropositive animals for M. agalactiae located in MRF, NC and SC mesoregions. CAE was diagnosed in 56.25% (9/16) of productions with AGID and in 81.25% (13/16) with WB. In addition, 5.2% (25/486) of animals were seropositive for CAE with AGID and 16.6% (80/486) with WB. Animals that reacted positive for M. agalactiae were all females of pure breed with milk production aptitude in distinct mesoregions submitted to intensive rearing system. None of these animals was positive in neither test (AGID or WB) for CAE. Therefore, no correlation of results obtained in diagnosis of M. agalactiae by ELISA and CAEV by AGID or WB (P &lt; 0.05) was identified. However, two out of three productions that were positive for M. agalactiae presented positive results for CAEV with frequencies of 10% and 20%.Discussion: Seroprevalence of M. agalactiae in Ceará State was low in comparison with other Brazilian states and even other countries. However, the presence of the pathogen in more than one mesoregion indicates that the disease occurs in different loca­tions within the State. Therefore, flocks in Ceará are susceptible to the infection, which may be favored by uncontrolled commerce that occurs with deficient surveillance, associated with the importation of animals to improve flock genetic quality. The presence of the pathogen in dairy goats may contribute to significant losses in the local production. On the other hand, CAE was diagnosed in nearly all productions proving the dissemination of this lentivirus infection among dairy goat flocks in Ceará State. Although an association between these diseases was not identified, the presence of a retrovirus in the organism may favor co-infection with another micro-organism, promoting the deficiency in the immune system of the host. In conclusion, M. agalactiae is present in different mesoregions of the Ceará State and control measures should be adopted in short term to prevent pathogen dissemination and, consequently reduce economic and productive losses in the local dairy goat production. No correlation was identified between the prevalence of infection by CAEV and M. agalactiae in this study.Keywords: correlation, diagnosis, caprine lentivirus, mycoplasmosis.

Mycoplasma agalactiae in Dairy Goat Flocks Bred in State of Ceará in Association with Caprine Arthritis Encephalitis Virus

Background: Contagious agalactia is an infectious disease caused by Mycoplasma agalactiae (M. agalactiae) that occurs in small ruminants leading to productive and economic losses. Due to the similarity of clinical signs presented in Caprine Arthritis Encephalitis (CAE), which is a viral disease, a differential diagnosis is important. Therefore, this study aimed to investigate the presence of anti-Mycoplasma agalactiae antibodies in dairy goat flocks in Ceará State and possible correlation with CAE.Materials, Methods &amp; Results: The research was performed in four mesoregions in Ceará State (Metropolitan Region of Fortaleza-MRF; Northeast Ceará - NeC; North Ceará - NC; Sertões in Ceará - SC), from which 16 productions located in 10 cities with the highest representativeness for goat milk production within the State or mesoregion were sampled. A total of 417 females and 69 males (486 animals) of breeds with dairy production aptitude, pure or crossbreed, maintained in semi-intensive or intensive systems, were tested. Blood serum was obtained by venipuncture of the jugular vein with vacuum pressure syringe followed by centrifugation at 1,500 g for 10min. Antibodies against the caprine arthritis encephalitis virus (CAEV) were detected with micro technique of agarose gel immunodiffusion (AGID) and Western Blot (WB). The anti-Mycoplasma agalactiae antibodies were detected with commercial kit of enzymatic immunoassay (IDEXX Laboratories™). Seroprevalence of M. agalactiae in dairy goat flocks in Ceará State was 0.62% (3/486). From the total of 16 visited productions, 18.75% (3/16) had seropositive animals for M. agalactiae located in MRF, NC and SC mesoregions. CAE was diagnosed in 56.25% (9/16) of productions with AGID and in 81.25% (13/16) with WB. In addition, 5.2% (25/486) of animals were seropositive for CAE with AGID and 16.6% (80/486) with WB. Animals that reacted positive for M. agalactiae were all females of pure breed with milk production aptitude in distinct mesoregions submitted to intensive rearing system. None of these animals was positive in neither test (AGID or WB) for CAE. Therefore, no correlation of results obtained in diagnosis of M. agalactiae by ELISA and CAEV by AGID or WB (P &lt; 0.05) was identified. However, two out of three productions that were positive for M. agalactiae presented positive results for CAEV with frequencies of 10% and 20%.Discussion: Seroprevalence of M. agalactiae in Ceará State was low in comparison with other Brazilian states and even other countries. However, the presence of the pathogen in more than one mesoregion indicates that the disease occurs in different locations within the State. Therefore, flocks in Ceará are susceptible to the infection, which may be favored by uncontrolled commerce that occurs with deficient surveillance, associated with the importation of animals to improve flock genetic quality. The presence of the pathogen in dairy goats may contribute to significant losses in the local production. On the other hand, CAE was diagnosedin nearly all productions proving the dissemination of this lentivirus infection among dairy goat flocks in Ceará State. Although an association between these diseases was not identified, the presence of a retrovirus in the organism may favor co-infection with another micro-organism, promoting the deficiency in the immune system of the host. In conclusion, M. agalactiae is present in different mesoregions of the Ceará State and control measures should be adopted in short term to prevent pathogen dissemination and, consequently reduce economic and productive losses in the local dairy goat production. No correlation was identified between the prevalence of infection by CAEV and M. agalactiae in this study.Keywords: correlation, diagnosis, caprine lentivirus, mycoplasmosis.

Evaluation of Solvent Toxicity of Plant Extract with Antiviral Action in Refrigerated Goat Semen

Background: Caprine Arthritis Encephalitis Virus have been detected in sperm of breeding goats causing economic losses. In order to control the virus, researches aiming to identify natural extracts with potential antiviral effects are performed. However, aqueous or ethanolic extracts must be diluted in dimethyl sulfoxide (DMSO), which is a substance with unknown effects in sperm quality when present in diluting media. Therefore, this study aimed to evaluate sperm viability of refrigerated caprine semen diluted in media containing DMSO. This was performed to provide data that aid in researches involving the use of this component with natural extracts that may inactivate the caprine lentivirus in sperm.Materials, Methods &amp; Results: The experiment was performed at the Laboratory of Seminal Technology in Embrapa Goats and Sheep in the city of Sobral, Brazil. Sperm viability was assessed in caprine semen refrigerated in two dilution media with crescent concentrations of DMSO. Sperm samples of five goats seronegative for the caprine lentivirus were pooled and diluted in minimal essential medium (MEM) enriched with glucose at 0.01 M added of crescent concentrations of DMSO (0%, 1.5%, 1.75%, 2.0%, 2.25% and 2.5%). The same breeders provided the pool of sperm to test Tris added 2.5% of egg yolk and the same concentrations of DMSO previously mentioned. Treatments were refrigerated at 7°C and evaluated up until four h after DMSO addition. Individual progressive motility (MIP), sperm vigor (V), percentage of spermatozoa reactive to hypoosmotic test (HO) and morphologically normal (NOR) were evaluated. IPM, vigor and NOR remained within normal standards for the caprine species in all treatments test. Percentage results of spermatozoa reactive to hypoosmotic was higher in Tris yolk with values ranging between 34.66% to 46.33%. Sperm vigor was positively correlated (r = 0.85) with IPM in the MEM diluted pool of sperm. In Tris yolk, vigor and hypoosmotic test correlated moderately (r = 0.63, r = 0.54, respectively) with IPM. Tris yolk medium added DMSO presented the highest percentage of reactivity to hypoosmotic test in all treatments when compared to MEM added DMSO.Discussion: The fact that DMSO is easily homogenized in water, ethylic alcohol and most organic solvents favors its use in diluting natural extracts. These components are a possible source of products that inactivate caprine arthritis encephalitis virus in sperm, which is the key to promoting the safe use of genetic material of infected breeders, in addition to commercial use of germplasm. In this study, there was no interference of DMSO in the analyzed parameters when added in a maximum concentration of 2.5% to MEM and Tris yolk, which is in accordance with standard values for goats. In addition, Tris yolk may promote greater protection to the membrane of sperm cells, which was demonstrated by hypoosmotic test. This medium could be ideal to be used in new methodologies that incorporate DMSO. In conclusion, DMSO added to dilution media Tris yolk and MEM did not interfere with the quality of refrigerated caprine sperm, which maintained viability. These results indicate that this substance did not present harmful effects to the genetic material, promoting the use as solvent of extracts from plant compounds with potential anti-viral effect. The information in this study may aid new research performed in this area.

Caprine lentivirus in sheep milk and semen

ABSTRACT With the objective of detecting the presence of caprine lentivirus (CLV) in ewe milk and in ram semen, ten matrixes and four reproducers experimentally infected with CLV were used. Samples of ewe milk were collected during the four months of lactation, five collections per animal, totaling 50 samples. Regarding the rams, eight semen collections were made per animal, during one year of experimentation, totaling 32 samples. The milk and semen samples were submitted to DNA extraction and the nested polymerase chain reaction test (nPCR) to detect CLV proviral DNA. Eight (16%) of the milk samples were positive in nPCR originating from two ewes. Only one (3.12%) semen sample was positive. The amplification products were sequenced, and were confirmed to be a CLV genomic sequence. Thus, the presence of CLV proviral DNA in sheep milk and semen was demonstrated, confirming the feasibility of infection between species, and alerting to the risk of spreading infections.

Interspecific transmission of small ruminant lentiviruses from goats to sheep.

This study was conducted in order to evaluate the transmission of caprine lentivirus to sheep using different experimental groups. The first one (colostrum group) was formed by nine lambs receiving colostrum from goats positive for small ruminant lentiviruses (SRLV). The second group (milk group) was established by nine lambs that received milk of these goats. Third was a control group, consisting of lambs that suckled colostrum and milk of negative mothers. Another experimental group (contact group) was formed by eight adult sheep, confined with two naturally infected goats. The groups were monitored by immunoblotting (IB), enzyme-linked immunosorbent assay (ELISA), agar gel immunodiffusion (AGID) and nested polymerase chain reaction (nPCR). All lambs that suckled colostrum and milk of infected goats and six sheep of the contact group had positive results in the nPCR, although seroconversion was detected only in three of the exposed animals, with no clinical lentiviruses manifestation, in 720 days of observation. There was a close relationship between viral sequences obtained from infected animals and the prototype CAEV-Cork. Thus, it was concluded that SRLV can be transmitted from goats to sheep, however, the degree of adaptation of the virus strain to the host species probably interferes with the infection persistence and seroconversion rate.

Molecular characterization of the gag gene of caprine arthritis encephalitis virus from goats in the Philippines.

Caprine arthritis encephalitis virus (CAEV) causes caprine arthritis encephalitis syndrome, which is an emerging disease of goats in the Philippines. DNA sequence analysis showed homology of 86-93% between Philippine CAEV and available CAEV sequences in GenBank. CAEV was detected using nested polymerase chain reaction (PCR), and new sets of primers were designed in order to amplify the gag gene, which is a highly conserved region of the viral genome. In addition, the Philippine CAEV isolate clustered in group B with the prototype caprine lentivirus. Based on amino acid sequence alignments, it is possible that the Philippine CAEV isolate is a new strain of CAEV, but it is also possible that it was already present in the country even before the start of goat importation. Molecular characterization of the CAEV gag gene is important for the development of a detection kit specific for the local strain of CAEV and the establishment of small ruminant lentivirus eradication programs in the Philippines. This study is the first report to describe the molecular characteristics of CAEV circulating in the Philippines.

Genetic characterization of small ruminant lentiviruses circulating in naturally infected sheep and goats in Ontario, Canada

Maedi-visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) are related members of a group of small ruminant lentiviruses (SRLVs) that infect sheep and goats. SRLVs are endemic in many countries, including Canada. However, very little is known about the genetic characteristics of Canadian SRLVs, particularly in the province of Ontario. Given the importance of surveillance and eradication programs for the control of SRLVs, it is imperative that the diagnostic tests used to identify infected animals are sensitive to local strains of SRLVs. The aim of this work was to characterize SRLV strains circulating in Ontario and to evaluate the variability of the immunodominant regions of the Gag protein. In this study, the nearly complete gag sequence of 164 SRLVs, from 130 naturally infected sheep and 32 naturally infected goats from Ontario, was sequenced. Animals belonged to distantly located single and mixed species (sheep and goats) farms. Ovine lentiviruses from the same farm tended to cluster more closely together than did caprine lentiviruses from the same farm. Sequence analysis revealed a higher degree of heterogeneity among the caprine lentivirus sequences with an average inter-farm pairwise DNA distance of 10% and only 5% in the ovine lentivirus group. Interestingly, amplification of SRLVs from ELISA positive sheep was successful in 81% of cases, whereas amplification of SRLV proviral DNA was only possible in 55% of the ELISA positive goat samples; suggesting that a significant portion of caprine lentiviruses circulating in Ontario possess heterogeneity at the primer binding sites used in this study. Sequences of sheep and goat SRLVs from Ontario were assembled into phylogenetic trees with other known SRLVs and were found to belong to sequence groups A2 and B1, respectively, as defined by Shah et al. (2004a). A novel caprine lentivirus with a pairwise genetic difference of 15.6-25.4% relative to other group B subtypes was identified. Thus we suggest the designation of a novel subtype, B4, within the caprine lentivirus-like cluster. Lastly, we demonstrate evidence of recombination between ovine lentiviruses. These results emphasize the broad genetic diversity of SRLV strains circulating in the province of Ontario and show that the gag region is suitable for phylogenetic studies and may be applied to monitor SRLV eradication programs.

Challenges of the Caprine Lentivirus control programme in South Tyrol, Italy

Abstract Objective of this paper is to describe the challenges associated with the implementation of the control programme of Caprine arthritis encephalitis virus infections in goats in South Tyrol, Italy. From 2007 to 2010, a total of 72,714 goats older than 6 months were serologically tested by means of an ELISA for the presence of Caprine arthritis encephalitis virus antibodies. Seropositive animals were culled. In total, 2576 goats were found to be positive in 2007, 657 goats in 2008, 329 goats in 2009 and 196 goats in 2010. Prevalence of seropositive animals decreased from 14% in 2007 to 1% in 2010. Prevalence of herds with seropositive animals decreased from 32% in 2007 to 6% in 2010. The programme did not disturb the future of the local breed ‘Passeirer Mountain Goat’, although the quality of the breed was considered to have decreased, as the highest rates of infection were recorded in herds with high pedigree goats. Price of animals for slaughter decreased by 50%, due to the surplus of available animals. Trading activities had nearly stopped, as only few herds were fulfilling the requirements of the programme regarding movements of animals to markets. All possible results of the serological test should be explained to farmers, in order to maintain their confidence in the programme and their cooperation.

Small ruminant lentivirus genotype E is widespread in Sarda goat

The highly divergent SRLV genotype E has recently been characterized in Italy as a low pathogenic caprine lentivirus in the Roccaverano breed. The availability of a genotype specific diagnostic test based on a comparative assay, using a combination of genotype specific recombinant antigens allows a wide serosurvey in other goat populations. The island of Sardinia still has the highest small ruminant population of any Italian region and crossbreeding has been limited to goats, mainly with the Maltese breed. A serological survey was carried out on sheep flocks and goat herds, using individual sera as well as a bulk milk-adapted procedure. Genotype E was identified in more than 50% of goat herds and none of the sheep flocks thus supporting the idea that this genotype is specifically associated with the goat species. The full-length proviral sequence of a Sardinian isolate revealed and confirmed the deletion of dUTPase subunit and the absence of both vpr gene and the 71bp repeat of the LTR. Genetic similarity of this isolate with the prototype strain Roccaverano was not more than 84%, supporting the designation of two subtypes within genotype E. Nevertheless, in vitro properties of the Sardinian strain were different from those of the Roccaverano strain in terms of ability to infect synovial membrane and produce syncitia. Remarkable differences in the HV1 and HV2 of the env gene were recorded, with the Sardinian isolate displaying sequence motif more similar to arthritic strains. Data presented suggest diffusion of genotype E is wider than previously thought.

Genome Analysis of Small-Ruminant Lentivirus Genotype E: a Caprine Lentivirus with Natural Deletions of the dUTPase Subunit, vpr -Like Accessory Gene, and 70-Base-Pair Repeat of the U3 Region

The nucleotide sequence of the highly divergent small-ruminant lentivirus genotype E has been determined. The full genome consists of 8,418 nucleotides and lacks two large portions corresponding nearly to the entire dUTPase subunit of the pol and vpr-like accessory genes. Moreover, the 70-bp repeat of the U3 region of the long terminal repeat was observed to be deleted. Interestingly, this lentivirus genotype is able to persist in a local breed population, and retrospective analysis revealed its presence in milk samples collected in 1999. gag sequences obtained from a flock coinfected with the B1 and E genotypes revealed that the evolutionary rates of the two viruses were quite similar. Since a reduced viral load and/or disease progression was observed for viruses with artificially deleted dUTPase and vpr-like genes, it is proposed that this viral cluster be designated a low-pathogenicity caprine lentivirus.

Detection of viral genomes of caprine arthritis-encephalitis virus (CAEV) in semen and in genital tract tissues of male goat

The aim of this study was to determine the infectious status of semen and genital tract tissues from male goat naturally infected with the caprine lentivirus. Firstly, polymerase chain reaction (PCR) was used to detect the presence of CAEV proviral-DNA in the circulating mononuclear cells, semen (spermatozoa and non-spermatic cells), and genital tract tissues (testis, epididymis, vas deferens, and vesicular gland) of nine bucks. RT-PCR was used to detect the presence of CAEV viral RNA in seminal plasma. Secondly, in situ hybridization was performed on PCR-positive samples from the head, body, and tail of the epididymis. CAEV proviral-DNA was identified by PCR in the blood cells of 7/9 bucks and in non-spermatic cells of the seminal plasma of 3/9 bucks. No CAEV proviral-DNA was identified in the spermatozoa fraction. The presence of CAEV proviral-DNA in non-spermatic cells and the presence of CAEV in the seminal plasma was significantly higher (p<0.01) in bucks with PCR-positive blood. Two of the three bucks with positive seminal plasma cells presented with at least one PCR-positive genital tract tissue. Proviral-DNA was found in the head (3/9), body (3/9), and tail (2/9) of the epididymis. In situ hybridization confirmed the presence of viral mRNA in at least one of each of these tissues, in the periphery of the epididymal epithelium. This study clearly demonstrates the presence of viral mRNA and proviral-DNA in naturally infected male goat semen and in various tissues of the male genital tract.

Fatores de risco na transmissão do lentivírus caprino pelo sêmen

O objetivo deste trabalho foi avaliar a presença do DNA pró-viral do lentivírus caprino (LVC) em ejaculados de machos infectados naturalmente, e verificar a influência da lavagem do sêmen e da presença de inflamação testicular sobre a carga viral. Foram realizadas oito coletas de sêmen de sete reprodutores soropositivos para o LVC: quatro antes dos animais sofrerem dano testicular e quatro depois. Entre as coletas realizadas na mesma semana, em uma, o ejaculado era lavado, para retirada do plasma seminal, e na outra, não. O DNA pró-viral do LVC foi identificado pela reação em cadeia da polimerase Nested (PCR Nested), e pelo isolamento viral. O vírus foi isolado em 7,1% das amostras. A PCR identificou o DNA pró-viral em 35,7% do total das amostras: 17,9% nas amostras lavadas e 53,6% das amostras de sêmen integrais. O dano ao testículo permite maior fluxo do vírus para o sêmen, pois antes do dano, 21,4% das amostras foram positivas e pós-dano, 50%. A transmissão do LVC pelo sêmen de reprodutores caprinos é potencializada pela presença de inflamações testiculares e pelo fato de o sêmen criopreservado conter o LVC na forma infectante.

Genetic heterogeneity of small ruminant lentiviruses involves immunodominant epitope of capsid antigen and affects sensitivity of single-strain-based immunoassay.

The pol and gag gene fragments of small ruminant lentivirus field isolates collected in the last decade in Italy were amplified, sequenced, and analyzed. Phylogenetic analysis revealed that the majority of ovine isolates form a distinct cluster more similar to caprine lentivirus prototypes than to the visna virus prototype. These findings confirm and extend those reported by Leroux et al. (Arch. Virol., 142:1125-1137, 1997). Moreover, we observed that a variable region of Gag, included in the fragment analyzed, corresponded to one of the three major capsid antigen epitopes, which suggests that the antibody response to this epitope may be type specific. To test this hypothesis, two recombinant peptides, derived from the Icelandic prototype K1514 and this novel genotype, were expressed and used in an enzyme-linked immunosorbent assay to screen a panel of ovine and caprine sera collected from different geographical locations in Italy. Several sera reacted in a type-specific manner, indicating that in a diagnostic setting the combination of at least these two type-specific peptides is necessary to cover a wide range of infections. Additionally, these results support the hypothesis of cross-species transmission based on the phylogenetic analysis described above. This has implications for the control and eradication of small ruminant lentivirus infections.

Characterisation of an Irish caprine lentivirus strain—SRLV phylogeny revisited

Small ruminant lentiviruses (SRLV), i.e. caprine arthritis-encephalitis virus (CAEV) (which infects goats) and maedi-visna virus (MVV) (which infects sheep) are two closely related lentiviruses but the relationship between goat and sheep lentiviruses has not been clearly established. To better understand their genetic relationship, we reinvestigated the phylogeny of SRLV using new sequences from an Irish and a Norwegian strain together with sequences available from databases. The phylogenetic analyses were carried out on the gag, pol and env fragments using four methods: neighbor-joining (NJ), Fitch and Margoliash (Fitch), Fitch and Wagner parsimony (Pars) and maximum likelihood (ML). The tree topologies were consistent whether derived from any of the four methods or any of the gene fragments, but the phylogenetic analyses in the pol and env regions were more informative than in the gag region. The Tamura-Nei model with variable rates across sites (described by a gamma distribution) provides a more accurate description of SRLV evolution than simple methods. The newly described Irish lentivirus strain, which was isolated from a goat, was closely related to the lentivirus that infects sheep: MVV. The novel Norwegian CAEV strain belonged to a cluster specific to the CAEV strains from Norway. Together, both data confirm the previously reported subdivision of the different SRLV strains into six clades. The caprine and ovine lentivirus sequences are interspersed in phylogenetic trees, supporting the existence of cross-species transmission. Nevertheless, the transmission of an ovine lentivirus to a goat could trigger the emergence of some goat-adapted phylums. Our new sequences confirm the complex situation in SRLV phylogeny but more sequences are needed to elucidate more precisely the relationship between SRLV.

Genetic Characterization of Two Phenotypically Distinct North American Ovine Lentiviruses and Their Possible Origin from Caprine Arthritis-Encephalitis Virus

Ovine and caprine lentiviruses are closely related genetically and antigenically although the diseases that these viruses cause in their respective host animals can vary greatly. In sheep, syndromes consist primarily of interstitial pneumonia with rare occurrences of arthritis and encephalitis, whereas in goats, the disease expresses mainly as arthritis in adult animals with rare cases of encephalitis in newborns. Experimentally, viruses from either sheep or goats can infect animals of the reciprocal species and many field strains of ovine lentivirus have biological properties similar to those of caprine viruses. However, a molecular correlation for the phenotypic differences between ovine and caprine lentivirus strains is unknown. To investigate this, we examined genetic characteristics of two phenotypically distinct North American ovine lentiviruses. Nucleotide sequence analysis of the envelope regions from virus strains 85/34 and 84/28 showed that despite significant biological differences, these viruses are closely related to each other and are genotypically more homologous to caprine arthritis-encephalitis virus (CAEV) than to visna virus of sheep. Furthermore, analysis of the nucleotide substitutions in their env regions indicated that when differences between the two ovine viruses and CAEV were found, the changes often resulted in nucleotides homologous with visna virus. These results suggest that the two field strains of ovine lentivirus may have originated from a cross-species infection of sheep by a CAEV-like virus and, evolution of their genomes toward that of ovine lentivirus may be reflective of adaptation of these viruses to the new ovine host.

Replication in goats in vivo of caprine arthritis-encephalitis virus deleted in vif or tat genes: possible use of these deletion mutants as live vaccines.

AIDS Research and Human RetrovirusesVol. 12, No. 5 Replication in Goats in Vivo of Caprine Arthritis–Encephalitis Virus Deleted in vif or tat Genes: Possible Use of These Deletion Mutants as Live VaccinesABDALLAH HARMACHE, PIERRE RUSSO, CHRISTIAN VITU, FRANÇOIS GUIGUEN, JEAN-FRANÇOIS MORNEX, MICHEL PEPIN, ROBERT VIGNE, and MARIE SUZANABDALLAH HARMACHESearch for more papers by this author, PIERRE RUSSOSearch for more papers by this author, CHRISTIAN VITUSearch for more papers by this author, FRANÇOIS GUIGUENSearch for more papers by this author, JEAN-FRANÇOIS MORNEXSearch for more papers by this author, MICHEL PEPINSearch for more papers by this author, ROBERT VIGNESearch for more papers by this author, and MARIE SUZANSearch for more papers by this authorPublished Online:15 Mar 2009https://doi.org/10.1089/aid.1996.12.409AboutSectionsPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail FiguresReferencesRelatedDetailsCited byDetailed analysis of the promoter activity of an attenuated lentivirusJournal of General Virology, Vol. 97, No. 7Characterization of small ruminant lentivirus A4 subtype isolates and assessment of their pathogenic potential in naturally infected goats3 April 2014 | Virology Journal, Vol. 11, No. 1Immunization against Small Ruminant Lentiviruses2 August 2013 | Viruses, Vol. 5, No. 8Small ruminant lentivirus genotype B and E interaction: Evidences on the role of Roccaverano strain on reducing proviral load of the challenging CAEV strainVeterinary Microbiology, Vol. 163, No. 1-2Small ruminant lentiviruses: Immunopathogenesis of visna-maedi and caprine arthritis and encephalitis virusComparative Immunology, Microbiology and Infectious Diseases, Vol. 35, No. 3Immunological parameters in goats experimentally infected with SRLV genotype E, strain RoccaveranoVeterinary Immunology and Immunopathology, Vol. 139, No. 2-4Development of specific diagnostic test for small ruminant lentivirus genotype EVeterinary Microbiology, Vol. 138, No. 3-4Tumultuous Relationship between the Human Immunodeficiency Virus Type 1 Viral Infectivity Factor (Vif) and the Human APOBEC-3G and APOBEC-3F Restriction FactorsMicrobiology and Molecular Biology Reviews, Vol. 73, No. 2Genome Analysis of Small-Ruminant Lentivirus Genotype E: a Caprine Lentivirus with Natural Deletions of the dUTPase Subunit, vpr -Like Accessory Gene, and 70-Base-Pair Repeat of the U3 RegionJournal of Virology, Vol. 83, No. 2Amino-Terminal Region of the Human Immunodeficiency Virus Type 1 Nucleocapsid Is Required for Human APOBEC3G PackagingJournal of Virology, Vol. 78, No. 21Influence of Primate Lentiviral Vif and Proteasome Inhibitors on Human Immunodeficiency Virus Type 1 Virion Packaging of APOBEC3GJournal of Virology, Vol. 78, No. 4Comprehensive Investigation of the Molecular Defect in vif -Deficient Human Immunodeficiency Virus Type 1 VirionsJournal of Virology, Vol. 77, No. 10Virion Incorporation of Human Immunodeficiency Virus Type-1 Vif Is Determined by Intracellular Expression Level and May Not Be Necessary for FunctionVirology, Vol. 248, No. 2Priming with tat -Deleted Caprine Arthritis Encephalitis Virus (CAEV) Proviral DNA or Live Virus Protects Goats from Challenge with Pathogenic CAEVJournal of Virology, Vol. 72, No. 8In vivo functions of the auxiliary genes and regulatory elements of feline immunodeficiency virusVeterinary Microbiology, Vol. 60, No. 2-4Phenotypically Vif- human immunodeficiency virus type 1 is produced by chronically infected restrictive cellsJournal of Virology, Vol. 71, No. 3 Volume 12Issue 5Mar 1996 To cite this article:ABDALLAH HARMACHE, PIERRE RUSSO, CHRISTIAN VITU, FRANÇOIS GUIGUEN, JEAN-FRANÇOIS MORNEX, MICHEL PEPIN, ROBERT VIGNE, and MARIE SUZAN.Replication in Goats in Vivo of Caprine Arthritis–Encephalitis Virus Deleted in vif or tat Genes: Possible Use of These Deletion Mutants as Live Vaccines.AIDS Research and Human Retroviruses.Mar 1996.409-411.http://doi.org/10.1089/aid.1996.12.409Published in Volume: 12 Issue 5: March 15, 2009PDF download