| immortalization of caprine fibroblasts permissive for replication of small ruminant lentiviruses. | to establish immortalized caprine fibroblastic cell lines permissive for replication of small ruminant lentiviruses. | 1997 | 9185961 |
| risk factors for the infection of swiss goat herds with small ruminant lentivirus: a case-control study. | in the mid-1980s, switzerland started a programme to eradicate caprine arthritis-encephalitis - an infectious disease of goats caused by the small ruminant lentivirus (srlv). since 1996, progress towards eradication has slowed down, owing to infections occurring on farms from which the infection had previously been eliminated. to investigate specific risk factors for these new infections and to improve the eradication programme, a case-control study was conducted. cases consisted of farms that h ... | 2005 | 16113168 |
| distribution and heterogeneity of small ruminant lentivirus envelope subtypes in naturally infected french sheep. | small ruminants lentiviruses (srlv) nucleotide sequences spanning the v1v2 variable regions of the env gene were amplified by nested-pcr from 38 blood samples collected from 16 naturally infected sheep flocks in france. for the rapid srlv group determination of field isolates, the pcr-amplified fragments were subjected to a srlv-adapted heteroduplex mobility assay (hma). all viral sequences were clearly assignable to the srlv group b by hma analysis. twenty-seven srlv isolates were selected for ... | 2006 | 16616391 |
| association of cd80 and cd86 expression levels with disease status of visna/maedi virus infected sheep. | in small ruminant lentivirus infections, cellular immune responses are diminished in clinically affected animals. the underlying mechanisms for this are unknown. in this study, we tested the hypothesis that alterations in expression of the co-stimulatory molecules b7-1 and b7-2 are involved in infections with visna/maedi virus (vmv), the prototype lentivirus of sheep. we studied b7 expression levels ex vivo in peripheral blood mononuclear cells (pbmcs), determining b7 rna levels by real time rev ... | 2007 | 18158734 |
| genetic characterization of small ruminant lentivirus in italian mixed flocks: evidence for a novel genotype circulating in a local goat population. | in this study, characterization of the gag gene of small ruminant lentiviruses was carried out in italian mixed flocks. the nearly complete gag gene was amplified and sequenced. within genotype a, subtype a1 and a novel subtype, a8, were found in goats, and another novel subtype, a9, was found in both sheep and goats. subtype b1 was found in both host species and subtype b2 was identified only in sheep. a novel, highly divergent sequence was obtained from goats in two epidemiologically related f ... | 2007 | 18024912 |
| compartmentalization of small ruminant lentivirus between blood and colostrum in infected goats. | the compartmentalization of small ruminant lentivirus (srlv) subtype a (maedi-visna virus) and b (caprine arthritis-encephalitis virus) variants was analyzed in colostrum and peripheral blood mononuclear cells of four naturally infected goats. sequence analysis of dna and rna encompassing the v4-v5 env regions showed a differential distribution of srlv variants between the two compartments. tissue-specific compartmentalization was demonstrated by phylogenetic analysis in three of the four cases. ... | 2007 | 17719071 |
| natural transmission and comparative analysis of small ruminant lentiviruses in the norwegian sheep and goat populations. | serological surveys for small ruminant lentivirus (srlv) infections have revealed seropositive sheep in several mixed herds, where sheep are kept together with seropositive goats. here we have examined the genetic relationships in ltr, pol and env surface unit (su) and the growth patterns in goat (gsm) and sheep (fos) synovial membrane cell cultures of srlv isolates obtained from both mixed and single species herds. phylogenetic analyses of pol and env su revealed that norwegian srlvs derived fr ... | 2007 | 17240470 |
| application of pcr technique in diagnosis of small ruminant lentivirus infection in sheep and goats. | detection of small ruminant lentiviruses (srlvs) in sheep and goats usually relies on serological testing. in this study, we evaluated semi-nested pcr and nested pcr techniques applied as a diagnostic tool for detection of maedi-visna virus (mvv) and caprine arthritis-encephalitis virus (caev) in naturally infected sheep and goats, respectively. the examination of 193 ovine and 85 caprine serum samples by the elisa revealed the presence of specific antibodies in 133 (69%) and 18 (21.2%) animals, ... | 2006 | 17203738 |
| antibody response in sheep experimentally infected with different small ruminant lentivirus genotypes. | two groups of sheep were experimentally infected by intratracheal route with two small ruminant lentivirus (srlv) isolates belonging to different genotypes (it-561 genotype a3 and it-pi1 genotype b2). seroconversion was evaluated using recombinant homologous and heterologous matrix protein/capsid antigen fusion protein. results clearly indicate that seroconversion against homologous antigen was detected well in advance as regards heterologous antigen in both groups, although the advantage of usi ... | 2006 | 16698088 |
| use of serology and polymerase chain reaction for the rapid eradication of small ruminant lentivirus infections from a sheep flock: a case report. | a srlv-free sheep flock incurred infection which led to an srlv infection rate of over 50% of the ewes (34/64) within a 30 months period, indicating that environmental conditions were favourable to transmission. an intensive regimen of sampling at short intervals and testing for srlv antibodies and proviral dna combined with strict management was implemented for the entire flock, lambs and yearlings included. this resulted in eradication of the infection within two testing and culling rounds wit ... | 2010 | 19500811 |
| serological characterization of the new genotype e of small ruminant lentivirus in roccaverano goat flocks. | maedi visna virus (mvv) and caprine arthritis encephalitis virus (caev) are a heterogeneous group of infectious agents affecting sheep and goats. due to their natural cross-species infection they are referred to as small-ruminant lentiviruses (srlv). recently a new genetic cluster, highly divergent from mvv and caev was identified in the north-west part of italy. a panel of genotype e specific antigens was developed and evaluated in flocks infected with b1 and e strains. the results clearly indi ... | 2009 | 19629741 |
| development of a semi-nested pcr using degenerate primers for the generic detection of small ruminant lentivirus proviral dna. | a pcr assay was developed for the reliable detection of small ruminant lentivirus (srlv) proviral dna. the method involved the use of degenerate deoxyinosine-substituted primers and a second semi-nested pcr step that increased the polyvalency and sensitivity of the detection, respectively. primers were designed from the pol gene conserved motifs of 85 srlv isolates and were evaluated using different srlv isolates together with maedi-visna virus (mvv) and caprine arthritis-encephalitis virus (cae ... | 2006 | 16650487 |
| a novel deletion in the ltr region of a greek small ruminant lentivirus may be associated with low pathogenicity. | greek small ruminant lentivirus (srlv) strains remain relatively uncharacterized at the molecular level, despite the fact that lentiviral diseases of small ruminants are known to be widespread in the country. in the present study, we investigated the sequence diversity of the ltr region in greek srlv strains from sheep with and without disease symptoms, since sequence differences within this genomic area have been shown to lead to srlvs with distinct replication rates. the ap-4 and aml (vis) mot ... | 2006 | 16446005 |
| phylogenetic analysis of small-ruminant lentivirus subtype b1 in mixed flocks: evidence for natural transmission from goats to sheep. | small-ruminant lentiviruses (srlv), consisting of the caprine arthritis-encephalitis virus (caev) and the maedi-visna virus (mvv), cause chronic multisystemic infections in goats and sheep. the srlv subtype b1, characterized by the prototypic strain caev-co, has a worldwide distribution and, remarkably, has been isolated exclusively from goats, suggesting potential host specificity. to test this hypothesis, srlv pol sequences were obtained by pcr amplification from blood samples of seropositive ... | 2005 | 16005486 |
| first partial characterisation of small ruminant lentiviruses from greece. | small ruminant lentivirus (srlv) infections are widespread in greece, but srlvs have never been isolated and characterized. in this study, we present the sequence of a 574-nucleotide (191-amino acid) region of the gag gene of srlv strains from four sheep and one goat from a single geographic area of greece. all five sequences appeared to be closely related at both nucleotide (2.1-14.2% variation) and deduced amino acid (1.6-4.2% variation) level. greek srlv strains were closer to ovine prototypi ... | 2005 | 15964721 |
| establishment and characterization of a goat synovial membrane cell line susceptible to small ruminant lentivirus infection. | primary goat synovial membrane (gsm) cells are widely used to study small ruminant lentiviruses (srlv), i.e. maedi visna virus (mvv) and caprine arthritis-encephalitis virus (caev), but their limited life-span of 15-20 passages in vitro is problematic. here, we report that ectopic expression of the catalytic subunit of human telomerase (htert) was sufficient to immortalize primary gsm cells. cultures of htert-transfected gsm cells have been passaged for 2 years without showing any phenotypic dif ... | 2004 | 15081607 |
| maedi-visna virus and caprine arthritis encephalitis virus genomes encode a vpr-like but no tat protein. | a small open reading frame (orf) in maedi-visna virus (mvv) and caprine arthritis encephalitis virus (caev) was initially named "tat" by analogy with a similarly placed orf in the primate lentiviruses. the encoded "tat" protein was ascribed the function of up regulation of the viral transcription from the long terminal repeat (ltr) promoter, but we have recently reported that mvv and caev tat proteins lack trans-activation function activity under physiological conditions (s. villet, c. faure, b. ... | 2003 | 12915575 |
| diagnostic assays used to control small ruminant lentiviruses. | the serologic diagnostic tests, such as the agar gel immunodiffusion assay and various types of enzyme-linked immunosorbent assays (elisas), have contributed to the reduction of small ruminant lentivirus (srlv) infections worldwide. because there are no treatments or efficacious vaccines, the serologic diagnostic tests have supported most of the eradication efforts by testing and removal or separation of adult animals that generate antibodies to srlvs. with the advent of molecular diagnostics, s ... | 2010 | 21088167 |
| in vitro properties of small ruminant lentivirus genotype e. | small ruminant lentivirus genotype e lacks the dutpase subunit and vpr-like gene. two strains (roccaverano and seui) with identical genetic organization have been described, with the env hv1-hv2 domains being the most divergent. although dutpase and vpr-like deletions have been involved in the rt fidelity in non dividing cells, both strains were able to replicate efficiently in blood derived macrophages (bdm), while virus production of e1 subtype was reduced or abrogated in replicating fibroblas ... | 2010 | 21094509 |
| 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 fr ... | 2002 | 12093681 |
| rapid evolution of two discrete regions of the caprine arthritis-encephalitis virus envelope surface glycoprotein during persistent infection. | five major regions of sequence diversity between strains (v1-v5) have been described in the caprine arthritis-encephalitis lentivirus (caev) envelope surface unit glycoprotein (su). to determine which of these variable regions is important in persistent infection in vivo, we evaluated su sequence diversity in five neutralization variants from two goats and proviral dna from five additional goats infected with caev-63 for up to 7 years. overall amino acid sequence divergence in the su encoded by ... | 2002 | 11900835 |
| elimination of small ruminant lentivirus infection from sheep flocks and goat herds aided by health schemes in great britain. | over a period of 11 years, 33 sheep or goat holdings lost their maedi-visna or caprine arthritis-encephalitis accredited status (mean 2.8 per year [0.09 per cent] of the accredited holdings in great britain). of these, 22 sheep flocks and two goat herds eradicated the infection and regained their accredited status. in addition, 10 sheep flocks and two goat herds managed to eradicate infection, having joined the scheme with infected animals. in flocks and herds with a high initial prevalence of i ... | 2010 | 21257509 |
| host range of small-ruminant lentivirus cytopathic variants determined with a selectable caprine arthritis- encephalitis virus pseudotype system. | the small-ruminant lentiviruses ovine maedi-visna virus (mvv) and caprine arthritis-encephalitis virus (caev) cause encephalitis, progressive pneumonia, arthritis, and mastitis in sheep and goats. icelandic mvv strains, which are lytic in tissue culture, have a wide species distribution of functional receptors, which includes human cells. in contrast, functional receptors for the nonlytic caev co are absent from human cells. to determine if the wide species distribution of functional receptors i ... | 2001 | 11462010 |
| conservation of human immunodeficiency virus type 1 gp120 inner-domain sequences in lentivirus and type a and b retrovirus envelope surface glycoproteins. | we recently described a sequence similarity between the small ruminant lentivirus surface unit glycoprotein (su) gp135 and the second conserved region (c2) of the primate lentivirus gp120 which indicates a structural similarity between gp135 and the inner proximal domain of the human immunodeficiency virus type 1 gp120 (i. hötzel and w. p. cheevers, virus res. 69:47-54, 2000). here we found that the seven-amino-acid sequence of the gp120 strand beta 25 in the c5 region, which is also part of the ... | 2001 | 11160703 |
| a new sensitive serological assay for detection of lentivirus infections in small ruminants. | lentivirus infections in small ruminants represent an economic problem affecting several european countries with important sheep-breeding industries. programs for control and eradication of these infections are being initiated and require reliable screening assays. this communication describes the construction and evaluation of a new serological screening enzyme-linked immunosorbent assay (elisa) for the detection of antibodies to maedi-visna virus (mvv) in sheep and to caprine arthritis encepha ... | 1999 | 10473527 |
| goat milk epithelial cells are highly permissive to caev infection in vitro. | the main route of small ruminant lentivirus dissemination is the ingestion of infected cells present in colostrum and milk from infected animals. however, whether only macrophages or other cell subtypes are involved in this transmission is unknown. we derived epithelial cell cultures, 100% cytokeratin positive, from milk of naturally infected and noninfected goats. one such culture, derived from a naturally infected goat, constitutively produced a high titer of virus in the absence of any cytopa ... | 1999 | 10364490 |
| small ruminant lentivirus genotype b and e interaction: evidences on the role of roccaverano strain on reducing proviral load of the challenging caev strain. | live attenuated vaccines provide the most consistent protective immunity in experimental models of lentivirus infections. in this study we tested the hypothesis that animals infected with a naturally attenuated small ruminant lentivirus field strain of genotype e may control a challenge infection with a virulent strain of the caprine arthritis encephalitis virus (caev-co). within genotype e, roccaverano strain has been described as attenuated since decreased arthritic pathological indexes were r ... | 2012 | 23290119 |
| seroreactivity of peruvian sheep and goats to small ruminant lentivirus-ovine progressive pneumonia virus. | sera from 3,369 sheep and 1,394 goats in peru were examined by agar-gel immunodiffusion for antibodies to ovine progressive pneumonia virus (oppv). the point prevalence rates for antibodies to oppv in sheep were 1.7% to 40.6% (mean, 19.02%) in the 7 flocks studied, whereas for goats, the point prevalence rates for antibodies that cross-reacted with oppv in 12 herds were 0.0% to 45.1%. for sheep, a direct association between increasing age and increasing seroreactivity to oppv was established, an ... | 1987 | 3105369 |
| [diffuse interstitial pneumopathies caused by lentivirus (hiv-1) in humans and animals]. | lentiviruses belong to the retroviruses family (ie rna viruses with reverse transcriptase activity); they induce inflammatory and/or degenerative slowly progressive diseases, affecting various organs. some lentiviruses preferentially infect lymphocytes (hiv-1 and hiv-2, siv and fiv) and are associated with infectious and tumoral disorders. most lentiviruses induce a pulmonary disease, typically diffuse interstitial pneumonia. the visna/maedi-virus of sheep infects monocyte macrophage cells and t ... | 1990 | 1980153 |
| impact of natural sheep-goat transmission on detection and control of small ruminant lentivirus group c infections. | dissemination of small ruminant lentivirus (srlv) infections in norway is affected by the different control strategies used for maedi-visna virus (mvv) infections in sheep and caprine arthritis-encephalitis virus (caev) infections in goats. here we investigated srlv phylogenetic group variants in sheep. caev-like isolates, belonging to phylogenetic group c, were found among both seropositive sheep and goats in mixed flocks, in which sheep and goats are kept together. intra-herd clustering confir ... | 2009 | 18986775 |
| small-ruminant lentivirus enhances prpsc accumulation in cultured sheep microglial cells. | sheep scrapie is the prototypical transmissible spongiform encephalopathy (prion disease), which has a fundamental pathogenesis involving conversion of normal cellular prion protein (prp(c) [c superscript stands for cellular]) to disease-associated prion protein (prp(sc) [sc superscript stands for sheep scrapie]). sheep microglial cell cultures, derived from a prnp 136vv/171qq near-term fetal brain, were developed to study sheep scrapie in the natural host and to investigate potential cofactors ... | 2008 | 18684809 |
| characterization of an immunodominant epitope of small ruminant lentivirus (srlv) nucleoprotein. | to extend and complete the epitope mapping of gag-encoded structural proteins, the immunodiagnostic potential of nucleoprotein (np) of two different small ruminant lentivirus (srlv) genotypes were antigenically characterized. respective recombinant counterparts were generated and used in an enzyme-linked immunosorbent assay (elisa) format to test a panel of sera from infected flocks. results clearly indicate that a single linear epitope located within the c-terminal is partially cross-reactive a ... | 2008 | 18584880 |
| seroprevalence, clinical incidence, and molecular and epidemiological characterisation of small ruminant lentivirus in the indigenous passirian goat in northern italy. | eight dairy flocks, comprising a total of 323 indigenous passirian goats from northern italy, were examined to determine the seroprevalence and clinical incidence of small ruminant lentivirus (srlv) infections and to identify the srlv subtypes. the seroprevalence was 81.5% (55-95%). the clinical incidence was 2.5% (0-8.3%) and was apparently low due to the practice of culling clinically affected animals. phylogenetic analysis of eight pcr fragments (one sample from each flock) revealed that all ... | 2008 | 18584116 |
| small ruminant lentivirus proviral sequences from wild ibexes in contact with domestic goats. | small ruminant lentiviruses (srlv) are widespread amongst domesticated goats and sheep worldwide, but have not been clearly identified in wild small ruminants, where they might constitute an animal health risk through contamination from local domesticates. srlv proviruses from three ibexes from the french alps are described and sequences from their gag gene and long terminal repeats (ltrs) were compared with sequences from local goats and goat/ibex hybrids. the ibex and hybrid proviruses formed ... | 2008 | 18474564 |
| experimental infection of sheep with visna/maedi virus via the conjunctival space. | experiments were performed to determine whether visna/maedi virus (vmv), a small ruminant lentivirus (srlv), could infect sheep via ocular tissues. the ev1 strain of vmv was administered into the conjunctival space of uninfected sheep, and the animals monitored for the presence of provirus dna and anti-vmv antibodies in blood. the results showed that provirus dna appeared in peripheral blood mononuclear cells of all animals within a few weeks of receiving either 10(6) tcid50 or 10(3) tcid50 of v ... | 2008 | 18474547 |
| 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 ... | 2009 | 18987157 |
| small ruminant lentivirus tat protein induces apoptosis in caprine cells in vitro by the intrinsic pathway. | the small ruminant lentiviruses, caprine arthritis-encephalitis virus (caev) and maedi visna virus (mvv) naturally cause inflammatory disease in goats and sheep, provoking chronic lesions in several different organs. we have previously demonstrated that in vitro infection of caprine cells by caev induces apoptosis through the intrinsic pathway (rea-boutrois, a., pontini, g., greenland, t., mehlen, p., chebloune, y., verdier, g. and legras-lachuer, c. 2008). in the present study, we used tat dele ... | 2009 | 19007964 |
| improvements in the detection of small ruminant lentivirus infection in the blood of sheep by pcr. | the polymerase chain reaction on blood samples has been considered a complement to serological methods for the detection of small ruminant lentiviruses (srlv) infections in sheep and goats. this is a report on the results of a study to evaluate the use of the same blood sample for the detection of infected animals by elisa and pcr. a comparison between the results obtained by applying pcrs targeting ltr and gag sequences on blood clot, serum and peripheral blood leucocytes was made. in addition ... | 2009 | 19095008 |
| development of specific diagnostic test for small ruminant lentivirus genotype e. | small ruminant lentivirus (srlv) belonging to the highly divergent genotype e has recently been identified in the italian goat breed roccaverano. in this report we have developed a specific serological test based on recombinant matrix/capsid antigen fusion protein. performance has been evaluated and compared with a similar test based on genotype b antigen. herds under study were selected according to the infectious status characterized by blood pcr and sequencing. results clearly showed that b a ... | 2009 | 19406590 |
| antibody-based diagnosis of small ruminant lentivirus infection in seminal fluid. | antibody-based diagnosis of small ruminant lentiviruses (srlvs) has been efficiently achieved using serum and milk, but not semen, for which polymerase chain reaction (pcr) has been proposed as a confirmatory technique. this work, involving 296 ovine (ovis aries) and caprine (capra hircus) semen donors, investigates whether seminal fluid (sf) can be reliably used in antibody-based srlv diagnosis. first, a gold standard was established to assess the infection status and determine the sensitivity ... | 2009 | 19729193 |
| 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 mal ... | 2010 | 20060658 |
| an insight into a combination of elisa strategies to diagnose small ruminant lentivirus infections. | a single broadly reactive standard elisa is commonly applied to control small ruminant lentivirus (srlv) spread, but type specific elisa strategies are gaining interest in areas with highly prevalent and heterogeneous srlv infections. short (15-residue) synthetic peptides (n=60) were designed in this study using deduced amino acid sequence profiles of srlv circulating in sheep from north central spain and srlv described previously. the corresponding elisas and two standard elisas were employed t ... | 2013 | 23375019 |
| virological and phylogenetic characterization of attenuated small ruminant lentivirus isolates eluding efficient serological detection. | three field isolates of small ruminant lentiviruses (srlvs) were derived from a mixed flock of goats and sheep certified for many years as free of caprine arthritis encephalitis virus (caev). the phylogenetic analysis of pol sequences permitted to classify these isolates as a4 subtype. none of the animals showed clinical signs of srlv infection, confirming previous observations which had suggested that this particular subtype is highly attenuated, at least for goats. a quantitative real time pcr ... | 2013 | 23206411 |
| ltr promoter activity of srlv genotype e, strain roccaverano. | the highly divergent, small ruminant lentivirus (srlv) genotype e roccaverano strain has a full genome consisting of 8,418 nucleotides, which lack the entire dutpase subunit of the pol gene, the vpr-like accessory gene, and the 71-bp repeat of the u3 region within the long terminal repeat (ltr). these deletions affect in reverse transcriptase fidelity in non-dividing cells (dutpase and vpr-like) and in the regulation of viral replication. surprisingly, this srlv strain was able to replicate effi ... | 2010 | 20480232 |
| use of small ruminant lentivirus-infected rams for artificial insemination. | the presence of proviral dna, mrna transcripts and/or viral proteins in small ruminant lentiviral infections may be intermittent. the aim of this study was to identify methods of avoiding small ruminant lentivirus (srlv) transmission to ewes when using infected rams in artificial insemination (ai). semen from rams, seropositive and pcr-positive in blood but consistently negative for both proviral dna and viral protein expression in semen, was used to artificially inseminate 19 ewes. follow-up in ... | 2010 | 20692857 |
| multinucleated giant cells with an osteoclast phenotype derived from caprine peripheral blood mononuclear cells. | formation of multinucleated giant cells (mgcs) by macrophage fusion is a typical cytopathic effect of lentiviral replication in caprine monocytes and mgc formation from cultured caprine peripheral blood mononuclear cells (pbmcs) has been considered to be diagnostic for small ruminant lentivirus (srlv) infection. in this study, formation of mgcs was observed after 7-14days when pbmcs were cultured from healthy goats free from srlv infection. these mgcs expressed tartrate-resistant acid phosphatas ... | 2010 | 20822938 |
| recombinant small ruminant lentivirus subtype b1 in goats and sheep of imported breeds in mexico. | nucleotide sequences of small ruminant lentiviruses (srlvs) were determined in sheep and goats, including progeny of imported animals, on a farm in mexico. on the basis of gag-pol, pol, env and ltr sequences, srlvs were assigned to the b1 subgroup, which comprises caprine arthritis-encephalitis virus (caev)-like prototype sequences mainly from goats. in comparison with caev-like env sequences of american and french origin, two putative recombination events were identified within the v3-v4 and v4 ... | 2010 | 20932787 |
| immunological parameters in goats experimentally infected with srlv genotype e, strain roccaverano. | genotype e of small ruminant lentivirus has been recently described in goats from different breeds in italy. genotype e infection may differ from known genotypes since deletions of dutpase and vpr proteins have been confirmed in different independent areas and goat breed, and play a key role on virus replication and pathogenesis. in particular, genotype e roccaverano strain has been described as low pathogenic since does not lead to clinical symptoms in goats. in contrast, classical caev infecte ... | 2010 | 21122927 |
| interference of vaccination against bluetongue virus serotypes 1 and 8 with serological diagnosis of small-ruminant lentivirus infection. | the effects of the recent vaccinations against bluetongue virus serotype 1 (btv-1) and btv-8 in europe on the reliability of enzyme-linked immunosorbent assays (elisas) currently used for diagnosis of small-ruminant lentivirus (srlv) infection were examined. primary vaccination against btv-8 in goats induced an increase in reactivity that did not exceed 3 months in a whole-virus indirect elisa and a competitive elisa based on the gp135 glycoprotein. subsequent btv-1/8 vaccination extended the ti ... | 2011 | 21228143 |
| characterization of new small ruminant lentivirus subtype b3 suggests animal trade within the mediterranean basin. | small ruminant lentiviruses (srlv) represent a group of viruses infecting sheep and goats worldwide. despite the high heterogeneity of genotype a strains which cluster into as many as 10 subtypes, the genotype b was believed to be less complex and has so far been subdivided into only 2 subtypes. here we describe two novel full-length proviral sequences isolated from sarda sheep in two italian regions. genome sequence as well as the main linear epitopes clearly grouped this cluster into b genotyp ... | 2011 | 21562119 |
| visna/maedi virus genetic characterization and serological diagnosis of infection in sheep from a neurological outbreak. | an extensive outbreak characterized by the appearance of neurological symptoms in small ruminant lentivirus (srlv) infected sheep has been identified in spain, but the genetic characteristics of the strain involved and differential diagnostic tools for this outbreak remain unexplored. in this work, 23 visna-affected naturally infected animals from the outbreak, 11 arthritic animals (both groups presenting anti-visna/maedi virus serum antibodies), and 100 seronegative animals were used. eight of ... | 2011 | 21940116 |
| genetic subgroup of small ruminant lentiviruses that infects sheep homozygous for tmem154 frameshift deletion mutation a4δ53. | small ruminant lentivirus (srlv) infections of sheep are influenced by genetics on both the host and pathogen sides. genetic variation in the ovine transmembrane 154 (tmem154) gene associates with infection susceptibility, and distinct srlv genetic subgroups infect sheep in association with their tmem154 diplotypes. in this study, a novel srlv subgroup was identified that naturally infected sheep with various tmem154 diplotypes, including those homozygous for a rare frameshift mutation (a4 delta ... | 2015 | 25756342 |
| Genetic and antigenic characterization of small ruminant lentiviruses circulating in Poland. | Small ruminant lentivirus (SRLV) infections are widespread in Poland, but the genetic features of sheep viruses are still lacking and limited to partial gag sequences for goat viruses. In this study, segments from the gag and env genes of Polish SRLV strains screened by heteroduplex mobility assay were subjected to genetic analyses. Subtype A1 was found in both sheep and goats, while subtypes B1 and B2 were found in goats and sheep, respectively. In addition, two novel subtypes (named A12 and A1 ... | 2011 | 22155513 |
| Phylogenetic analysis of small ruminant lentivirus (SRLV) in Italian flocks reveals the existence of novel genetic subtypes. | In order to investigate the genetic heterogeneity of small ruminant lentivirus (SRLV) isolates in Italy, 55 clinical samples collected between 1998 and 2010 were analysed. The phylogenetic study was based on analysis of gag-pol sequences. Our findings revealed that the SRLVs belonged to the subtype A9 (n = 3, sheep), B1 (n = 5, goat), B2 (n = 3, sheep) and E2 (n = 5, goat). Interestingly, 39 isolates from both sheep and goat, significantly differed from all the other SRLVs previously described a ... | 2011 | 21858464 |
| post-entry blockade of small ruminant lentiviruses by wild ruminants. | small ruminant lentivirus (srlv) infection causes losses in the small ruminant industry due to reduced animal production and increased replacement rates. infection of wild ruminants in close contact with infected domestic animals has been proposed to play a role in srlv epidemiology, but studies are limited and mostly involve hybrids between wild and domestic animals. in this study, srlv seropositive red deer, roe deer and mouflon were detected through modified elisa tests, but virus was not suc ... | 2016 | 26738942 |
| mutations in ovis aries tmem154 are associated with lower small ruminant lentivirus proviral concentration in one sheep flock. | small ruminant lentivirus (srlv), also called ovine progressive pneumonia virus or maedi-visna, is present in 24% of us sheep. like human immunodeficiency virus, srlv is a macrophage-tropic lentivirus that causes lifelong infection. the production impacts from srlv are due to a range of disease symptoms, including pneumonia, arthritis, mastitis, body condition wasting and encephalitis. there is no cure and no effective vaccine for preventing srlv infection. however, breed differences in prevalen ... | 2014 | 24934128 |
| a census to determine the prevalence and risk factors for caprine arthritis-encephalitis virus and visna/maedi virus in the swiss goat population. | in switzerland, viruses belonging to two different phylogenetic groups of small ruminant lentiviruses (srlv) are currently circulating: the caprine arthritis-encephalitis virus (caev) and visna/maedi virus (vmv). in the past two decades, a mandatory national control program has led to a very low prevalence of seropositivity, while completely eliminating cae as a clinical manifestation. however, in order to reduce the high costs and effort associated with this program, adjustments based on the mo ... | 2017 | 28107881 |
| low proviral small ruminant lentivirus load as biomarker of natural restriction in goats. | small ruminant lentiviruses (srlv) globally affect welfare and production of sheep and goats and are mainly controlled through elimination of infected animals, independently of the viral kinetics within the single animal. control programs are based on highly sensitive serological tests, however the existence of low antibody responders leads to the permanent presence of seronegative infected animals in the flock, thus perpetuating the infection. on the other hand, long-term non-progressors show a ... | 2016 | 27527777 |
| small ruminant lentiviral vif proteins commonly utilize cyclophilin a, an evolutionarily and structurally conserved protein, to degrade ovine and caprine apobec3 proteins. | mammals have co-evolved with retroviruses, including lentiviruses, over a long period. evidence supporting this contention is that viral infectivity factor (vif) encoded by lentiviruses antagonizes the anti-viral action of cellular apolipoprotein b mrna editing enzyme catalytic polypeptide-like 3 (apobec3) of the host. to orchestrate e3 ubiquitin ligase complex for apobec3 degradation, vifs utilize mammalian proteins such as core-binding factor beta (cbfb; for primate lentiviruses) or cyclophili ... | 2016 | 27193350 |
| detailed analysis of the promoter activity of an attenuated lentivirus. | in spite of an eradication campaign that eliminated clinical cases of caprine arthritis encephalitis virus-induced arthritis in the swiss goat population, seroconversions are still observed. in the affected flocks, viruses belonging mainly to the small ruminant lentivirus a4 subtype are regularly isolated. these viruses are considered attenuated, except in the mammary gland, where high viral loads and histopathological lesions have been observed. we previously characterized and sequenced such fi ... | 2016 | 27114068 |
| study of compartmentalization in the visna clinical form of small ruminant lentivirus infection in sheep. | a central nervous system (cns) disease outbreak caused by small ruminant lentiviruses (srlv) has triggered interest in spain due to the rapid onset of clinical signs and relevant production losses. in a previous study on this outbreak, the role of ltr in tropism was unclear and env encoded sequences, likely involved in tropism, were not investigated. this study aimed to analyze heterogeneity of srlv env regions--tm amino terminal and su v4, c4 and v5 segments--in order to assess virus compartmen ... | 2012 | 22281181 |
| 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 g ... | 2015 | 26413072 |
| 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 clu ... | 2015 | 25655265 |
| the concentration of copper, zinc, manganese and selenium in the serum and liver of goats with caprine arthritis-encephalitis. | concentrations of four trace elements, copper (cu), zinc (zn), manganese (mn) and seleni- um (se), have thus far proven to be affected by lentiviral infections in people and rhesus monkeys. as small ruminant lentivirus (srlv) infection is responsible for one of the most important goat diseases, caprine arthritis-encephalitis (cae), we evaluated serum and liver concentrations of cu, zn, mn, se in goats severely affected by symptomatic cae and compared them with litera- ture reference intervals. s ... | 2018 | 30605285 |
| identification and characterization of an emerging small ruminant lentivirus circulating recombinant form (crf). | the molecular epidemiology of small ruminant lentiviruses (srlvs) is constantly changing due to animal movements, cross species transmission and because of their rapid evolutionary rate. this study reports a comprehensive genetic and phylogenetic analysis based on consensus gag and pol sequences covering 3kb of the srlv genome from small ruminants in québec, canada. a group of strains obtained from goats originating from different flocks, segregated in a unique clade distinct from currently know ... | 2015 | 25462356 |
| characterization of small ruminant lentivirus a4 subtype isolates and assessment of their pathogenic potential in naturally infected goats. | small ruminant lentiviruses escaping efficient serological detection are still circulating in swiss goats in spite of a long eradication campaign that essentially eliminated clinical cases of caprine arthritis encephalitis in the country. this strongly suggests that the circulating viruses are avirulent for goats.to test this hypothesis, we isolated circulating viruses from naturally infected animals and tested the in vitro and in vivo characteristics of these field isolates. | 2014 | 24708706 |
| small ruminant lentivirus-induced arthritis: clinicopathologic findings in sheep infected by a highly replicative srlv b2 genotype. | we describe the clinicopathologic features of an arthritis outbreak in sheep induced by small ruminant lentivirus (srlv), linked to the presence of a new srlv isolate phylogenetically assigned to caprine arthritis encephalitis virus-like subgroup b2. thirteen srlv seropositive rasa aragonesa adult ewes were selected from 5 srlv highly infected flocks (mean seroprevalence, 90.7%) for presenting uni- or bilateral chronic arthritis in the carpal joint. a complete study was performed, including symp ... | 2015 | 24476938 |
| distribution of caprine arthritis encephalitis virus provirus, rna, and antigen in the reproductive tract of one naturally and seven experimentally infected bucks. | caprine arthritis encephalitis is a worldwide, multisystemic disease caused by a small ruminant lentivirus. although the main route of transmission is oral, detection of proviral dna of the caprine arthritis encephalitis virus (caev) in caprine semen has been previously described. however, the presence of viral antigens in the male reproductive tract has apparently never been reported. the objective was to study lesions in the buck reproductive system and to detect, in these tissues, the presenc ... | 2013 | 23973050 |
| diversity of caprine arthritis-encephalitis virus promoters isolated from goat milk and passaged in vitro. | transcriptional regulation in retroviruses resides in the u3 region of the proviral long terminal repeat (ltr). transcription binding sites (tbs) in the u3 region of proviral sequences derived from the milk of 17 goats infected with caprine arthritis-encephalitis virus (caev) were analysed by nested pcr and sequencing. u3 sequences shared a high degree of homology (86-99%) and were closely related to isolates previously ascribed to small ruminant lentivirus subtype b1. multiple putative ap-1, ap ... | 2013 | 23183018 |
| toll like receptor 9 (tlr9) polymorphism g520r in sheep is associated with seropositivity for small ruminant lentivirus. | infectious diseases of sheep are of major economic importance causing direct and indirect losses. among the major sheep infectious agents are small ruminant lentivirus, chlamydophila abortus and mycobacterium avium subsp. paratuberculosis infections, mainly due to their worldwide distribution and economic impact that they cause. based on the differential susceptibility to infectious diseases between and within breeds and on the recent findings regarding the putative involvement of tlr9 in diseas ... | 2013 | 23691111 |
| impaired expression of cytokines as a result of viral infections with an emphasis on small ruminant lentivirus infection in goats. | knowing about the genes involved in immunity, and being able to identify the factors influencing their expressions, helps in gaining awareness of the immune processes. the qpcr method is a useful gene expression analysis tool, but studies on immune system genes are still limited, especially on the caprine immune system. caprine arthritis encephalitis, a disease caused by small ruminant lentivirus (srlv), causes economic losses in goat breeding, and there is no therapy against srlv. the results o ... | 2016 | 27399757 |
| small ruminant lentiviruses in sheep. | the objective of this work was to comparatively study the tissue tropism and the associated pathology of 2 autochthonous small ruminant lentivirus (srlv) field strains using an experimental infection in sheep through the bone marrow. fifteen male, srlv-free lambs of the rasa aragonesa breed were inoculated with strain 697 (nervous tissue origin, animals a1-a6), with strain 496 (articular origin, animals b1-b6), or with uninfected culture medium (c1-c3). clinical, serologic, and polymerase chain ... | 2017 | 28113037 |
| goat umbilical cord cells are permissive to small ruminant lentivirus infection in vitro. | small ruminant lentiviruses isolated from peripheral blood leukocytes and target organs can be propagated in vitro in fibroblasts derived from goat synovial membrane cells. these cells are obtained from tissues collected from embryos or fetuses and are necessary for the establishment of the fibroblast primary culture. a new alternative type of host cells, derived from goat umbilical cord, was isolated and characterized phenotypically with its main purpose being to obtain cell monolayers that cou ... | 2017 | 27899238 |
| risk factors associated with small ruminant lentivirus infection in eastern poland sheep flocks. | an analysis of the risk factors for ovine lentivirus infection was performed in sheep flocks located throughout the central-eastern region of poland. here, we report the infection details for 98 flocks with a total of 6470 ewes, 15 sheep breeds. the identification of infected animals and a review of the epidemiological status of each flock were based on an evaluation of serological tests performed on collected blood serum samples. blood for examination was obtained from 2925 ewes of the 98 flock ... | 2016 | 27094139 |
| seropositive bucks and within-herd prevalence of small ruminant lentivirus infection. | caprine arthritis-encephalitis is an economically important disease of goats. it is evident that horizontal transmission through respiratory secretions and milk plays an important part in the disease spread whereas the role of sexual transmission remains questionable. the cross-sectional study was carried out to investigate the relationship between presence of small ruminant lentivirus (srl v)-seropositive bucks and seroprevalence of srl v infection in does in herds. the analysis included 76 goa ... | 2015 | 26648770 |
| prevalence of and risk factors associated with ovine progressive pneumonia in wyoming sheep flocks. | to determine the prevalence of antibodies against small ruminant lentivirus (srlv), the causative agent of ovine progressive pneumonia (opp), and to identify risk factors associated with opp in wyoming sheep flocks. | 2015 | 26421406 |
| small ruminant lentivirus infections and diseases. | small ruminant lentiviruses include viruses with diverse genotypes that frequently cross the species barrier between sheep and goats and that display a great genetic variability. these characteristics stress the need to consider the whole host range and to perform local surveillance of the viruses to opt for optimum diagnostic tests, in order to establish control programmes. in the absence of effective vaccines, a comprehensive knowledge of the epidemiology of these infections is of major import ... | 2015 | 26371852 |
| diagnosing infection with small ruminant lentiviruses of genotypes a and b by combining synthetic peptides in elisa. | the major challenges in diagnosing small ruminant lentivirus (srlv) infection include early detection and genotyping of strains of epidemiological interest. a longitudinal study was carried out in rasa aragonesa sheep experimentally infected with viral strains of genotypes a or b from spanish neurological and arthritic srlv outbreaks, respectively. sera were tested with two commercial elisas, three based on specific peptides and a novel combined peptide elisa. three different pcr assays were use ... | 2015 | 25766510 |
| incidence of infection in 39-month-old ewes with tmem154 diplotypes "1 1," "1 3," and "3 3" after natural exposure to ovine progressive pneumonia virus. | production and well-being of sheep and goats in many countries are harmfully impacted by small ruminant lentiviruses (srlv) that cause incurable, progressive diseases. susceptibility to ovine progressive pneumonia virus (oppv), the north american form of srlv, is influenced by variants of the ovine transmembrane protein 154 gene (tmem154). the experimental objective was to estimate additive and dominance effects of tmem154 haplotypes 1 and 3 on susceptibility of breeding ewes to infection after ... | 2015 | 25568355 |
| influence of small ruminant lentivirus infection on cheese yield in goats. | three-year cohort study was carried out to investigate the influence of small ruminant lentivirus (srlv) infection on cheese yield in goats. for this purpose records of milk yield, milk composition and cheese yield were collected in a dairy goat herd. cheese yield was recorded as the amount of fresh cheese obtained from 1 kg milk. all goats were serologically tested for srlv infection twice a year. the analysis included 247 records in total (71 for seropositive and 176 from seronegative individu ... | 2015 | 25499464 |
| evolution of specific antibodies and proviral dna in milk of small ruminants infected by small ruminant lentivirus. | the diagnosis of small ruminant lentivirus (srlv) is based on clinical signs, pathological lesions and laboratory testing. no standard reference test for the diagnosis of maedi visna has been validated up to the present, and it is puzzling that tests which detect antibodies against the virus and tests which detect the proviral genome may render opposite results. the aim of this study was to evaluate the presence in milk throughout a lactation period of specific antibodies by elisa and of srlv pr ... | 2013 | 24153063 |
| development and validation of taqman probe based real time pcr assays for the specific detection of genotype a and b small ruminant lentivirus strains. | small ruminant lentiviruses (srlv) are members of the retroviridae family and infect goats and sheep worldwide. detection of specific antibodies using agid and elisa is the most commonly used means of diagnosing srlv infection. the most frequent molecular method for detecting the provirus genome is pcr, using peripheral blood leucocytes as target cells. real time pcr has also recently been used. the aim of this study was to develop a real time pcr for detection of srlv in order to improve molecu ... | 2013 | 24004524 |
| small ruminant lentivirus genetic subgroups associate with sheep tmem154 genotypes. | small ruminant lentiviruses (srlvs) are prevalent in north american sheep and a major cause of production losses for the u.s. sheep industry. sheep susceptibility to srlv infection is influenced by genetic variation within the ovine transmembrane 154 gene (tmem154). animals with either of two distinct tmem154 haplotypes that both encode glutamate at position 35 of the protein (e35) are at greater risk of srlv infection than those homozygous with a lysine (k35) haplotype. prior to this study, it ... | 2013 | 23895262 |
| phylogenetic analysis of small ruminant lentiviruses in mixed flocks: multiple evidence of dual infection and natural transmission of types a2 and b1 between sheep and goats. | previous molecular analyses of small ruminant lentivirus (srlv) populations in single species herds in quebec, canada, have revealed a relatively simple structure where goats and sheep appeared exclusively infected with b1 and a2 subtypes respectively. the present work aimed at extending these earlier findings with the analysis of srlvs in mixed flocks. molecular analyses revealed a more complex picture of srlv population structure in mixed herds compared to single species herds. notably, phylog ... | 2013 | 23811153 |
| the risk of small ruminant lentivirus (srlv) transmission with reproductive biotechnologies: state-of-the-art review. | reproductive biotechnologies are essential to improve the gene pool in small ruminants. although embryo transfer (et) and artificial insemination (ai) greatly reduce the risk of pathogen transmission, few studies have been performed to quantify this risk. the aim of this review is to contribute to the elements needed to evaluate the risk of lentivirus transmission in small ruminants (srlv) during et, from embryos produced in vitro or in vivo, and with the use of the semen destined for ai. the pu ... | 2013 | 23131465 |
| mannose receptor may be involved in small ruminant lentivirus pathogenesis. | thirty-one sheep naturally infected with small ruminant lentiviruses (srlv) of known genotype (a or b), and clinically affected with neurological disease, pneumonia or arthritis were used to analyse mannose receptor (mr) expression (transcript levels) and proviral load in virus target tissues (lung, mammary gland, cns and carpal joints). control sheep were srlv-seropositive asymptomatic (n = 3), seronegative (n = 3) or with chronic listeriosis, pseudotuberculosis or parasitic cysts (n = 1 in eac ... | 2012 | 22591485 |
| prevalence of small ruminant lentivirus and mycobacterium avium subsp. paratuberculosis co-infection in ontario dairy sheep and dairy goats. | infection with small ruminant lentiviruses (srlv) causes a variety of chronic inflammatory conditions that limit production. mycobacterium avium subsp. paratuberculosis (map) is also a major production-limiting disease of sheep and goats, which causes severe inflammation of the small intestine. previous studies have indicated that both srlv and map are widespread in small ruminants in ontario. this study estimated the prevalence of srlv and map co-infection. serum samples that were previously te ... | 2017 | 28408784 |
| influence of true within-herd prevalence of small ruminant lentivirus infection in goats on agreement between serological immunoenzymatic tests. | the study was conducted to evaluate influence of the true within-herd prevalence of small ruminant lentivirus (srlv) infection on agreement beyond chance between three different types of commercial serological elisas. blood samples were collected from 865 goats from 12 dairy goat herds. serum samples were tested using three commercial elisa kits: whole-virus indirect elisa (welisa), indirect elisa based on recombined tm and ca antigens (tm/ca-elisa), and competitive-inhibition elisa based on su ... | 2017 | 28716207 |
| seroprevalence of small ruminant lentivirus (srlv) infection in wild cervids in poland. | small ruminant lentiviruses (srlv) are widespread amongst domesticated sheep and goats worldwide. infection of wild ruminants in close contact with affected domesticated small ruminants has been proposed as an actor in srlv epidemiology, but studies are limited. the aim of this study was to estimate the apparent (ap) and estimated prevalence (ep) of exposure to srlv infection in wild ruminants from poland. samples originating from 198 free-living cervids comprising 142 european red deer and 56 r ... | 2020 | 32004826 |
| gene expression profile in peripheral blood nuclear cells of small ruminant lentivirus-seropositive and seronegative dairy goats in their first lactation. | the immune response to a viral antigen causes inflammatory cell infiltration to the tissue, which creates a suitable environment for the replication of the virus in macrophages, and the recruitment of more monocytes to the site of infection, or latently infected monocytes. the aim of the study was to analyze the transcriptomic profile of peripheral blood nuclear cells isolated from srlv-seropositive and srlv-negative goats at the peak of their first lactation. srlv-seropositive goats were probab ... | 2021 | 33810360 |