Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SWINE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

[Analysis of SNPs in exons 2 and 3 of the leptin gene in wild boar, swine and hybrid swine].

Leptin is a 167-amino acid hormone mainly expressed in the fat tissue. It serves as an important regulator of energy uptake and consumption through action on the hypothalamus. Herein single nucleotide polymorphisms (SNPs) were detected in exons 2 and 3 of the Leptin gene in wild boar, swine and half-bred swine by PCR-SSCP. Cloning and sequencing of homozygous fragments revealed the following variations in the coding region: a silent T to C transversion at nucleotide 214; CG to GC at nucleotides 364 and 365, which converts Arg to Ala; a silent G to A transversion at nucleotide 426; a T insertion at nucleotide 451 resulting in frameshift; and a G to T transversion at nucleotide 462.

Amino Acid Substitution↗

Transmissible gastroenteritis (TGE) of swine: effect of age of swine testes cells culture monolayers on plaque assays of TGE virus.

A continuous line of swine testes cell culture monolayers was infected at various ages with both cell culture-adapted transmissible gastroenteritis (TGE) virus and tissue infected with TGE virus. Both produced increasing numbers of plaques as the cell monolayers aged from two to five days. Therefore, allowing the swine testes cell monolayer to age five to six days before inoculation should increase the likelihood of detecting TGE virus by plaque assay.

Animals↗

[Replication of a local strain of swine parvovirus in swine kidney cell cultures].

The kinetics of replication of strain of parvovirus in swine was investigated in the primary cell cultures of swine kidney. The morphologic changes were traced in inoculated cultures by microscopic observation and the replication of the virus in the cells by immune-fluorescent examinations. The quality of the virus in the cell monolayer and in the nutritive medium, in the different periods after the infection, was determined by hemagglutination test. By the immune-fluorescent examinations, the virus was proved still in the first hours, while the first morphologic changes of the monolayer were determined 72 hours after the infection. The nuclear fluorescent appears at the 12-th hour and increases its intensity 24 hours after the infection. At the 72-nd hour and later predominates the cytoplasmatic fluorescent. The cell monolayer produces virus up to the 96-th hour, and the virus titer reaches its maximum 120 hours after the inoculation, which is the most appropriate moment for the yield of virus.

Animals↗

In vitro studies of group E streptococci in swine leukocytes. II. Phagocytic and bactericidal properties of macrophages from immune and nonimmune swine.

Macrophages collected from susceptible swine and grown in nonimmune serum phagocytized and digested group E Streptococci (GES). However, macrophages collected from immune swine and grown in nonimmune serum were capable of much higher rates of phagocytosis and intracellular digestion of the organism. The addition of immune serum to cultures of immune macrophages increased the rate of phagocytosis but not the rate of intracellular digestion of GES by the macrophages. These findings are discussed in relation to mechanisms of cellular immunity.

Animals↗

Transplantation in miniature swine. VIII. Recombination within the major histocompatibility complex of miniature swine.

Offspring of heterozygous parents derived from three herds of miniature swine, each of which is homozygous at the major histocompatibility complex (MHC), were screened for recombination within the MHC. The swine were typed serologically at weaning and later typed by mixed lymphocyte reaction (MLR). Two intra-MHC recombinants were discovered, both of which involved the exchange of D region specificities without apparent dissociation of ABC region specificities, confirming the localization of the SLA-D region outside of the SLA-ABC regions. The first recombinant was the offspring of an SLAc/d (cd) by dd mating and typed serologically as cd but typed by MLR as dd. The second recombinant was the offspring of a cd by cd mating. It typed serologically as cc but stimulated cc in one-way MLR and retained its reactivity to dd, thus suggesting a possible recombination within the D region. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of 3H-leucine-labeled lymphocyte surface antigens demonstrated that corresponding Ia antigens were also exchanged during these recombinant events supporting the hypothesis that genes coding for Ia antigens are identical or closely linked to D region genes encoding the MLR specificities.

Animals↗

Transplantation in miniature swine. IX. Swine histocompatibility antigens: isolation and purification of papain-solubilized SLA antigens.

Histocompatibility antigens have been purified by papain treatment of crude cellular membranes obtained from spleen and mesenteric lymph nodes of individual miniature swine that are homozygous at the major histocompatibility complex. The purification protocol included ultracentrifugation, gel filtration, ion-exchange chromatography, and in some instances preparative isoelectric focusing. This procedure was applied to the preparation of sLA antigens from the 3 haplotypes available in our partially inbred miniature swine herd. The purity of the SLAdd molecules was evidenced by: 1) a single activity peak of approximately 50,000 daltons on gel-permeation chromatography; 2) the antigen elution as a symmetrical peak from ion-exchange resins and from isoelectric focusing columns; 3) the presence of 2 predominant polypeptide chains on SDS-PAGE at apparent m.w. 43,000 and 13,000 daltons; and 4) specific immunoprecipitations by alloantisera and by anti-beta 1 microglobulin antisera. The antigenic activity of SLA products was analyzed by inhibition of complement-mediated cytotoxicity and by removal on anti-beta 2-microglobulin affinity columns. Heavy and light chains were separated by gel-filtration on Sephacryl S-200 in 6 molar guanidine. These SLA products, which have thus been shown to be pure by a variety of criteria, are now readily available for structural analysis and for analysis of biologic activity.

Animals↗

Modulation of splenic macrophages, and swine leukocyte antigen (SLA) and viral antigen expression following African swine fever virus (ASFV) inoculation.

Expression of viral and major histocompatibility complex (MHC) antigens and localization of T cells and macrophages was studied in frozen tissue sections of spleens taken from normal pigs or from pigs inoculated with highly virulent Lisbon 60 (L60), or with moderately virulent Dominican Republic 1978 (DR-II), African swine fever virus (ASFV) isolates. Splenic sections from L60 inoculated pigs exhibited a large decrease in macrophage staining, whereas DR-II infected animals appeared more intensely stained in the macrophage sheath arteries. Class I and class II MHC expression was decreased in spleens from pigs infected with either isolate at 3 day post inoculation (DPI). This was reversed in DR-II inoculated pigs at 4 DPI. Splenic tissue sections from L60 inoculated pigs exhibited only a marginal increase in SLA expression at a later time, 6 DPI. We suggest that the recovery of SLA expression during infection of pigs with ASFV is associated with survival or replacement of macrophages in the spleen leading to an effective immune response against the virus.

African Swine Fever↗

Oral immunisation of swine with a classical swine fever vaccine (Chinese strain) and transmission studies in rabbits and sheep.

Seven experiments including a total of 47 pigs, 11 wild boars, 26 rabbits, 10 hares and 16 sheep were carried out to assess the efficacy, safety and transmission of the Chinese vaccine strain of the classical swine fever virus (CSFV) administrated by the oral route. Within 3 weeks after oral vaccination, a clear seroconversion occurred in the pigs. Six weeks after vaccination, vaccinated pigs were fully protected against a virulent challenge. The C-strain was not isolated from tonsils, spleen, lymph nodes, thymus, saliva, urine and faeces of pigs within 4 days after oral vaccination. In one experiment, susceptible pigs were placed in direct contact with vaccinated pigs. None of these contact-exposed pigs became serologically positive for CSFV antibodies. It is concluded that the C-strain induces protection in pigs when administrated by the oral route and is not shed by vaccinated pigs. Serum anti-CSFV antibodies developed in seven out of eight wild boars vaccinated by the oral route. No vaccine virus was detected in the spleen and tonsils of these animals. The results in wild boar were in accordance with those obtained in domestic pigs. Sheep did not show any clinical signs after oral vaccination while rabbits had moderate hyperthermia and growth retardation. No clinical response to oral immunisation in hares was detected. At the end of the experiment, no sheep had detectable serum antibodies against CSFV, whereas a few vaccinated rabbits and hares became seropositive. None of the contact-exposed rabbits and hares seroconverted. These data indicate that the C-strain is safe for sheep and as expected, moderately or not pathogenic for rabbits and hares. These efficacy and safety studies on oral vaccination with the C-strain under experimental conditions provide essential information for further studies in wild boars under experimental and field conditions, including assays with baits to control a CSF epidemic.

Administration, Oral↗

Isolation of African swine fever virus from ticks of the Ornithodoros moubata complex (Ixodoidea: Argasidae) collected within the African swine fever enzootic area of Malawi.

Ticks of the Ornithodoros moubata complex were collected from domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of African swine fever (ASF) virus. Collections were made in 9 of the 24 districts of Malawi, these being primarily the districts in which O. moubata is most numerous. ASF virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in Mchinji district where ASF outbreaks had recently occurred. Mchinji district is in the centre of a large ASF enzootic area which stretches into other districts of Malawi and also into Zambia and Mozambique. The high titre of virus in some of the ticks demonstrates that O. moubata can act as a virus reservoir and potential vector of disease in the field situation in Malawi.

African Swine Fever↗

Immunofluorescent studies on chronic pneumonia in swine with experimentally induced African swine fever.

Chronic pneumonia experimentally produced in 14 pigs with African swine fever (ASF) virus was studied by immunofluorescene (IF) and histopathologic techniques. Frozen sections prepared from pulmonary tissues of the infected pigs were stained with fluorescein-conjugated antiserums against ASF viral antigen, porcine immunoglobulin G (IgG), procine complement (C), and porcine fibrinogen. The viral antigen(s) was mainly seen in macrophages and cell debris in alveolar walls and lumens. This finding indicates that the virus replicated in the cytoplasm of alveolar macrophages that subsequently degenerated and released the viral antigen. Diffuse immunoglobulin (Ig) deposition was found in necrotic cells and debris. Immunoglobulin also was seen bound to intracytoplasmic inclusion bodies in some degenerating alveolar macrophages. This finding indicates that antibody against ASF viral antigen(s) excluded from blood circulation or produced by local immunocytes (or both) reacted with viral antigen at intramacrophage and extramacrophage levels and resulted in the formation of insoluble antigen-antibody (Ag-Ab) complexes. The participation of C in the immune complex was evident in the early stage of the pneumonia, but was less evident in the subsequent extensive, progressive necrotic processes. Fibrin deposits were visible only in the early necrotic area of alveolar walls and lumens. Possible mechanisms inducing extensive necrosis are discussed.

African Swine Fever↗

[Differential diagnosis of classical swine fever and border disease: seroepidemiological investigation of a pestivirus infection on a mixed sheep and swine farm].

During recent years neutralizing antibodies against Border Disease Virus (BDV) were found repeatedly in German pig herds. Consequently there was a demand for a differential diagnostic system. A permanent sheep cell line and BDV reference strain Moredun were chosen and were applied in a could be used case study. A pestivirus could be isolated from piglets on a mixed farm and was characterised as 'non-Classical Swine Fever' (CSF) by using monoclonal antibodies. Due to a CSF suspicion the pig herd was destroyed immediately. Serum samples of sheep from the same farm were used for further characterisation of the new virus isolate. A neutralization test of the sheep sera was performed against different pestiviruses and the new isolate. Neutralizing antibody titres against the new virus pig isolate were significantly higher than against all other pestiviruses. BDV strain Moredun recognised the antibodies clearly, whereas CSF viral strain Alfort 187 and several isolates of bovine viral diarrhoea virus (BVDV) strains scored the lowest cross reaction.

Animals↗

Extraction of viral DNA from erythrocytes of swine with acute African swine fever.

The preparation of wild-type African swine fever (ASF) virus DNA from small amounts of viremic blood from acutely febrile pigs is outlined. The extracted DNA is viral and not host-cell DNA, because of specific homology with cell culture grown and purified ASF virus and because no DNA bands are obtained with an equal amount of nonviremic pig blood. Thus, in the absence of suitable serologic methods for strain identification, it is now possible to catalogue wild-type isolates by characteristic DNA restriction patterns. The wild-type virus genome contains terminal single-stranded DNA cross-links and has the largest genome size (180 kilobase pairs) reported for the ASF virus. Experimental passage of the virus in contact-infected pigs and buffy coat cultures appears to confirm the stable nature of the ASF genome in the field.

African Swine Fever↗

Replication and plaque formation of swine hemagglutinating encephalomyelitis virus (67N) in swine cell line, SK-K culture.

Swine hemagglutinating encephalomyelitis virus (HEV), 67N strain, adapted to suckling mouse brain, grew readily in a porcine cell line, SK-K cell culture with cytopathic effect (CPE) consisting of syncytium formation and detachment of fused cells and round cells from glass surface. After further passages in SK-K cell monolayers with undiluted culture fluid, CPE developed earlier and became complete within 48 h postinoculation (p.i.). Viral specific antigen was detected in the cytoplasm of the infected SK-K cells by indirect immunofluorescence using rabbit antiserum against the mouse-passaged virus. The SK-K-passaged virus as well as the original mouse-passaged virus formed clear plaques on SK-K cell monolayers under simple overlay medium. The plaque assay system for HEV 67N was established by studying various factors influencing the plaque formation in the SK-K cell cultures. By this system more than 10(6) PFU/0.2 ml of the virus yield was detected in the fluid phase of the infected cultures at 48 h p.i. The SK-K-passaged virus caused fatal infection in 4-week-old mice by intracerebral inoculation, but was inhibited by rabbit antiserum against the mouse-passaged virus. Plaque formation and hemagglutinating activity of the virus were specifically inhibited by antisera against the mouse-passaged and SK-K-passaged 67N virus.

Animals↗

Vaccination with a single dose of a recombinant porcine adenovirus expressing the classical swine fever virus gp55 (E2) gene protects pigs against classical swine fever.

A recombinant porcine adenovirus (rPAV) with the gp55 (E2) gene from the classical swine fever virus (CSFV) 'Weybridge' strain inserted into the right hand end of the PAV serotype 3 (PAV3) genome was constructed. Expression of gp55 was directed by the major late promoter and tri-partite leader sequences located and cloned from PAV3. No compensatory deletions of PAV DNA sequences were made. Vaccination of outbred pigs with a single dose of the recombinant virus (rPAV-gp55) resulted in complete protection from lethal challenge with CSFV. No adverse clinical signs were observed in vaccinated animals following administration of rPAV-gp55 and following challenge, no clinical signs of CSF were observed prior to, or at, post mortem. The insert made into the rPAV increased the genome length to 106.8% of wild type and therefore exceeded the expected maximum insert size for a stable recombinant by almost 2%. Thus rPAV-gp55 contains the largest stable insertion made into a non-deleted Mastadeno virus recombinant so far reported.

Adenoviridae↗

Seroprevalence of Trichinella infection in domestic swine based on the National Animal Health Monitoring System's 1990 and 1995 swine surveys.

Swine sera collected by the US Department of Agriculture's Center for Animal Health Monitoring during 1990 and 1995 was tested for antibodies to Trichinella spiralis using an enzyme immunoassay. From a total of 3048 sera collected from lactating sows in 1990, five sera tested positive for a prevalence of 0.16%. From a total of 7987 sera collected from both finishing pigs and gestating sows in 1995, one serum was positive for a prevalence of 0.013%. Responses to questionnaires administered at the time of serum collection showed that seropositive farms had management variables consistent with known risk factors for exposure to trichinae.

Animal Husbandry↗

Effects of altrenogest and exogenous gonadotropins on ovarian function and embryo recovery in swine leukocyte antigen inbred miniature swine as influenced by cystic endometrial hyperplasia.

Altrenogest (ALT), a synthetic progestogen, and exogenous gonadotropins were administered to the Swine Leukocyte Antigen (SLA) inbred miniature pig that typically has a reduced ovulation rate and small litter size. In Study 1, 15 adult female pigs were either controls (Group I, n = 5), fed 15 mg ALT/day for 14 days (Group II, n = 5), or fed ALT and treated with pregnant mare's serum gonadotropin (1200 IU, i.m.) and human chorionic gonadotropin (500 IU, i.m.) 24 h and 104 h, respectively, after ALT withdrawal (Group III, n = 5). In Study 2, three groups of pigs (I, n = 24; II, n = 11; III, n = 11) were treated similarly to those in Study 1 except that pigs in Study 2 (Groups II and III) were mated. Ovaries of all animals in both studies were examined laparoscopically or by laparotomy 5-8 days after estrus to assess ovarian activity. The uteri of Group II and III animals in Study 2 were flushed with tissue culture medium, which was evaluated for the presence and quality of embryos. No pig demonstrated estrous behavior during ALT administration. Not all animals demonstrated typical estrous behavior after ALT withdrawal. When the data from both studies were combined, 2 of 16 (12.5%) of group II and 6 of 16 (37.5%) of Group III pigs failed to demonstrate standing estrus. Following ALT withdrawal, females in Groups II and III returned to estrus in 5.6 +/- 0.3 and 5.8 +/- 0.3 days, respectively (p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

A nonessential African swine fever virus gene UK is a significant virulence determinant in domestic swine.

Sequence analysis of the right variable genomic region of the pathogenic African swine fever virus (ASFV) isolate E70 revealed a novel gene, UK, that is immediately upstream from the previously described ASFV virulence-associated gene NL-S (L. Zsak, Z. Lu, G. F. Kutish, J. G. Neilan, and D. L. Rock, J. Virol. 70:8865-8871, 1996). UK, transcriptionally oriented toward the right end of the genome, predicts a protein of 96 amino acids with a molecular mass of 10.7 kDa. Searches of genetic databases did not find significant similarity between UK and other known genes. Sequence analysis of the UK genes from several pathogenic ASFVs from Europe, the Caribbean, and Africa demonstrated that this gene was highly conserved among diverse pathogenic isolates, including those from both tick and pig sources. Polyclonal antibodies raised against the UK protein specifically precipitated a 15-kDa protein from ASFV-infected macrophage cell cultures as early as 2 h postinfection. A recombinant UK gene deletion mutant, deltaUK, and its revertant, UK-R, were constructed from the E70 isolate to study gene function. Although deletion of UK did not affect the growth characteristics of the virus in macrophage cell cultures, deltaUK exhibited reduced virulence in infected pigs. While mortality among parental E70- or UK-R-infected animals was 100%, all deltaUK-infected pigs survived infection. Fever responses were comparable in E70-, UK-R-, and deltaUK-infected groups; however, deltaUK-infected animals exhibited significant, 100- to 1,000-fold, reductions in viremia titers. These data indicate that the highly conserved UK gene of ASFV, while being nonessential for growth in macrophages in vitro, is an important viral virulence determinant for domestic pigs.

African Swine Fever Virus↗

Viral wasting syndrome of swine: experimental reproduction of postweaning multisystemic wasting syndrome in gnotobiotic swine by coinfection with porcine circovirus 2 and porcine parvovirus.

One-day-old gnotobiotic piglets were inoculated intranasally with in vitro passaged porcine circovirus 1 (PCV-1), PCV-2, and porcine parvovirus (PPV) alone or in combination (PCV-1/PCV-2, PCV-1/PPV, and PCV-2/PPV). Piglets were evaluated for 1) the development of porcine postweaning multisystemic wasting syndrome (PMWS), 2) distribution of viral antigens by immunochemistry, and 3) viremia and the presence of viral DNA in nasal and ocular secretions and feces. All single agent-infected piglets and piglets infected with PCV-1/PCV-2 or PCV-1/PPV were clinically asymptomatic. They were transiently viremic and seroconverted to homologous virus(es). At termination of the study on postinfection day (PID) 35, microscopic lesions were restricted to focal inflammatory cell infiltrates in livers and myocardia. One piglet given PCV-1/PPV was PPV viremic for 2 weeks after infection and had lymphangiectasia of the spiral and descending colon associated with granulomatous inflammation. All four PCV-2/PPV-inoculated piglets developed PMWS, characterized by sudden onset of depression and anorexia, icterus, and submucosal edema. One piglet became moribund on PID 27, and the remaining three piglets were euthanatized between PID 27 and PID 30 because of severe disease. Lymph nodes were small and the livers were mottled. Disseminated angiocentric granulomatous inflammation was present in all tissues examined except the brain. Multiple lightly basophilic intracytoplasmic inclusion bodies were identified in macrophages and histiocytes. PCV-2 antigen was widely distributed within macrophages; PPV antigen was sparse. Hepatocellular necrosis and bile retention were prominent. PCV-2 DNA was identified in ocular, fecal, and nasal secretions. Terminal sera contained antibodies to PPV (4/4) and PCV-2 (3/ 4). Production of PMWS in gnotobiotic swine appears to require PCV-2 and additional infectious agents such as PPV for full disease expression in gnotobiotic piglets.

Animals↗