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Background: Influenza A Viruses (IAV) are endemic pathogens of significant concern in humans and multiple keystone livestock species. Widespread morbidity in swine herds negatively impacts animal welfare standards and economic performance whilst human IAV pandemics have emerged from pigs on multiple occasions. To combat the rising prevalence of swine IAV there must be effective control strategies available. Main body: The most basic form of IAV control on swine farms is through good animal husbandry practices and high animal welfare standards. To control inter-herd transmission, biosecurity considerations such as quarantining of pigs and implementing robust health and safety systems for workers help to reduce the likelihood of swine IAV becoming endemic. Closely complementing the physical on-farm practices are IAV surveillance programs. Epidemiological data is critical in understanding regional distribution and variation to assist in determining an appropriate response to outbreaks and understanding the nature of historical swine IAV epidemics and zoonoses. Medical intervention in pigs is restricted to vaccination, a measure fraught with the intrinsic difficulties of mounting an immune response against a highly mutable virus. It is the best available tool for controlling IAV in swine but is far from being a perfect solution due to its unreliable efficacy and association with an enhanced respiratory disease. Because IAV generally has low mortality rates there is a reticence in the uptake of vaccination. Novel genetic technologies could be a complementary strategy for IAV control in pigs that confers broad-acting resistance. Transgenic pigs with IAV resistance are useful as models, however the complexity of these reaching the consumer market limits them to research models. More promising are gene-editing approaches to prevent viral exploitation of host proteins and modern vaccine technologies that surpass those currently available. Conclusion: Using the suite of IAV control measures that are available for pigs effectively we can improve the economic productivity of pig farming whilst improving on-farm animal welfare standards and avoid facing the extensive social and financial costs of a pandemic. Fighting 'Flu in pigs will help mitigate the very real threat of a human pandemic emerging, increase security of the global food system and lead to healthier pigs. [ABSTRACT FROM AUTHOR]

Vaccine immunization is now one of the most effective ways to control porcine reproductive and respiratory syndrome virus (PRRSV) infection. Impurity is one of the main factors affecting vaccine safety and efficacy. Here we present a novel innovative PRRSV purification approach based on surface display technology. First, a bifunctional protein PA-GRFT (protein anchor-griffithsin), the crucial factor in the purification process, was successfully produced in Escherichia coli yielding 80 mg/L of broth culture. Then PRRSV purification was performed by incubation of PA-GRFT with PRRSV and gram-positive enhancer matrix (GEM) particles, followed by centrifugation to collect virions loaded onto GEM particles. Our results showed that most of the bulk impurities had been removed, and PA-GRFT could capture PRRSV onto GEM particles. Our lactic acid bacteria-based purification method, which is promising as ease of operation, low cost and easy to scale-up, may represent a candidate method for the large-scale purification of this virus for vaccine production. [ABSTRACT FROM AUTHOR]

The glycoprotein GP3 of the Arterivirus porcine reproductive and respiratory syndrome virus (PRRSV) consists of a cleaved signal peptide, a highly glycosylated domain, a short hydrophobic region and an unglycosylated C-terminal domain. GP3 is supposed to form a complex with GP2 and GP4 in virus particles, but secretion of GP3 from cells has also been reported. We analyzed the membrane topology of GP3 from various PRRSV strains. A fraction of the protein is secreted from transfected cells; GP3 from PRRSV-1 strains to a greater extent than GP3 from PRRSV-2 strains. This secretion behavior is reversed after exchange of the variable C-terminal domain. A fluorescence protease protection assay shows that the C-terminus of GP3, fused to GFP, is resistant against proteolytic digestion in permeabilized cells. Furthermore, glycosylation sites inserted into the C-terminal part of GP3 are used. Both experiments indicate that the C-terminus of GP3 is translocated into the lumen of the endoplasmic reticulum. Deletion of the conserved hydrophobic region greatly enhances secretion of GP3 and fusion of this domain to GFP promotes membrane anchorage. Bioinformatics suggests that the hydrophobic region might form an amphipathic helix. Accordingly, exchanging only a few amino acids in its hydrophilic face prevents and in its hydrophobic face enhances secretion of GP3. Exchanging the latter amino acids in the context of the viral genome did not affect release of virions, but released particles were not infectious. In sum, GP3 exhibits an unusual hairpin-like membrane topology that might explain why a fraction of the protein is secreted. IMPORTANCE The porcine reproductive and respiratory syndrome virus (PRRSV) is the most important pathogen in the pork industry. It causes persistent infections that lead to reduced weight gain of piglets; highly pathogenic strains even kill 90% of an infected pig population. PRRSV cannot be eliminated from pig farms by vaccination due to the large amino acid variability between the existing strains, especially in the glycoproteins. Here we analyzed basic structural features of glycoprotein 3 (GP3) from various PRRSV strains. We show that the protein exhibits an unusual hairpin-like membrane topology; membrane anchoring might occur via an amphipathic helix. This rather weak membrane anchor explains why a fraction of the protein is secreted from cells. Interestingly, PRRSV-1 strains secrete more GP3 than PRRSV-2. We speculate that secreted GP3 might play a role during PRRSV infection of pigs; it might serve as a decoy to distract antibodies away from virus particles. [ABSTRACT FROM AUTHOR]

Background: The intracellular bacterium Lawsonia intracellularis is an important pathogen in modern swine production. The aim of this study was to investigate the effect of a live attenuated L. intracellularis vaccine (Enterisol Ileitis®) on the health and production parameters of weaned and finishing pigs in a commercial Finnish 850-sow farm with diagnosed L. intracellularis infection. The herd was free from enzootic pneumonia, swine dysentery, progressive atrophic rhinitis, sarcoptic mange and salmonellosis. Four weekly groups of approximately 500 piglets were included in the study for a total of approximately 2000 piglets. Half of these piglets were vaccinated at 3 weeks of age and the other half served as controls. The study piglets were ear-tagged with individual numbers and colour-coded and were individually weighed at weaning (4 weeks), delivery to the finishing farm (12-14 weeks) and at slaughter. Mortality, symptoms of diseases and medications of the study piglets were registered in the nursery and finishing unit. Feed conversion rate was calculated for the finishing period and lean meat percentage was measured at slaughter. Results: Vaccinated piglets had a higher live weight than unvaccinated piglets at delivery to the finishing unit (+ 1.18 kg, P = 0.002) and at slaughter (+ 3.57 kg, P < 0.001). The daily weight gain of vaccinated piglets was better than unvaccinated piglets in the nursery (+ 14.8 g/d, P = 0.013) and in the finishing unit (+ 30.9 g/d, P < 0.001). Vaccination had no effect on feed conversion rate or lean meat percentage (P = 0.102). Altogether, 3.9 and 4.6% of the pigs were medicated for different reasons in the vaccinated and control groups, respectively. The return on investment for the vaccination was calculated to be 0.41. Conclusions: Immunisation of piglets with a live attenuated L. intracellularis vaccine resulted in higher meat yield in pig production via significantly higher live weight and average daily weight gain in a Finnish specific pathogen-free setting. [ABSTRACT FROM AUTHOR]

Biosecurity is defined as the implementation of measures that reduce the risk of disease agents being introduced and/or spread. For pig production, several of these measures are routinely implemented (e.g. cleaning, disinfection, segregation). However, air as a potential vector of pathogens has long been disregarded. Filters for incoming and recirculating air were installed into an already existing ventilation plant at a fattening piggery (3,840 pigs at maximum) in Saxony, Germany. Over a period of three consecutive fattening periods, we evaluated various parameters including air quality indices, environmental and operating parameters, and pig performance. Animal data regarding respiratory diseases, presence of antibodies against influenza A viruses, PRRSV, and Actinobacillus pleuropneumoniae and lung health score at slaughter were recorded, additionally. There were no significant differences (p = 0.824) in total bacterial counts between barns with and without air filtration. Recirculating air filtration resulted in the lowest total dust concentration (0.12 mg/m3) and lung health was best in animals from the barn equipped with recirculating air filtration modules. However, there was no difference in animal performance. Antibodies against all above mentioned pathogens were detected but mostly animals were already antibody-positive at re-stocking. We demonstrated that supply air filtration as well as recirculating air filtration technique can easily be implemented in an already existing ventilation system and that recirculating air filtration resulted in enhanced lung health compared to supply air-filtered and non-filtered barns. A more prominent effect might have been obtained in a breeding facility because of the longer life span of sows and a higher biosecurity level with air filtration as an add-on measure. [ABSTRACT FROM AUTHOR]

The porcine reproductive and respiratory syndrome (PRRS) is an infectious disease that leads to high financial and production losses in the global swine industry. The pathogenesis of this disease is dependent on a multitude of factors, and its control remains problematic. The immune system generally defends against infectious diseases, especially dendritic cells (DCs), which play a crucial role in the activation of the immune response after viral infections. However, the understanding of the immune response and the genetic impact on the immune response to PRRS virus (PRRSV) remains incomplete. In light of this, we investigated the regulation of the host immune response to PRRSV in porcine lung DCs using RNA-sequencing (RNA-Seq). Lung DCs from two different pig breeds (Pietrain and Duroc) were collected before (0 hours) and during various periods of infection (3, 6, 9, 12, and 24 hours post infection (hpi)). RNA-Seq analysis revealed a total of 20,396 predicted porcine genes, which included breed-specific differentially expressed immune genes. Pietrain and Duroc infected lung DCs showed opposite gene expression courses during the first time points post infection. Duroc lung DCs reacted more strongly and distinctly than Pietrain lung DCs during these periods (3, 6, 9, 12 hpi). Additionally, cluster analysis revealed time-dependent co-expressed groups of genes that were involved in immune-relevant pathways. Key clusters and pathways were identified, which help to explain the biological and functional background of lung DCs post PRRSV infection and suggest IL-1β1 as an important candidate gene. RNA-Seq was also used to characterize the viral replication of PRRSV for each breed. PRRSV was able to infect and to replicate differently in lung DCs between the two mentioned breeds. These results could be useful in investigations on immunity traits in pig breeding and enhancing the health of pigs. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is a naturally occurring, fatal neurodegenerative disease of cervids. The potential for swine to serve as hosts for the agent of CWD is unknown. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following experimental oral or intracranial inoculation. Crossbred piglets were assigned to three groups, intracranially inoculated (n=20), orally inoculated (n=19), and noninoculated (n=9). At approximately the age at which commercial pigs reach market weight, half of the pigs in each group were culled ("market weight" groups). The remaining pigs ("aged" groups) were allowed to incubate for up to 73 months postinoculation (mpi). Tissues collected at necropsy were examined for disease-associated prion protein (PrPSc) by Western blotting (WB), antigen capture enzyme immunoassay (EIA), immunohistochemistry (IHC) and in vitro real-time quaking-induced conversion (RT-QuIC). Brain samples from selected pigs were also bioassayed in mice expressing porcine prion protein. Four intracranially inoculated aged pigs and one orally inoculated aged pig were positive by EIA, IHC, and/or WB. By RT-QuIC, PrPSc was detected in lymphoid and/or brain tissue from one or more pigs in each inoculated group. The bioassay was positive in four out of five pigs assayed. This study demonstrates that pigs can support low-level amplification of CWD prions, although the species barrier to CWD infection is relatively high. However, detection of infectivity in orally inoculated pigs with a mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity. IMPORTANCE We challenged domestic swine with the chronic wasting disease agent by inoculation directly into the brain (intracranially) or by oral gavage (orally). Disease-associated prion protein (PrPSc) was detected in brain and lymphoid tissues from intracranially and orally inoculated pigs as early as 8 months of age (6 months postinoculation). Only one pig developed clinical neurologic signs suggestive of prion disease. The amount of PrPSc in the brains and lymphoid tissues of positive pigs was small, especially in orally inoculated pigs. Regardless, positive results obtained with orally inoculated pigs suggest that it may be possible for swine to serve as a reservoir for prion disease under natural conditions. [ABSTRACT FROM AUTHOR]

Live pig trade patterns, drivers and characteristics, particularly in backyard predominant systems, remain largely unexplored despite their important contribution to the spread of infectious diseases in the swine industry. A better understanding of the pig trade dynamics can inform the implementation of risk-based and more cost-effective prevention and control programs for swine diseases. In this study, a semi-structured questionnaire elaborated by FAO and implemented to 487 farmers was used to collect data regarding basic characteristics about pig demographics and live-pig trade among villages in the country of Georgia, where very scarce information is available. Social network analysis and exponential random graph models were used to better understand the structure, contact patterns and main drivers for pig trade in the country. Results indicate relatively infrequent (a total of 599 shipments in one year) and geographically localized (median Euclidean distance between shipments = 6.08 km; IQR = 0–13.88 km) pig movements in the studied regions. The main factors contributing to live-pig trade movements among villages were being from the same region (i.e., local trade), usage of a middleman or a live animal market to trade live pigs by at least one farmer in the village, and having a large number of pig farmers in the village. The identified villages’ characteristics and structural network properties could be used to inform the design of more cost-effective surveillance systems in a country which pig industry was recently devastated by African swine fever epidemics and where backyard production systems are predominant. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome (PRRS) is one of the most significant and economically important infectious diseases affecting swine worldwide and can predispose pigs to secondary bacterial infections caused by, e.g. Haemophilus parasuis. The aim of the presented study was to compare susceptibility of two different types of macrophages which could be in contact with both pathogens during infection with PRRS virus (PRRSV) and in co-infection with H. parasuis. Alveolar macrophages (PAMs) as resident cells provide one of the first lines of defence against microbes invading lung tissue. On the other hand, monocyte derived macrophages (MDMs) represent inflammatory cells accumulating at the site of inflammation. While PAMs were relatively resistant to cytopathogenic effect caused by PRRSV, MDMs were much more sensitive to PRRSV infection. MDMs infected with PRRSV increased expression of pro-apoptotic Bad, Bax and p53 mRNA. Increased mortality of MDMs may be also related to a higher intensity of ROS production after infection with PRRSV. In addition, MDMs (but not PAMs) infected with H. parasuis alone formed multinucleated giant cells (MGC); these cells were not observed in MDMs infected with both pathogens. Higher sensitivity of MDMs to PRRSV infection, which is associated with limited MDMs survival and restriction of MGC formation, could contribute to the development of multifactorial respiratory disease of swine. [ABSTRACT FROM AUTHOR]

Background/Aim Live attenuated vaccines confer partial protection in pigs before the appearance of neutralizing antibodies, suggesting the contribution of cell-mediated immunity (CMI). However, PRRSV-specific T-lymphocyte responses and protective mechanisms need to be further defined. To this end, the hypothesis was tested that PRRSV-specific T-lymphocytes induced by exposure to type-2 PRRSV can recognize diverse isolates. Methods An IFN-gamma ELISpot assay was used to enumerate PRRSV-specific T-lymphocytes from PRRSVSD23983-infected gilts and piglets born after in utero infection against 12 serologically and genetically distinct type-1 and -2 PRRSV isolates. The IFN-gamma ELISpot assay using synthetic peptides spanning all open reading frames of PRRSVSD23983 was utilized to localize epitopes recognized by T-lymphocytes. Virus neutralization tests were carried out using the challenge strain (type-2 PRRSVSD23983) and another strain (type-2 PRRSVVR2332) with high genetic similarity to evaluate cross-reactivity of neutralizing antibodies in gilts after PRRSVSD23983 infection. Results At 72 days post infection, T-lymphocytes from one of three PRRSVSD23983-infected gilts recognized all 12 diverse PRRSV isolates, while T-lymphocytes from the other two gilts recognized all but one isolate. Furthermore, five of nine 14-day-old piglets infected in utero with PRRSVSD23983 had broadly reactive T-lymphocytes, including one piglet that recognized all 12 isolates. Overlapping peptides encompassing all open reading frames of PRRSVSD23983 were used to identify ≥28 peptides with T-lymphocyte epitopes from 10 viral proteins. This included one peptide from the M protein that was recognized by T-lymphocytes from all three gilts representing two completely mismatched MHC haplotypes. In contrast to the broadly reactive T-lymphocytes, neutralizing antibody responses were specific to the infecting PRRSVSD23983 isolate. Conclusion These results demonstrated that T-lymphocytes recognizing antigenically and genetically diverse isolates were induced by infection with a type 2 PRRSV strain (SD23983). If these reponses have cytotoxic or other protective functions, they may help overcome the suboptimal heterologous protection conferred by conventional vaccines. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effects of the addition of the probiotic "Primix Forsil" and the adsorbent "Vitacorm REO" into the feed for young pigs, using different schemes based on the morphological and biochemical parameters of the animal's blood. The scientific and economic experiment took place at the SE "Moldsiungibrid". Forty hybrid gilts of Landrace x Pietrain breed were used as they were separated into 4 groups on the principle of analogy (10 animals in each group). The gilts in the control group were fed the basic ration, while the pigs in the experimental groups were fed a feed supplemented with different substances, namely: the probiotic "Primix Forsil" (0.5 kg/t) - for the pigs in the first group, the adsorbent "Vitacorm REO" (4.0 kg/t) - for the pigs in the second group, and the probiotic "Primix Forsil" and "Vitacorm REO" in equal proportions - for the pigs in the third group. The feed was balanced according to the feeding norms, and modified in compliance with the animals' age and body weight. The obtained results demonstrated that, the supplementation of the fodders for pigs with the adsorbent "Vitacorm REO" both separately or in combination with the probiotic "Primix Forsil", had a good influence on the general level of blood protein. At the end of the experiment, the albumin level as well as that of the AST (Aspartate Aminotransferase) in the blood of the pigs in the experimental groups were higher in comparison with that in the pigs in the control group. [ABSTRACT FROM AUTHOR]

One of the major hurdles to porcine reproductive and respiratory syndrome (PRRS) vaccinology is the limited or no cross-protection conferred by current vaccines. To overcome this challenge, a PRRS chimeric virus (CV) was constructed using an FL12-based cDNA infectious clone in which open reading frames (ORFs) 3-4 and ORFs 5-6 were replaced with the two Korean field isolates K08-1054 and K07-2273,respectively. This virus was evaluated as a vaccine candidate to provide simultaneous protection against two genetically distinct PRRS virus (PRRSV) strains. Thirty PRRS-negative three-week-old pigs were divided into five groups and vaccinated with CV, K08-1054, K07-2273, VR-2332, or a mock inoculum. At 25 days post-vaccination (dpv), the pigs in each group were divided further into two groups and challenged with either K08-1054 or K07-2273. All of the pigs were observed until 42 dpv and were euthanized for pathological evaluation. Overall, the CV-vaccinated group exhibited higher levels of tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and interleukin-12 (IL-12) expression and of serum virus-neutralizing antibodies compared with the other groups after vaccination and also demonstrated better protection levels against both viruses compared with the challenge control group. Based on these results, it was concluded that CV might be an effective vaccine model that can confer a broader range of cross-protection to various PRRSV strains. [ABSTRACT FROM AUTHOR]

Background: Commercial bacterins are widely used at weaning to control Mycoplasma hyopneumoniae infections in pigs. However, it is not known whether the efficacy of vaccinating against M. hyopneumoniae can be influenced by the weaning process when vaccination is applied at the day of weaning. The present study assessed the efficacy of a single M. hyopneumoniae vaccination (Ingelvac MycoFLEX®) three days before weaning (V1) or at weaning (V2) against experimental challenge infection. Four weeks after vaccination, groups V1 and V2 (n =20 pigs each) and a non-vaccinated, positive control group (PCG) (n = 20) were endotracheally inoculated with a virulent M. hyopneumoniae field strain. Five pigs were used as a negative control group. All pigs were euthanized 5 weeks after challenge. The main parameters investigated included macroscopic and histopathological lung lesions at necropsy, immunofluorescence (IF) staining and quantitative real-time PCR (qPCR) on broncho-alveolar lavage (BAL) fluid for quantifying M. hyopneumoniae. Results: The average macroscopic lung lesion scores in groups V1, V2 and PCG were 0.54, 0.88 and 1.04, respectively (P > 0.05). The average lymphohistiocytic infiltration scores in groups V1, V2 and PCG were 2.95, 3.16 and 3.61, respectively (P < 0.05). The average IF scores were: V1 = 1.13, V2 = 1.19 and PCG = 1.25 (P >0.05), the qPCR values were: V1 = 102.94, V2 = 102.76 and PCG = 103.23 (P > 0.05). All pigs of the negative control group remained negative throughout the study. Conclusions: Both vaccinated groups had lower numbers of macroscopic and histopathological lung lesions, and lower numbers of M. hyopneumoniae organisms in the BAL fluid compared to the PCG. However, no firm conclusions could be made on whether weaning negatively influences the efficacy of M. hyopneumoniae vaccination, since significant differences between the treatment groups were only obtained for the histopathological lung lesions. This could be attributed to the fact that milder macroscopic lung lesions were produced in the inoculated pigs, when compared to previous trials conducted by the same group. Further research under field conditions is warranted to assess possible differences between the two vaccination strategies. [ABSTRACT FROM AUTHOR]

The present study was performed to determine the expression of porcine circovirus type 2 (PCV2) antigen in the ovarian tissue of naturally infected gilts. Ovarian tissues were obtained from 11 culled gilts. The ovarian tissues sections were divided into two groups according to PCV2 DNA detection using PCR. PCV2 antigen was assessed in the paraffin embedded ovarian tissue sections by immunohistochemistry. A total of 2,131 ovarian follicles (i.e., 1,437 primordial, 133 primary, 353 secondary and 208 antral follicles), 66 atretic follicles and 131 corpora lutea were evaluated. It was found that PCV2 antigen was detected in 280 ovarian follicles (i.e., 239 primordial follicles, 12 primary follicles, 10 secondary follicles and 19 antral follicles), 1 atretic follicles and 3 corpora lutea (P<0.05). PCV2 antigen was detected in primordial follicles more often than in secondary follicles, atretic follicles and corpora lutea (P<0.05). The detection of PCV2 antigen was found mainly in oocytes. PCV2 antigen was found in both PCV2 DNA positive and negative ovarian tissues. It can be concluded that PCV2 antigen is expressed in all types of the ovarian follicles and corpora lutea. Further studies should be carried out to determine the influence of PCV2 on porcine ovarian function and oocyte quality. [ABSTRACT FROM AUTHOR]

Although breeding of F4 receptor-negative (F4R -) pigs may prevent post-weaning diarrhea, the underlying immunity is poorly understood. Here, various doses of a Bacillus licheniformis and Bacillus subtilis mixture (BLS-mix) were orally administered to F4ab/acR - pigs for 1 week before F4 (K88) - positive ETEC/VTEC/EPEC challenge. Administration of BLS-mix increased the percentage of Foxp3 - IL-10 + T cells but not of Foxp3 + IL-10 + regulatory T (Treg) cells among peripheral blood CD4 + T cells. A low dose of BLS-mix feeding resulted in increased the expression of IL-6, TNF-α, IL-10, and the transcription factors Foxp3 and T-bet mRNAs in the jejunum. Administration of either a low or high dose BLS-mix also led to an increase in the percentage of CD4 + Foxp3 + Treg cells among intraepithelial lymphocytes and CD4 + IL-10 + T cells in the small intestinal Peyer's patches and the lamina propria of F4ab/acR - pigs following F4 + ETEC/VTEC/EPEC challenge. The increased number of IL-10-producing CD4 + T cells was attributed to an increase in the proportion of Foxp3 - IL-10 + Treg cells rather than Foxp3 + IL-10 + Treg cells. Our data indicate that oral administration of BLS-mix to newly weaned F4ab/acR - pigs ameliorates enteritis in an F4 + ETEC/VTEC/EPEC model; however, induction of IL-10-producing Foxp3 - Treg cells by BLS-mix administration cannot account for the protection of newly weaned F4ab/acR - pigs from F4 + ETEC/VTEC/EPEC infection, and that excessive generation of CD4 + IL-10 + T cells following consumption of BLS-mix during episodes of intestinal inflammation that is caused by enteric pathogens might prohibit clearance of the pathogen. Select probiotic mixtures may allow for tailoring strategies to prevent infectious diseases. [ABSTRACT FROM AUTHOR]

Background: Although modified live virus (MLV) vaccines are commonly used for porcine reproductive and respiratory syndrome virus (PRRSV) control, there have been safety concerns due to the quick reversion of MLV to virulence during replication in pigs. Previous studies have demonstrated that mutant viruses emerged from lethal mutagenesis driven by antiviral mutagens and that those viruses had higher genetic stability compared to their parental strains because they acquired resistance to random mutation. Thus, this strategy was explored to stabilize the PRRSV genome in the current study. Results: Four antiviral mutagens (ribavirin, 5-fluorouracil, 5-azacytidine, and amiloride) were evaluated for their antiviral effects against VR2332, a prototype of type 2 PRRSV. Among the mutagens, ribavirin and 5-fluorouracil had significant antiviral effects against VR2332. Consequently, VR2332 was serially passaged in MARC-145 cells in the presence of ribavirin at several concentrations to facilitate the emergence of ribavirin-resistant mutants. Two ribavirin-resistant mutants, RVRp13 and RVRp22, emerged from serial passages in the presence of 0.1 and 0.2 mM ribavirin, respectively. The genetic stability of these resistant mutants was evaluated in MARC-145 cells and compared with VR2332. As expected, the ribavirin-resistant mutants exhibited higher genetic stability compared to their parental virus. Conclusions: In summary, ribavirin and 5-fluorouracil effectively suppressed PRRSV replication in MARC-145 cells. However, ribavirin-resistant mutants emerged when treated with low concentrations (=0.2 mM) of ribavirin, and those mutants were genetically more stable during serial passages in cell culture. [ABSTRACT FROM AUTHOR]

Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) had caused catastrophic losses in swine industry in China. The current inactivated vaccine provided only limited protection, and the attenuated live vaccine could protect piglets against the HP-PRRSV but there was a possibility that the attenuated virus returned to high virulence. In this study, the eukaryotic expression vector pVAX1© was modified under the control of rabbit β-globin intron II gene and the modified vector pMVAX1© was constructed. Porcine interleukin-2 (IL-2) and GP3-GP5 fusion protein of HP-PRRSV strain SD-JN were highly expressed by pMVAX1©. Mice inoculated with pMVAX1©-GP35 developed significantly higher PRRSV-specific antibody responses and T cell proliferation than those vaccinated with pVAX1©-GP35. pMVAX1©-GP35 was selected as PRRS DNA vaccine candidate and co-administrated with pVAX1©-IL-2 or pMVAX1©-IL-2 in pigs. pMVAX1©-IL-2+pMVAX1©-GP35 could provide enhanced PRRSV-specific antibody responses, T cell proliferation, Th1-type and Th2-type cytokine responses and CTL responses than pMVAX1©-GP35 and pVAX1©-IL-2+pMVAX1©-GP35. Following homologous challenge with HP-PRRSV strain SD-JN, similar with attenuated PRRS vaccine group, pigs inoculated with pMVAX1©-IL-2+pMVAX1©-GP35 showed no clinical signs, almost no lung lesions and no viremia, as compared to those in pMVAX1©-GP35 and pVAX1©-IL-2+pMVAX1©-GP35 groups. It indicated that pMVAX1©-IL-2 effectively increases humoral and cell mediated immune responses of pMVAX1©-GP35. Co-administration of pMVAX1©-IL-2 and pMVAX1©-GP35 might be attractive candidate vaccines for preventing HP-PRRSV infections. [ABSTRACT FROM AUTHOR]

Abstract: Outbreaks of highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) have led to large economic losses and, subsequently, have drawn great attention to its diagnosis and prevention. To facilitate rapid discrimination of HP-PRRSV from classical PRRSV (C-PRRSV), we developed a one-step RT-PCR assay. Primer specificities were evaluated with RNA extracted from 8 viral strains and our results revealed that the primers had a high specificity for PRRSV. The assay sensitivity was 25copies/μL for both HP-PRRSV and C-PRRSV. A total of 929 serum samples were identified, of which 20.45% were HP-PRRSV-positive and 1.51% were C-PRRSV-positive, which was completely consistent with that of immunochromatochemistry and sequencing method. The proposed assay can detect the virus 2days prior the onset of symptoms and it can be performed in 2h, thereby providing a rapid method to discriminate HP-PRRSV from C-PRRSV for the identification and prevention of PRRSV infections. [Copyright &y& Elsevier]

Dietary modulation of the synthesis of endogenous host defense peptides (HDPs) represents a novel antimicrobial approach for disease control and prevention, particularly against antibiotic-resistant infections. However, HDP regulation by dietary compounds such as butyrate is species-dependent. To examine whether butyrate could induce HDP expression in pigs, we evaluated the expressions of a panel of porcine HDPs in IPEC-J2 intestinal epithelial cells, 3D4/31 macrophages, and primary monocytes in response to sodium butyrate treatment by real-time PCR. We revealed that butyrate is a potent inducer of multiple, but not all, HDP genes. Porcine β-defensin 2 (pBD2), pBD3, epididymis protein 2 splicing variant C (pEP2C), and protegrins were induced markedly in response to butyrate, whereas pBD1 expression remained largely unaltered in any cell type. Additionally, a comparison of the HDP-inducing efficacy among saturated free fatty acids of different aliphatic chain lengths revealed that fatty acids containing 3–8 carbons showed an obvious induction of HDP expression in IPEC-J2 cells, with butyrate being the most potent and long-chain fatty acids having only a marginal effect. We further investigated a panel of butyrate analogs for their efficacy in HDP induction, and found glyceryl tributyrate, benzyl butyrate, and 4-phenylbutyrate to be comparable with butyrate. Identification of butyrate and several analogs with a strong capacity to induce HDP gene expression in pigs provides attractive candidates for further evaluation of their potential as novel alternatives to antibiotics in augmenting innate immunity and disease resistance of pigs. [ABSTRACT FROM AUTHOR]

The article focuses on a comparative study of the disease trends observed in the Ontario Swine Veterinary-based Surveillance System (OSVS). It states that the submission data reported to the OSVS were compared to the Animal Health Laboratory. It mentions that the need for disease surveillance program in swine in Ontario is to prevent the swine disease associated with a triple-reassortant human-avian-swine influenza H3N2 virus.

Purpose: Porcine proliferative enteropathy (PPE) is known as one of the most important risk factors causing economic losses in swine industry worldwide. This study was conducted to evaluate the efficacy of a commercial oral attenuated Lawsonia intracellularis vaccine (Enterisol Ileitis) against PPE under a commercial pig farm condition in Korea. Materials and Methods: Thirty two-day-old 672 piglets were randomly allocated into vaccinated and control groups. All piglets in the vaccinated group were inoculated with a commercial attenuated L. intracellularis vaccine as following the manufacturer's instruction. Body weights of all pigs in both groups were measured on the vaccination day and 6, 14, and 20 weeks post vaccination and an average daily weight gain (ADWG) was calculated. Health status was observed biweekly during the whole trial. Results: The vaccinated group showed significantly higher body weight (p < 0.05) and ADWG (p < 0.05) than those of the control group. The vaccinated group had significantly reduced impairments in activity, growth, defecation frequency, and stool hardness (p <0.05). Additional health benefits and improved weight gain by the vaccination produced a 4.2:1 return of investment, and the higher gross margin was $4.80 per pig. Conclusion: Our finding suggests that the L. intracellularis vaccine program has effects on the substantial health and economic benefits in the Korean swine industry. [ABSTRACT FROM AUTHOR]

A methodology for scientific analysis and solution of problems was designed on the basis of advanced quality tools. It was applied to a swine production process of raw material supplier for the manufacture of drugs. As a result of the analysis of the main process problem, the low availability of pigs, which fulfilled the health requirements as donors of MPF and most influential in causing respiratory diseases in swine units in the country studied, was identified. Critical Success Factors of this production system coincided with the probable causes of the main problems identified, increasing yield and consistency of the process with the most suitable animals a year, reducing losses by diseases, primarily respiratory, changing current productive paradigm and having suppliers selected and approved to meet a new productive paradigm. Among the alternatives or changes were early slaughter and design of a supplier management process, with selection of official suppliers evaluated with productive paradigm focused on the production of raw material for the manufacture of drugs. To verify and monitor the effectiveness of the redesigned technology system, a system of quality costs was developed, allowing the distribution of costs among the planned activities to ensure and assess the production and failures caused by poor quality. The application of this system shows that in the period, after the redesign of the process, there was a progressive reduction of the costs by failures, achieving a balance between them and evaluation and prevention costs, so they can begin to reduce expenses in these two categories. The results obtained with the swine production process show the feasibility of the methodology designed, since the scientific analysis performed, there was a positive impact in its efficiency and consistency, helping to maintain the quality levels of pharmaceutical products. [ABSTRACT FROM AUTHOR]

The aim of this study was to monitor the presence of M. hyopneumoniae in pig farms during the implementation of eradication programs using different diagnostic techniques focusing on PCR. They worked with a company owner of three farms, a farrow-to-finish (390 sows), a multiple-site (4100 sows) and a new one that was populated its new facility. In the first two were developed a partial depopulation program to eradicate swine enzootic pneumonia, the latter one was populated with pigs after the previous eradication. In the three farms, the pigs were monitored by: serology (ELISA), PCR, macroscopic and microscopic lung lesions and the presence of non-productive cough. The absence of cough, low percentage of seropositive pigs in the finishing stage and the low proportion of lung lesions at slaughter suggest that swine enzootic pneumonia was eradicated, but not the causative agent -M. hyopneumoniae- whose DNA was detected by PCR showing different behaviors according to the herd. [ABSTRACT FROM AUTHOR]

This paper aims to analyze the current situation and plans of control and eradication of classical swine fever in the Americas and the Caribbean as well as the main causes that lead to disease transmission. At present the Classical Swine Fever (CSF) is recognized as a transboundary disease, remains endemic in many countries of Latin America and the Caribbean. In the Americas region remain as affected countries: Nicaragua, Honduras, Brazil, Colombia, Ecuador, Bolivia, Peru and Venezuela. In the Caribbean countries the affected ones are: Cuba, Haiti, and Dominican Republic. There are several causes which hinder the control of CSF, playing a key role the political will of each country and its veterinary service. The control and eradication plans are hampered by the low availability of vaccines, inadequate control of the animal movement and the illegal trade of pigs and their products. These elements contribute to the maintenance of infection and spread of the disease from affected into free areas. [ABSTRACT FROM AUTHOR]

The article discusses the study regarding the production of a candidate protein Ascaris suum 14-kDa protective surface antigen (As14) in rice. It notes that the endosperm-specific glutelin-B promoter controlled the production of a 14-kDa protective surface antigen of Ascaris suum third-stage larvae (L3) together with its fusion chimera a mucosal carrier molecule cholera toxin b subunit (CTB) in rice. The results and the potentials of transgenic rice plants to provide oral vaccines for swine roundworm are explored. It concludes that in order to evaluate the efficacy of the candidate protein for the rice plant-based edible vaccines, oral immunization studies should be carried out.

This experiment was designed to test the effect of polymorphism in the cholesterol 7-alpha hydroxylase (CYP7) gene locus and dietary cholesterol (C) on cerebrum C in neonatal pigs fed sow's milk formulas. Thirty-six pigs (18 male and 18 female) genetically selected for high (HG) or low (LG) plasma total C were weaned at 24-36 h after birth and assigned in a 2 x 2 x 2 factorial arrangement of treatments with 2 diets (0 or 0.5% C), 2 sexes, and 2 genotypes (HG and LG). Individually housed pigs consumed diets ad libitum for 42 d. Open-field behavior was tested at wk 2 and 4. All pigs were killed at 42 d of age, the cerebrum was weighed, and C content and concentration measured. All data were analyzed by general linear model ANOVA. Cerebrum weight was greater in HG than LG pigs (P < 0.03) but was not affected by diet or sex. Pigs fed C tended to have a higher cerebrum C concentration than those deprived (P = 0.12). At 2 wk, LG pigs explored a novel open-field environment less often (P < 0.001) than did HG pigs. At 4 wk, some LG pigs explored the open field but fewer (P < 0.001) vs. HG pigs retreated back to the safe area. There were no genotype x diet, genotype x sex, or diet x sex interactions affecting cerebrum weight, or C content or concentration. Polymorphism in the CYP7 gene locus affected cerebrum weight and behavior and dietary C tended to increase cerebrum C concentration in neonatal pigs. These findings in neonatal pigs have considerable potential importance in human infant nutrition and behavioral development. [ABSTRACT FROM AUTHOR]

The article discusses efforts of Alejandro "Alex" Ramirez, president of American Association of Swine Practitioners, in improving the health and welfare of the pig. It mentions that the association is supporting veterinarians in practice through guidance on decisions that affect the health and care of pigs. It also reveals challenges in dealing with porcine reproductive and respiratory syndrome.

The article discusses a research by animal genetics company Genus, the University of Missouri and the Kansas State University, which examines the immunity of genetically-modified pigs from deadly swine disease in the U.S. The U.S. Food and Drug Administration (FDA) has approve the use of genetically engineered animal intended for sale as food. Also presented were insights of Dr. Bill Christianson, Raymond Rowland and Dr. Tom Burkgren. INSET: Canine cancer drug loses approval.

The epithelial cells of the gut form a monolayer that covers the intestine and has a primary role in protecting against pathogenic challenges, they have developed different mechanisms to reduce the risk of infection such as barrier function. In swine, Salmonella infections can result in disruption of the barrier functioning of the intestinal epithelium. Yeast mannan structurally resemble the receptor sites coating the intestinal epithelium to which intestinal pathogens like salmonella adhere thus preventing infection. The objective of this study was to determine if a commercial mannan rich fraction (MRF, Actigen) extracted from yeast can aid in maintenance of the intestinal epithelial barrier. Porcine intestinal epithelial cells (IPEC J2) between passages 2-18 were seeded into collagen-coated Transwells (Costar, 1.12 cm2) at a density of 2 X 105 cells/well, triplicate wells for control and MRF treatment. Differentiation of monolayers was observed after 9 days in vitro as determined by measuring trans electrical resistance (TEER analysis) when a TEER reading of 20,000 ohm/m2 or greater was achieved. TEER was measured daily using an epithelial volthommeter, ohm/m2. On day 14 of the differentiation, cells were treated with a 1/10 dilution of MRF which was subjected to an in vitro simulated porcine digestion method, where 0.5g of MRF was digested in a volume of 14mL. On day 15 of the differentiation, cells were exposed to LPS from Salmonella (1ug/mL), membrane integrity was monitored by measuring TEER. Day 16 cells were harvested from the transwells, RNA was extracted for gene expression analysis. Control and MRF treated cells saw a drop in TEER readings following LPS exposure; 30,000 & 41,000 ohm/m2 down to 9,100 & 9,000 ohm/m2 respectively. The MRF treated cells recovered their TEER reading 20,500 ohm/m2 following exposure to LPS (p< 0.05) where as no recovery was observed in the control cells 8,700 ohm/m2. Gene expression analysis of genes associated with membrane integrity and barrier function e.g. tight junction's protein gene and occludin were also measured. Tight junction protein gene expression levels were increased three-fold in MRF treated cells compared to control cells exposed to LPS (p< 0.05), the expression level of Occludin was also 1.5 times greater than that of the control cells. Tight junction proteins are known to play a pivotal role in barrier function; the increase in their expression following MRF supplementation together with the TEER recovery may indicate that MRF can positively impact the intestinal epithelium barrier. [ABSTRACT FROM AUTHOR]

The article reports that Michelle L. Sprague, president of the American Association of Swine Veterinarians (AASV), said that two viral diseases deadly to swine and animal welfare debates are the top challenges for swine veterinarians in the U.S. According to her, swine veterinarians are making progress in fighting those diseases and there is a need to continue to advocate for improving technologies.

The article offers suggestions send by a reader in response to a case related to viral enteritis infection in swine population of Canada, asked in the September 2013 issue of the periodical. The reader, an ethicist comments that Canadian government should take effective measure to prevent the spread of disease which has killed over 100,000 swine in the U.S. It also reflects on a case related to emergency fee charged by veterinary practitioner asked by the periodical in the December 2013 issue.

The article discusses the efforts of veterinarians to control air around swine to prevent porcine reproductive and respiratory syndrome (PRRS). Doctor Darwin L. Reicks advised to not allow unfiltered air into the farm. Doctor Scott A. Dee said that swine veterinarians are prepared and can eliminate PRRS and that a voluntary eradication plan could attain that goal. Meanwhile, it mentions that doctor Montserrat Torremorell attempts to devise a vaccine against all PRRS strains.

The article reports on the revival of the Swine Health Advisory Committee in Indiana to discuss how the state can help the swine industry fight porcine reproductive and respiratory syndrome (PRRS). It states that the PRRS subcommittee will be composed of veterinarians from diagnostic laboratories, universities, and private practice. Board of Animal Health chairman John E. Baker adds that the state has the authority to enforce quarantines, livestock testing requirement, and restrict movement.

The article focuses on the economic benefits of swine coccidiosis prevention and treatment using Baycox® 5%. According to Dr. Abdulkerim Deniz, DVM, neonatal piglet coccidiosis causes substantial losses for pork producers. It notes that Baycox® 5% treatment reduces antibiotic and labor costs used for coccidiosis treatments. It also mentions that the use of Baycox® 5% gives producers benefits in the growth stage of the piglets.

The article focuses on pig coccidiosis and the Baycox® 5%. It notes that in the recent International Pig Veterinary Society (IPVS) Congress, reports confirmed that pig coccidiosis causes substantial production losses in pig herds in Canada. It mentions that Baycox® 5% can help pig raisers raise healthy piglets as it prevents coccidial infection.

The article offers information on the swine influenza vaccine, a vaccination intended for swine to fight against swine influenza virus flu (SIV) subtype H1N1.

The article presents information on the results of a study conducted in Ireland regarding the effectiveness of a new vaccine against porcine ileitis in pigs. It states that vaccine used in three pig units showed several benefits including faster growth, improved feed efficiency and an end to scour. According to one of the producers Mark Adams, he vaccinated his piglets when they were three weeks old which resulted in the absence of ileitis and tail biting.