Correlation of Lawsonia intracellularis positivity in quantitative PCR and herd factors in European pig herds.

Background: Lawsonia intracellularis is causing diarrhea, poor growth and sudden death in pigs. It can be found in most pig populations leading to large economic losses worldwide. Many potential risk factors for the occurrence of disease or seropositivity have been described.

Prevalence of in pig herds in different European countries.

Background: causes large economic losses in the pig industry worldwide. Pigs suffer from reduced daily weight gain, poor feed conversion ratio and increased mortality. The number of affected animals and herds in Europe remains unknown.

Field evaluation of a ready-to-use combined type 2 and vaccine in Denmark - a historical comparison of productivity parameters in 20 nursery and 23 finishing herds.

Background: In practice, field evaluation of vaccine efficacy in individual herds is often based on a historical comparison of productivity data following initiation of vaccination. Being biased by time, this study design highly contrasts the more controlled, parallel-group design used for most initial vaccine efficacy studies but offers the possibility of including a larger number of animals and herds. As an important add-on to previous findings in controlled studies, the objective of this study was to evaluate the field efficacy of the ready-to-use combination vaccine Porcilis® PCV M Hyo (MSD Animal Health) by an observational historical study design using routinely generated herd productivity data.

Field evaluation of piglet vaccination with a bacterin as compared to a ready-to-use product including porcine circovirus 2 and in a conventional French farrow-to-finish farm.

Background: A controlled randomized trial was performed on a well-managed conventional French 180-sow farm. The trial compared the growth performances of piglets vaccinated at weaning (single shot) either with a commercial monovalent bacterin vaccine or with a commercial bivalent vaccine (Porcilis® PCV M Hyo) against and porcine circovirus 2 (PCV2). The farm's porcine reproductive and respiratory syndrome status was stable, and most diseases (enzootic pneumonia, atrophic rhinitis, post-weaning multisystemic wasting syndrome) were controlled by routine vaccination.

A field efficacy and safety trial in the Netherlands in pigs vaccinated at 3 weeks of age with a ready-to-use porcine circovirus type 2 and combined vaccine.

Background: Respiratory diseases impair the health and welfare of growing pigs and impacts farmers' gains worldwide. Their control through a preventative medical approach has to be tailored according to the pathogens identified at farm level. In the Netherlands, several studies have emphasized the prominent role of , Porcine Circovirus type 2 and Porcine Reproductive and Respiratory Syndrome Virus in such respiratory conditions.

Field study on the safety and efficacy of intradermal versus intramuscular vaccination against .

The present study compares the safety and efficacy of a needle-free, intradermal vaccine to an intramuscular one. 420 piglets (21+3 days of age) were randomly assigned to two vaccination groups (intradermal vaccination V1 (n=138), intramuscular vaccination V2 (n=144)) and one unvaccinated control group (CG, n=138). As safety parameters clinical observations, local injection site reactions (ISR) and rectal temperatures were assessed.

Field efficacy of Porcilis® PCV M Hyo versus a licensed commercially available vaccine and placebo in the prevention of PRDC in pigs on a French farm: a randomized controlled trial.

Background: A controlled, randomised, and blinded trial performed on a conventional French farrow-to-finish farm compared the efficacy of a one-shot bivalent ready to use vaccine, Porcilis® PCV M. Hyo (group PCVM), to that of two commercial vaccines (Ingelvac® Circoflex® + Ingelvac® Mhyo, group ICIM), and to a placebo (group CTL), in preventing the health and economic impacts of Porcine Respiratory Disease Complex (PRDC).

Material & Methods: In this small-scale clinical study, all piglets in each group were administered the vaccine/placebo at weaning age (27 days old).

Protective immunity to Salmonella enterica is partially serogroup specific.

Pre-harvest reduction of Salmonella carriage by swine would benefit both animal health and food quality. While vaccination is an attractive pre-harvest intervention to reduce Salmonella levels in swine, the large number of potential Salmonella enterica serovars found in swine makes it critical that vaccines provide broad serotype efficacy. In order to directly compare the relative efficacy of Salmonella vaccines against serogroup-matched and serogroup-unmatched Salmonella, we vaccinated pigs with two commercially available Salmonella vaccines (either serogroup B or serogroup C1) and challenged with serovar-matched, serogroup-matched or serogroup-unmatched challenge strains.

Efficacy of vaccination of cattle with the Leptospira interrogans serovar hardjo type hardjoprajitno component of a pentavalent Leptospira bacterin against experimental challenge with Leptospira borgpetersenii serovar hardjo type hardjo-bovis.

Objective: To evaluate the efficacy of vaccination with the Leptospira interrogans serovar hardjo type hardjoprajitno component of a pentavalent Leptospira bacterin against a virulent experimental challenge with Leptospira borgpetersenii serovar hardjo type hardjo-bovis strain 203 in cattle.

Animals: Fifty-five 6-month-old Holstein heifers.

Procedures: Heifers that were negative for persistent infection with bovine viral diarrhea virus determined via immunohistochemical testing and negative for Leptospira interrogans serovar pomona, Leptospira interrogans serovar hardjo, Leptospira interrogans serovar grippotyphosa, Leptospira interrogans serovar bratislava, Leptospira interrogans serovar canicola, and Leptospira interrogans serovar icterohaemorrhagiae determined via microscopic agglutination assay were enrolled in the study.

Insertion and deletion in a non-essential region of the nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome (PRRS) virus: effects on virulence and immunogenicity.

Developing a vaccine that can differentiate infected and vaccinated animals (DIVA) is a new challenge in the design of a vaccine for porcine reproductive and respiratory syndrome virus (PRRSV). Nonstructural protein 2 (nsp2) is the single largest viral product, and it has multiple roles in polypeptide processing and replication complex formation. Using reverse genetics and an infectious PRRSV cDNA clone, we constructed several deletion mutants in the non-essential region of nsp2.

Functional mapping of the porcine reproductive and respiratory syndrome virus capsid protein nuclear localization signal and its pathogenic association.

PRRSV (porcine reproductive and respiratory syndrome virus) nucleocapsid (N) protein is the most abundant structural protein of the virus. During infection, the N protein is specifically localized to the nucleus and nucleolus in addition to its normal cytoplasmic distribution. Previously, a nuclear localization signal (NLS, 41-PGKK(N/S)KKKN)-null mutant virus (41-PGGGNKKKN) showed reduced viremia and increased production of neutralizing antibodies in infected pigs.

CD163 expression confers susceptibility to porcine reproductive and respiratory syndrome viruses.

Direct functional screening of a cDNA expression library derived from primary porcine alveolar macrophages (PAM) revealed that CD163 is capable of conferring a porcine reproductive and respiratory syndrome virus (PRRSV)-permissive phenotype when introduced into nonpermissive cells. Transient-transfection experiments showed that full-length CD163 cDNAs from PAM, human U937 cells (histiocytic lymphoma), African green monkey kidney cells (MARC-145 and Vero), primary mouse peritoneal macrophages, and canine DH82 (histocytosis) cells encode functional virus receptors. In contrast, CD163 splice variants without the C-terminal transmembrane anchor domain do not provide PRRSV receptor function.

Mutations within the nuclear localization signal of the porcine reproductive and respiratory syndrome virus nucleocapsid protein attenuate virus replication.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an RNA virus replicating in the cytoplasm, but the nucleocapsid (N) protein is specifically localized to the nucleus and nucleolus in virus-infected cells. A 'pat7' motif of 41-PGKK(N/S)KK has previously been identified in the N protein as the functional nuclear localization signal (NLS); however, the biological consequences of N protein nuclear localization are unknown. In the present study, the role of N protein nuclear localization during infection was investigated in pigs using an NLS-null mutant virus.

Construction and evaluation of genetically engineered replication-defective porcine reproductive and respiratory syndrome virus vaccine candidates.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an emerging pathogen causing significant economic losses in the swine industry worldwide. Two novel gene-deleted viruses were constructed and evaluated as vaccine candidates. Using the full-length infectious cDNA clone of North American PRRS isolate P129, the ORF2 and ORF4 genes (which encoded minor structural glycoproteins GP2a/2b and GP4, respectively) were individually deleted from the viral genome.

Respiratory symptoms and airway obstruction in swine veterinarians: a persistent problem.

Objective: There are many occupational hazards associated with the practice of swine veterinarians. To reassess the prevalence of respiratory complaints and pulmonary function abnormalities in this group.

Methods: This was a cross-sectional study conducted during the American Association of Swine Veterinarians annual meeting.

Comparison of embryonated chicken eggs with MDCK cell culture for the isolation of swine influenza virus.

Embryonated chicken eggs (ECE) and the Madin-Darby canine kidney (MDCK) cell line were compared for isolation of swine influenza virus (SIV) from nasal swabs and tissue samples. Samples originated from 30 pigs experimentally inoculated with 2 x 106 to 2 x 10(7) embryo infectious dose 50% (EID50)/mL of swine influenza strain A/Swine/Indiana/1726/88 (H1N1). The results were analyzed with McNemar's chi-squared test for symmetry.