Isolation of Salmonella using pooled pen feces from 37 U.S. swine farms

The purpose of this study was to culture the pooled pen feces of market weight pigs to determine the most common Salmonella serotypes being shed and to see if farms positive by culture were also positive by serology. Isolates were analyzed to determine if they had Oantigens capable of inducing an immune response detectable by the Danish Mix-ELISA. There were a total of 286 isolates of Salmonella recovered, 263 of which shared O-antigens with the Mix-ELISA

Virulence Determination for Rapid Extraintestinal Dissemination (Acute Infection) of Common Salmonella Serotypes in Swine

Salmonella enterica (Typhimurium and Choleraesuis) have been shown to rapidly disseminate extraintestinally (RED) within 3 hours of intranasal inoculation in pigs (1,2,5,6). Evaluation of RED serotypes may be an important indicator of Salmonella virulence. Experimentally, pigs were challenged with important lymph node, fecal, and vaccine isolates of Salmonella and evaluated for RED. These isolates include S. Heidelberg, S. Infantis, S. Derby, S. Worthington, S. 4, 12 imonophasic, S. untypable HL 10416, S. Typhimurium, S. Typhimurium variant Copenhagen, S. Bredeney, S. Muenchen, S. Brandenburg, S. Choleraesuis SC-38, S. Choleraesuis SC-54, and S. Choleraesuis strain Argus. Three hours after intranasal inoculation, the pigs were euthanized, necropsied, and the following tissues were collected for qualitative isolation: tonsil, thymus, blood, mandibular lymph node, lung, spleen, liver, ileocecal lymph node, colon contents, and cecum contents. Fewer tissues were positive for vaccine strains compared with wild type or parent strains

Replicon Particle Porcine Reproductive and Respiratory Syndrome Virus Vaccine Provides Partial Protection from Challenge

Replicon particles (RPs) expressing the GP5 and Matrix structural proteins of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) were created and compared to inactivated PRRSV in a challenge study. Pigs that received the RP vaccine had lower live virus titers and showed lower IDEXX ELISA values following challenge when compared to other groups. These results show that the RP vaccine provided partial protection against challenge with virulent PRRSV. Also, the RP vaccine allows for differentiation between vaccinated and naturally infected animals

Preparation of GP5-M Heterodimer Glycantype Specific Recombinant Protein and Replicon Particles

Porcine Reproductive and Respiratory Syndrome (PRRS) imposes a huge financial burden on the swine industry. Thus, there is a clear and immediate need for improved PRRS virus (PRRSV) vaccines. Our group has proposed a new classification scheme for PRRSV strains that allows for immunological differentiation based on level of GP5 glycosylation. This classification based on glycantype has allowed us to choose PRRSV strains that offer the best chance of protection against PRRS

Experience with the Danish Mix-ELISA in the United States

This article details some of our experiences with Danish mix-ELISA (DME) testing on herds in the United States. In contrast to Denmark, clinical outbreaks of Salmonella Choleraesuis occur in the United States. We examine the appropriateness of the current cut-off of OD%\u3e=40 for U.S. herds by examining serum and fecal samples collected from individual pigs and tested with the DME and culture, respectively. We report the estimated sensitivity and specificity of the DME using the original and possibly modified cut-off values. The 30% cutoff was deemed optimal with a sensitivity of .57 (.45, .82) and a specificity of .84 (.68, .98) for the first set of samples and .69 (.49, .93) and .63 (.53, .76) for the second set of samples. A major use of these tests is for monitoring herds for Salmonella exposure over time. Information on the sensitivity and specificity of the DME is helpful in determining how many animals in a herd to sample and how often

Immunization of Swine with Virus-like Replicon Particles: Proof of Concept

Pigs were inoculated with virus-like replicon particle (VRP) vaccines expressing the influenza hemagglutinin (HA) protein. A robust antibody response was present following the inoculation. These results indicate that VRP vaccines can successfully express a foreign antigen in the pig and induce high antibody titers. This proof of concept work supports the further in vivo evaluation of VRP expressing swine influenza virus (SIV) HA protein as well as VRP co-expressing porcine reproductive and respiratory syndrome virus (PRRSV) GP5 and M proteins as novel vaccines for swine

Probable Donor-Derived Human Adenovirus Type 34 Infection in 2 Kidney Transplant Recipients From the Same Donor.

Human adenovirus type 34 (HAdV-34) infection is a recognized cause of transplant-associated hemorrhagic cystitis and, in rare cases, tubulointerstitial nephritis. The source of such infections is often difficult to assess, that is, whether acquired as a primary infection, exposure to a pathogen in the transplanted organ, or reactivation of an endogenous latent infection. We present here 2 cases of likely transplant-acquired HAdV-34 infection from the same organ donor, manifesting as tubulointerstitial nephritis in 1

Passive Immunization of Piglets with Hyperimmune Plasma Containing Virus Neutralizing Antibodies to Porcine Reproductive and Respiratory Syndrome Virus

Polyvalent hyperimmune plasma (HP) with high-titers of virus neutralizing (VN) antibody to porcine reproductive and respiratory syndrome virus (PRRSV) strains was produced in gilts and used to passively immunize 3 week old piglets. The piglets were subsequently challenged with live virus. Results showed delay of viremia, decrease in live virus titers, decrease in gross lung lesions, or delay in transmission to naïve, non-immunized sentinel pigs

Evaluation of a Virus-like Replicon Particle Vaccine Expressing Proteins of Swine Influenza Virus in Pigs With and Without Maternally Derived Antibodies

A major hurdle to swine influenza vaccination of young piglets is maternal antibody interference. This interference is transient as it disappears when pigs reach about 3 months of age. We vaccinated piglets without and with interfering maternal antibody using a recombinant vector vaccine. In the absence of interfering maternal antibody, the vaccine was effective in inducing a strong immune response and greatly reduced the amount of virus. However, this same recombinant vaccine was not effective when interfering maternal antibodies were present. We are currently trying a higher dose of vaccine and different genes from SIV in hopes we can overcome this maternal antibody. Preliminary data from these new studies are promising

Isolation of Salmonella using pooled pen feces from 37 U.S. swine farms

The purpose of this study was to culture the pooled pen feces of market weight pigs in order to determine the most common Salmonella serotypes being shed and to see if farms positive by culture were also positive by serology. Isolates were analyzed to determine if they had 0-antigens capable of inducing an immune response detectable by the Danish Mix-ELISA