Evaluation of in vivo Hemocyte Phagocytosis of Microsphere Beads in Litopenaeus vannamei Utilizing Flow Cytometry Following Administration of Bacterial Lipopolysaccharides

Carboxylate modified microspheres were injected into shrimp and phagocytosis of these particles was measured using flow cytometry following treatment with microbial lipopolysaccharides. This is the first time these methods have been used to assess innate immune responses in shrim

Experimental Transmission of Necrotizing Hepatopancreatitis Bacteria to Post-Larval Litopeneaus Vannamei

Day 15 specific pathogen free Post-Larval Pacific White Shrimp, Litopeneaus vannamei, were infected with Necrotizing Hepatopancreatitis bacteria (NHPB) by per os exposure. This is the first documented report of controlled post larval (PL) infection and mortality with NHPB

Effects of Fluctuating Temperatures on Isowean Pigs

This study quantifies responses of isowean pigs (10 to 12 days of age, PIC breed) to potential in-transit temperature fluctuations for 54 h, followed by a 14-day growth period under thermoneutrality. The 54-h temperature regimens included a constant air temperature of 26.7°C (as control) and three cyclic air temperatures of 26.7 ± 2.8°C, 26.7 ± 5.6°C and 26.7 ± 8.3°C, all using woodshavings bedding atop rigid board insulation. The pigs received an average dosage of 0.91 kg/pig water replacement supply during the 54-h treatment period, and ad-libitum feeding and watering during the growth period. Pigs in all three treatments and the control had similar growth performance, physiological, and energetic responses during both treatment and growth periods. At the end of the treatment period, the pigs had elevated concentrations of hematocrit, plasma protein, blood urea nitrogen, sodium and chloride, but declined concentration of glucose (P \u3c 0.05). Potassium and bicarbonate levels remained relatively constant (P \u3e 0.05). Concentrations of the blood constituents returned to normal during the growth period. The results suggest that the isowean pigs respond well to air temperature fluctuations of up to ±8.3°C around the thermoneutral condition of 26.7°C air temperature coupled with woodshavings bedding

Sequence-optimized and targeted double-stranded RNA as a therapeutic antiviral treatment against infectious myonecrosis virus in \u3ci\u3eLitopenaeus vannamei\u3c/i\u3e

Infectious myonecrosis virus (IMNV) is a significant and emerging pathogen that has a tremendous impact on the culture of the Pacific white shrimp Litopenaeus vannamei. IMNV first emerged in Brazil in 2002 and subsequently spread to Indonesia, causing large economic losses in both countries. No existing therapeutic treatments or effective interventions currently exist for IMNV. RNA interference (RNAi) is an effective technique for preventing viral disease in shrimp. Here, we describe the efficacy of a double-stranded RNA (dsRNA) applied as an antiviral therapeutic following virus challenge. The antiviral molecule is an optimized dsRNA construct that targets an IMNV sequence at the 5’ end of the genome and that showed outstanding antiviral protection previously when administered prior to infection. At least 50% survival is observed with a low dose of dsRNA administered 48 h post-infection with a lethal dose of IMNV; this degree of protection was not observed when dsRNA was administered 72 h post-infection. Additionally, administration of the dsRNA antiviral resulted in a significant reduction of the viral load in the muscle of shrimp that died from disease or survived until termination of the present study, as assessed by quantitative RT-PCR. These data indicate that this optimized RNAi antiviral molecule holds promise for use as an antiviral therapeutic against IMNV

Studies on Salmonella Infections in Pigs with Emphasis in Food Safety Applications

During the past year, studies have been conducted in the following areas: 1. the seasonal variations in environmental fecal Salmonella in pigs prior to shipment for slaughter 2. identification of groups of pigs that might be at risk for becoming infected with Salmonella 3. comparison of culture and the Danish MIX-ELISA for detection of Salmonella on pig farms 4. efficacy of SC54 vaccination of pigs at one day of age 5. the comparison of culture and the Danish MIX-ELISA for the detection of Salmonella in carcasses at slaughter 6. the impact of Salmonella infections on performanc

Detection of African Swine Fever Virus Antibodies in Serum and Oral Fluid Specimens Using a Recombinant Protein 30 (p30) Dual Matrix Indirect ELISA

In the absence of effective vaccine(s), control of African swine fever caused by African swine fever virus (ASFV) must be based on early, efficient, cost-effective detection and strict control and elimination strategies. For this purpose, we developed an indirect ELISA capable of detecting ASFV antibodies in either serum or oral fluid specimens. The recombinant protein used in the ELISA was selected by comparing the early serum antibody response of ASFV-infected pigs (NHV-p68 isolate) to three major recombinant polypeptides (p30, p54, p72) using a multiplex fluorescent microbead-based immunoassay (FMIA). Non-hazardous (non-infectious) antibody-positive serum for use as plate positive controls and for the calculation of sample-to-positive (S:P) ratios was produced by inoculating pigs with a replicon particle (RP) vaccine expressing the ASFV p30 gene. The optimized ELISA detected anti-p30 antibodies in serum and/or oral fluid samples from pigs inoculated with ASFV under experimental conditions beginning 8 to 12 days post inoculation. Tests on serum (n = 200) and oral fluid (n = 200) field samples from an ASFV-free population demonstrated that the assay was highly diagnostically specific. The convenience and diagnostic utility of oral fluid sampling combined with the flexibility to test either serum or oral fluid on the same platform suggests that this assay will be highly useful under the conditions for which OIE recommends ASFV antibody surveillance, i.e., in ASFV-endemic areas and for the detection of infections with ASFV isolates of low virulence