Effect of levamisole on the number of intestinal goblet cells in weaned pigs experimentally vaccinated against colibacillosis

VALPOTIĆ: Effect of levamisole on the number of intestinal goblet cells in weaned pigs experimentally vaccinated against colibacillosis. Vet. arhiv 79, 543-553, 2009. Postweaning colibacillosis (PWC) is an etiologically complex disease commonly induced by porcine F4ac + enterotoxigenic Escherichia coli (ETEC) for which no effective vaccine is available. The objective of this study was to determine the nonspecific immunomodulatory effect of levamisole in combination with specific intragastric immunization of weaned pigs with a candidate F4ac + non-ETEC oral vaccine on the population of intestinal goblet cells (GC). The pigs were immunized with F4ac + non-ETEC strain, in combination with or without levamisole. Seven days after immunization the pigs were challenged with F4ac + ETEC strain and 14 days following immunization they were euthanatized for sampling of specimens of the small intestine for immunohistochemistry and morphometric analyses. Samples of the ileum were tested for the presence of acidic and neutral carbohydrates, components of mucus produced and secreted by the intestinal goblet cells (GC). The volume density (V) of the PAS V + and AB +/PAS+ GC was determined using the stereological point-counting method. The Vv of the ileal PAS + GC was lowest (0.130 ± 0.075 mm3) in the pigs that were immunized wit

Reproductive Performance of Late Pregnant Gilts Treated with Baypamun© before Farrowing

The aim of this study was to investigate whether the production results of pregnant gilts, grown under commercial farm conditions and moved from the sow keeping unit to the prefarrowing unit, could be increased by non-specific immunization with Baypamun© (Bayer, Leverkusen, Germany; BPM), an immune response modifier (IRM). We used three groups of pregnant gilts that obtained different treatments. Non-treated group A served as control; two experimental groups were treated on Day 6, 4 and 2 (group B), or on Day 5, 3 and 1 (group C), respectively, before their transfer from the sow keeping unit to the prefarrowing unit. The experimental gilts received i.m. 2 ml of IRM BPM, i.e. inactivated Parapoxovis virus (1 x 106.75 TCID50). Throughout the trial, the numbers of liveborn and stillborn piglets and the duration of farrowing were recorded. Variance analysis with the type of treatment as independent variable showed a significant difference between control (group A) and experimental group B in the number of liveborn piglets (P < 0.0001) as well as between group A and group B (P < 0.0001) or group C (P < 0.0001) in the number of stillborn piglets, respectively. No differences in duration of farrowing between groups were recorded

Histomorphometric characteristics of immune cells in small intestine of pigs perorally immunized with vaccine candidate F18ac+ nonenterotoxigenic E. coli strain

Colidiarrhea and colienterotoxemia caused by F4+ and/or F18+ enterotoxigenic E. coli (ETEC) strains are the most prevalent infections of suckling and weaned pigs. Here we tested the immunogenicity and protective effectiveness of attenuated F18ac+ non-ETEC vaccine candidate strain against challenge infection with F4ac+ ETEC strain by quantitative phenotypic analysis of small intestinal leukocyte subsets in weaned pigs. We also evaluated levamisole as an immune response modifier (IRM) and its adjuvanticity when given in the combination with the experimental vaccine. The pigs were parenterally immunized with either levamisole (at days -2, -1 and 0) or with levamisole and perorally given F18ac+ non-ETEC strain (at day 0), and challenged with F4ac+ ETEC strain 7 days later. At day 13 the pigs were euthanatized and sampled for immunohistological/histomorphometrical analyses. Lymphoid CD3+, CD45RA+, CD45RC+, CD21+, IgA+ and myeloid SWC3+ cell subsets were identified in jejunal and ileal epithelium, lamina propria and Peyer’s patches using the avidin-biotin complex method, and their numbers were determined by computer-assisted histomorphometry. Quantitative immunophenotypic analyses showed that levamisole treated pigs had highly increased numbers of jejunal CD3+, CD45RC+ and SWC3+ cells (p<0.05) as compared to those recorded in nontreated control pigs. In the ileum of these pigs we have recorded that only CD21+ cells were significantly increased (p<0.01). The pigs that were treated with levamisole adjuvanted experimental vaccine had significantly increased numbers of all tested cell subsets in both segments of the small intestine. It was concluded that levamisole adjuvanted F18ac+ non-ETEC vaccine was a requirement for the elicitation of protective gut immunity in this model; nonspecific immunization with levamisole was less effective, but confirmed its potential as an IRM