Experimental Ascaris suum infection in the pig: protective memory response after three immunizations and effect of intestinal adult worm population

Abstract

The protective immune response to larval migration in pigs, with or without adult intestinal worm populations, 10 weeks after 3 weekly Ascaris suum inoculations, was studied in 45 pigs. Controlled adult worm populations were achieved by oral transfer of 10 adult worms to previously immunized pigs after anthelmintic drenching. A significant reduction in larval recovery from lungs on day 7, and small intestine on day 14, was observed in immunized pigs compared with previously uninfected control pigs after challenge inoculation. The strong anamnestic response to larval migration was characterized by blood eosinophilia and specific immune responses measured by peripheral blood enzyme-linked immunospot and immunosorbent assays using larval excretory-secretory products and adult body fluid as well as Western blotting with a panel of stage-specific A. suum antigens. Immune detection of a previously unreported 10 kDa band, specific to the L2 larval stage and egg hatch fluid, emerged in all pigs after challenge, while the major adult body fluid constituent, ABA-1, remained unrecognized. No significant effect of an intestinal adult worm burden on the larval recovery after a challenge inoculation or on the immune response before or after challenge inoculation could be detected. These results indicate that a significant protective memory immune response to A. suum challenge inoculation can be induced in pigs, and that this protective immunity is not significantly modulated by the presence of adult parasites in the gut.

Pyrophosphatase of the RoundwormAscaris suumPlays an Essential Role in the Worm's Molting and Development

“…Protective immunity to A. lumbricoides infection has been shown to be associated with high levels of serum IgG and IgE responses (6,16,29). Similar antibody responses have also been reported in animals immunized either by repeated inoculation of A. suum embryonated eggs or by parasite crude or recombinant antigens (25,38,46,47). However, no one has addressed the functional significance of the antigen-specific antibodies in protective responses to Ascaris infection.…”

Effect of heavy metal intoxication on macrophage metabolic activity of mice infected with Ascaris suum

“…Residues of A. suum larvae used to be detectable in granuloma tissue of white spots and the parasite antigens are taken up by inflammatory cells (Frontera et al, 2003). An increased liver pathology is associated to larval reduction in the liver in naturally infected animals and also in experimental infection (Eriksen et al, 1992;Jungersen et al, 1999). We hy-pothesize, that Cd intoxication in our study could initiate an increased fibrogen-collagenogenesis in the liver and cause effective larval entrapment which results in decreased parasite burden.…”

“…Reactive oxygen and reactive nitrogen species, such as superoxide (O 2 -), hydroxyl radical ( . HO), hydrogen peroxide (H 2 O 2 ), nitric oxide (NO), and peroxynitrite (ONOO -) are products that macrophages use to destroy a parasite (Kasten-Jolly & Lawrence, 2014). The aim of this study was to examine the immunotoxic effect of heavy metals (lead, cadmium and mercury) on metabolic activity of macrophages in mice infected with Ascaris suum.…”

Ascaris suuminfections in pigs born and raised on contaminated paddocks

“…Serum was analysed for antibodies against A. suum L 3 -larval excretory/secretory products (L 3 -ESP) using an indirect ELISA as described by Jungersen et al (1999). L 3 -ESP have previously been designated L 2 L 3 -ESP.…”