The structure of the intestine of Nematodirus battus and changes during the course of aninfection in lambs

Abstract

SUMMARYThe structure of the intestine of adult Nematodirus battus is described. It is similar tothe intestine of some other trichostrongyles but with a few minor differences. Changes in the structure of the intestinal cells are described in N. battus taken from lambs during the later stages of an infection (days 20 to 32) with 60000 infected larvae. The mostnoticeable changes were a decrease in the amounts of glycogen and smooth endoplasmic reticulum, a reduction in the numbers of secretory-type granules and the appearance of vacuoles within the cells. Some of these vacuoles contained small crystals, and crystals, some of them large, were also found in the intestinal lumen. These changes, with the exception of the appearance of the crystals, are similar to changes described for Nippostrongylus brasiliensis affected by the immune response of the rat host, and it is concluded that the changes in N. battus could have been initiated by an immune response to this nematode in the lamb. Lambs given 2000 larvae of N. battus do not reject the nematodes in 32 days, and no changes were observed in the structure of these nematodes.

The occurrence of submicrovillar endotube (modified terminal web) and associated cytoskeletal structures in the intestinal epithelia of nematodes

“…The intestine of Nematodirus is oligocytous (Lee & M artin 1980). It is some 50-80 pm in overall diam eter (figure 6 a,b).The luminal surface is visible within the intact intestine continuous with the endotube which may be exposed by blunt dissection (figure 6 c).…”

Vaccination of young lambs by means of a protein fraction extracted from adultHaemonchus contortus

“…Activitj' of antibodies against the parasite gut wall is not of itself novel; in the much studied rodent-Nippostrongylus model structural changes in the intestine have been shown to be related to functional changes and the subsequent expulsion of the adult worms (Ogilvie & Hockley, 1968;Lee, 1969;Henney, Maclean & Mulligan, 1971). Similar changes in the gut of Trichinella and Nematodirus have also been attributed to the activity of some immune system (Love, Ogilvie & McLaren, 1976;Lee & Martin, 1980). Seesee, Wescott & Garham (1976) have shown binding of antibodies of various classes to sections of the gut, especially the microvilli of the intestinal cells.…”

Nematodirus battus: structure of the body wall of the adult

“…The longitudinal ridges on the cuticle of N. battus may have arsimilar function. N. battus lives closely applied to the intestinal mucosa (Martin & Lee 1980 a) and although this nematode does not have any biting or rasping mouth parts, local abrasions and necrosis of the mucosa has been observed in the vicinity of the worms (Coop, Angus & Mapes, 1973).…”

“…The diagnostic characteristics of N. battus were described by Crofton & Thomas (1951, 1954 and Martin & Lee (19806, c). Lee & Martin (1980) have described the structure of the male reproductive system and of the intestinal tract of this nematode during the course of an infection in young lambs. This paper describes the surface morphology and ultrastructure of the body wall of male and female N. battus.…”